Organic Gardener's Composting
by Steve Solomon
Back in the '70's, I made the momentous move from the East Coast to
the West and quickly discovered that much of my garden knowledge
needed an update. Seattle's climate was unlike anything I had
experienced in Massachusetts or Ohio or Colorado, and many of my
favorite vegetables simply didn't grow well. A friend steered me to
a new seed company, a tiny business called Territorial Seed, unique
in that, rather than trying to tout its wares all over the country,
it would only sell to people living west of the Cascade Mountains.
Every vegetable and cover crop listed had been carefully tested and
selected by Steve Solomon for its performance in the maritime
The 1980's saw the revival of regional gardening, a concept once
widely accepted, but since lost to the sweeping homogeneity of the
'50s and '60s. Steve Solomon and his Territorial Seed Company
directly influenced the return of regional garden making by creating
an awareness of climatic differences and by providing quantities of
helpful information specific to this area. Not only could customers
order regionally appropriate, flavorful and long-lasting vegetables
from the Territorial catalog's pages, we could also find recipes for
cooking unfamiliar ones, as well as recipes for building organic
fertilizers of all sorts. Territorial's catalog offered information
about organic or environmentally benign pest and disease controls,
seasonal cover crops, composts and mulches, and charts guiding us to
optimal planting patterns. Every bit of it was the fruit of Steve
Solomon's work and observation. I cannot begin to calculate the
disappointments and losses Steve helped me to avoid, nor the hours
of effort he saved for me and countless other regional gardeners. We
came to rely on his word, for we found we could; If Steve said this
or that would grow in certain conditions, by gum, it would. Better
yet, if he didn't know something, or was uncertain about it, he said
so, and asked for our input. Before long, a network of
environmentally concerned gardeners had formed around Territorial's
customer base, including several Tilth communities, groups of
gardeners concerned with promoting earth stewardship and organic
husbandry in both rural and urban settings.
In these days of generalized eco-awareness, it is easy to forget
that a few short years ago, home gardeners were among the worst
environmental offenders, cheerfully poisoning anything that annoyed
them with whatever dreadful chemical that came to hand, unconscious
of the long-term effects on fauna and flora, water and soil. Now,
thank goodness, many gardeners know that their mandate is to heal
the bit of earth in their charge. Composting our home and garden
wastes is one of the simplest and most beneficial things we can do,
both to cut down the quantity of wastes we produce, and to restore
health to the soil we garden upon I can think of no better guide to
the principles and techniques of composting than Steve Solomon.
Whether you live in an urban condo or farm many acres, you will find
in these pages practical, complete and accessible information that
serves your needs, served up with the warmth and gentle humor that
characterizes everything Steve does.
Ann Lovejoy, Bainbridge Island, Washington, 1993
To My Readers
A few special books live on in my mind. These were always enjoyable
reading. The author's words seemed to speak directly to me like a
good friend's conversation pouring from their eyes, heart and soul.
When I write I try to make the same thing happen for you. I imagine
that there is an audience hearing my words, seated in invisible
chairs behind my word processor. You are part of that group. I
visualize you as solidly as I can. I create by talking to you.
It helps me to imagine that you are friendly, accepting, and
understand my ideas readily. Then I relax, enjoy writing to you and
proceed with an open heart. Most important, when the creative
process has been fun, the writing still sparkles when I polish it up
the next day.
I wrote my first garden book for an audience of one: what seemed a
very typical neighbor, someone who only thought he knew a great deal
about raising vegetables. Constitutionally, he would only respect
and learn from a capital "A" authority who would direct him
step-by-step as a cookbook recipe does. So that is what I pretended
to be. The result was a concise, basic regional guide to year-round
vegetable production. Giving numerous talks on gardening and
teaching master gardener classes improved my subsequent books. With
this broadening, I expanded my imaginary audience and filled the
invisible chairs with all varieties of gardeners who had differing
needs and goals.
This particular book gives me an audience problem. Simultaneously I
have two quite different groups of composters in mind. What one set
wants the other might find boring or even irritating. The smaller
group includes serious food gardeners like me. Vegetable gardeners
have traditionally been acutely interested in composting, soil
building, and maintaining soil organic matter. We are willing to
consider anything that might help us grow a better garden and we
enjoy agricultural science at a lay person's level.
The other larger audience, does not grow food at all, or if they do
it is only a few tomato plants in a flower bed. A few are apartment
dwellers who, at best, keep a few house plants. Yet even renters may
want to live with greater environmental responsibility by avoiding
unnecessary contributions of kitchen garbage to the sewage treatment
system. Similarly, modern home owners want to stop sending yard
wastes to landfills. These days householders may be offered
incentives (or threatened with penalties) by their municipalities to
separate organic, compostable garbage from paper, from glass, from
metal or from plastic. Individuals who pay for trash pickup by
volume are finding that they can save considerable amounts of money
by recycling their own organic wastes at home.
The first audience is interested in learning about the role of
compost in soil fertility, better soil management methods and
growing healthier, more nutritious food. Much like a serious home
bread baker, audience one seeks exacting composting recipes that
might result in higher quality. Audience two primarily wants to know
the easiest and most convenient way to reduce and recycle organic
Holding two conflicting goals at once is the fundamental definition
of a problem. Not being willing to abandon either (or both) goals is
what keeps a problem alive. Different and somewhat opposing needs of
these two audiences make this book somewhat of a problem. To
compensate I have positioned complex composting methods and the
connections between soil fertility and plant health toward the back
of the book. The first two-thirds may be more than sufficient for
the larger, more casual members of my imaginary audience. But I
could not entirely divide the world of composting into two
completely separate levels.
Instead, I tried to write a book so interesting that readers who do
not food garden will still want to read it to the end and will
realize that there are profound benefits from at-home food
production. These run the gamut from physical and emotional health
to enhanced economic liberty. Even if it doesn't seem to
specifically apply to your recycling needs, it is my hope that you
will become more interested in growing some of your own food. I
believe we would have a stronger, healthier and saner country if
more liberty-loving Americans would grow food gardens.
What Is Compost
Do you know what really happens when things rot? Have other garden
books confused you with vague meanings for words like "stabilized
humus?" This book won't. Are you afraid that compost making is a
nasty, unpleasant, or difficult process? It isn't.
A compost pile is actually a fast-track method of changing crude
organic materials into something resembling soil, called humus. But
the word "humus" is often misunderstood, along with the words
"compost," and "organic matter." And when fundamental ideas like
these are not really defined in a person's mind, the whole subject
they are a part of may be confused. So this chapter will clarify
Compost making is a simple process. Done properly it becomes a
natural part of your gardening or yard maintenance activities, as
much so as mowing the lawn. And making compost does not have to take
any more effort than bagging up yard waste.
Handling well-made compost is always a pleasant experience. It is
easy to disregard compost's vulgar origins because there is no
similarity between the good-smelling brown or black crumbly
substance dug out of a compost pile and the manure, garbage, leaves,
grass clippings and other waste products from which it began.
Precisely defined, composting means 'enhancing the consumption of
crude organic matter by a complex ecology of biological
decomposition organisms.' As raw organic materials are eaten and
re-eaten by many, many tiny organisms from bacteria (the smallest)
to earthworms (the largest), their components are gradually altered
and recombined. Gardeners often use the terms organic matter,
compost, and humus as interchangeable identities. But there are
important differences in meaning that need to be explained.
This stuff, this organic matter we food gardeners are vitally
concerned about, is formed by growing plants that manufacture the
substances of life. Most organic molecules are very large, complex
assemblies while inorganic materials are much simpler. Animals can
break down, reassemble and destroy organic matter but they cannot
create it. Only plants can make organic materials like cellulose,
proteins, and sugars from inorganic minerals derived from soil, air
or water. The elements plants build with include calcium, magnesium,
potassium, phosphorus, sodium, sulfur, iron, zinc, cobalt, boron,
manganese, molybdenum, carbon, nitrogen, oxygen, and hydrogen.
So organic matter from both land and sea plants fuels the entire
chain of life from worms to whales. Humans are most familiar with
large animals; they rarely consider that the soil is also filled
with animal life busily consuming organic matter or each other. Rich
earth abounds with single cell organisms like bacteria,
actinomycetes, fungi, protozoa, and rotifers. Soil life forms
increase in complexity to microscopic round worms called nematodes,
various kinds of mollusks like snails and slugs (many so tiny the
gardener has no idea they are populating the soil), thousands of
almost microscopic soil-dwelling members of the spider family that
zoologists call arthropods, the insects in all their profusion and
complexity, and, of course, certain larger soil animals most of us
are familiar with such as moles. The entire sum of all this organic
matter: living plants, decomposing plant materials, and all the
animals, living or dead, large and small is sometimes called
_biomass._ One realistic way to gauge the fertility of any
particular soil body is to weigh the amount of biomass it sustains.
_Humus_ is a special and very important type of decomposed organic
matter. Although scientists have been intently studying humus for a
century or more, they still do not know its chemical formula. It is
certain that humus does not have a single chemical structure, but is
a very complex mixture of similar substances that vary according to
the types of organic matter that decayed, and the environmental
conditions and specific organisms that made the humus.
Whatever its varied chemistry, all humus is brown or black, has a
fine, crumbly texture, is very light-weight when dry, and smells
like fresh earth. It is sponge-like, holding several times its
weight in water. Like clay, humus attracts plant nutrients like a
magnet so they aren't so easily washed away by rain or irrigation.
Then humus feeds nutrients back to plants. In the words of soil
science, this functioning like a storage battery for minerals is
called cation exchange capacity. More about that later.
Most important, humus is the last stage in the decomposition of
organic matter. Once organic matter has become humus it resists
further decomposition. Humus rots slowly. When humus does get broken
down by soil microbes it stops being organic matter and changes back
to simple inorganic substances. This ultimate destruction of organic
matter is often called nitrification because one of the main
substances released is nitrate--that vital fertilizer that makes
plants grow green and fast.
Probably without realizing it, many non-gardeners have already
scuffed up that thin layer of nearly pure humus forming naturally on
the forest floor where leaves and needles contact the soil. Most
Americans would be repelled by many of the substances that decompose
into humus. But, fastidious as we tend to be, most would not be
offended to barehandedly cradle a scoop of humus, raise it to the
nose, and take an enjoyable sniff. There seems to be something built
into the most primary nature of humans that likes humus.
In nature, the formation of humus is a slow and constant process
that does not occur in a single step. Plants grow, die and finally
fall to earth where soil-dwelling organisms consume them and each
other until eventually there remains no recognizable trace of the
original plant. Only a small amount of humus is left, located close
to the soil's surface or carried to the depths by burrowing
earthworms. Alternately, the growing plants are eaten by animals
that do not live in the soil, whose manure falls to the ground where
it comes into contact with soil-dwelling organisms that eat it and
each other until there remains no recognizable trace of the original
material. A small amount of humus is left. Or the animal itself
eventually dies and falls to the earth where ....
Composting artificially accelerates the decomposition of crude
organic matter and its recombination into humus. What in nature
might take years we can make happen in weeks or months. But compost
that seems ready to work into soil may not have quite yet become
humus. Though brown and crumbly and good-smelling and well
decomposed, it may only have partially rotted.
When tilled into soil at that point, compost doesn't act at once
like powerful fertilizer and won't immediately contribute to plant
growth until it has decomposed further. But if composting is allowed
to proceed until virtually all of the organic matter has changed
into humus, a great deal of biomass will be reduced to a relatively
tiny remainder of a very valuable substance far more useful than
For thousands of years gardeners and farmers had few fertilizers
other than animal manure and compost. These were always considered
very valuable substances and a great deal of lore existed about
using them. During the early part of this century, our focus changed
to using chemicals; organic wastes were often considered nuisances
with little value. These days we are rediscovering compost as an
agent of soil improvement and also finding out that we must compost
organic waste materials to recycle them in an ecologically sound
The closest analogies to composting I can imagine are concocting
similar fermented products like bread, beer, or sauerkraut. But
composting is much less demanding. Here I can speak with authority,
for during my era of youthful indiscretions I made homebrews good
enough have visitors around my kitchen table most every evening.
Now, having reluctantly been instructed in moderation by a liver
somewhat bruised from alcohol, I am the family baker who turns out
two or three large, rye/wheat loaves from freshly ground grain every
week without fail.
Brew is dicey. Everything must be sterilized and the fermentation
must go rapidly in a narrow range of temperatures. Should stray
organisms find a home during fermentation, foul flavors and/or
terrible hangovers may result. The wise homebrewer starts with the
purest and best-suited strain of yeast a professional laboratory can
supply. Making beer is a process suited to the precisionist
mentality, it must be done just so. Fortunately, with each batch we
use the same malt extracts, the same hops, same yeast, same
flavorings and, if we are young and foolish, the same monosaccarides
to boost the octane over six percent. But once the formula is found
and the materials worked out, batch after batch comes out as
So it is with bread-making. The ingredients are standardized and
repeatable. I can inexpensively buy several bushels of wheat- and
rye-berries at one time, enough to last a year. Each sack from that
purchase has the same baking qualities. The minor ingredients that
modify my dough's qualities or the bread's flavors are also
repeatable. My yeast is always the same; if I use sourdough starter,
my individualized blend of wild yeasts remains the same from batch
to batch and I soon learn its nature. My rising oven is always close
to the same temperature; when baking I soon learn to adjust the oven
temperature and baking time to produce the kind of crust and
doneness I desire. Precisionist, yes. I must bake every batch
identically if I want the breads to be uniformly good. But not
impossibly rigorous because once I learn my materials and oven, I've
got it down pat.
Composting is similar, but different and easier. Similar in that
decomposition is much like any other fermentation. Different in that
the home composter rarely has exactly the same materials to work
with from batch to batch, does not need to control the purity and
nature of the organisms that will do the actual work of humus
formation, and has a broad selection of materials that can go into a
batch of compost. Easier because critical and fussy people don't eat
or drink compost, the soil does; soil and most plants will, within
broad limits, happily tolerate wide variations in compost quality
Some composters are very fussy and much like fine bakers or skilled
brewers, take great pains to produce a material exactly to their
liking by using complex methods. Usually these are food gardeners
with powerful concerns about health, the nutritional quality of the
food they grow and the improved growth of their vegetables. However,
there are numerous simpler, less rigorous ways of composting that
produce a product nearly as good with much less work. These more
basic methods will appeal to the less-committed backyard gardener or
the homeowner with lawn, shrubs, and perhaps a few flower beds. One
unique method suited to handling kitchen garbage--vermicomposting
(worms)--might appeal even to the ecologically concerned apartment
dweller with a few house plants.
An Extremely Crude Composting Process
I've been evolving a personally-adapted composting system for the
past twenty years. I've gone through a number of methods. I've used
and then abandoned power chipper/shredders, used home-made bins and
then switched to crude heaps; I've sheet composted, mulched, and
used green manure. I first made compost on a half-acre lot where
maintaining a tidy appearance was a reasonable concern. Now, living
in the country, I don't have be concerned with what the neighbors
think of my heaps because the nearest neighbor's house is 800 feet
from my compost area and I live in the country because I don't much
care to care what my neighbors think.
That's why I now compost so crudely. There are a lot of refinements
I could use but don't bother with at this time. I still get fine
compost. What follows should be understood as a description of my
unique, personal method adapted to my temperament and the climate I
live in. I start this book off with such a simple example because I
want you to see how completely easy it can be to make perfectly
usable compost. I intend this description for inspiration, not
I am a serious food gardener. Starting in spring I begin to
accumulate large quantities of vegetation that demand handling.
There are woody stumps and stalks of various members of the cabbage
family that usually overwinter in western Oregon's mild winters.
These biennials go into bloom by April and at that point I pull them
from the garden with a fair amount of soil adhering to the roots.
These rough materials form the bottom layer of a new pile.
Since the first principle of abundant living is to produce two or
three times as much as you think you'll need, my overly-large garden
yields dozens and dozens of such stumps and still more dozens of
uneaten savoy cabbages, more dozens of three foot tall Brussels
sprouts stalks and cart loads of enormous blooming kale plants. At
the same time, from our insulated but unheated garage comes buckets
and boxes of sprouting potatoes and cart loads of moldy uneaten
winter squashes. There may be a few crates of last fall's withered
apples as well. Sprouting potatoes, mildewed squash, and shriveled
apples are spread atop the base of brassica stalks.
I grow my own vegetable seed whenever possible, particularly for
biennials such as brassicas, beets and endive. During summer these
generate large quantities of compostable straw after the seed is
thrashed. Usually there is a big dry bean patch that also produces a
lot of straw. There are vegetable trimmings, and large quantities of
plant material when old spring-sown beds are finished and the soil
is replanted for fall harvest. With the first frost in October there
is a huge amount of garden clean up.
As each of these materials is acquired it is temporarily placed next
to the heap awaiting the steady outpourings from our 2-1/2 gallon
kitchen compost pail. Our household generates quite a bit of
garbage, especially during high summer when we are canning or
juicing our crops. But we have no flies or putrid garbage smells
coming from the compost pile because as each bucketful is spread
over the center of the pile the garbage is immediately covered by
several inches of dried or wilted vegetation and a sprinkling of
By October the heap has become about six feet high, sixteen feet
long and about seven feet wide at the base. I've made no attempt to
water this pile as it was built, so it is quite dry and has hardly
decomposed at all. Soon those winter rains that the Maritime
northwest is famous for arrive. From mid-October through mid-April
it drizzles almost every day and rains fairly hard on occasion. Some
45 inches of water fall. But the pile is loosely stacked with lots
of air spaces within and much of the vegetation started the winter
in a dry, mature form with a pretty hard "bark" or skin that resists
decomposition. Winter days average in the high 40s, so little
Still, by next April most of the pile has become quite wet. Some
garbagey parts of it have decomposed significantly, others not at
all; most of it is still quite recognizable but much of the
vegetation has a grayish coating of microorganisms or has begun to
turn light brown. Now comes the only two really hard hours of
compost-making effort each year. For a good part of one morning I
turn the pile with a manure fork and shovel, constructing a new pile
next to the old one.
First I peel off the barely-rotted outer four or five inches from
the old pile; this makes the base of the new one. Untangling the
long stringy grasses, seed stalks, and Brussels sprout stems from
the rest can make me sweat and even curse, but fortunately I must
stop occasionally to spray water where the material remains dry and
catch my wind. Then, I rearrange the rest so half-decomposed
brassica stumps and other big chunks are placed in the center where
the pile will become the hottest and decomposition will proceed most
rapidly. As I reform the material, here and there I lightly sprinkle
a bit of soil shoveled up from around the original pile. When I've
finished turning it, the new heap is about five feet high, six feet
across at the bottom, and about eight feet long. The outside is then
covered with a thin layer of crumbly, black soil scraped up where
the pile had originally stood before I turned it.
Using hand tools for most kinds of garden work, like weeding,
cultivating, tilling, and turning compost heaps is not as difficult
or nearly as time consuming as most people think if one has the
proper, sharp tools. Unfortunately, the knowledge of how to use hand
tools has largely disappeared. No one has a farm-bred grandfather to
show them how easy it is to use a sharp shovel or how impossibly
hard it can be to drive a dull one into the soil. Similarly, weeding
with a _sharp_ hoe is effortless and fast. But most new hoes are
sold without even a proper bevel ground into the blade, much less
with an edge that has been carefully honed. So after working with
dull shovels and hoes, many home food growers mistakenly conclude
that cultivation is not possible without using a rotary tiller for
both tillage and weeding between rows. But instead of an expensive
gasoline-powered machine all they really needed was a little
knowledge and a two dollar file.
Similarly, turning compost can be an impossible, sweat-drenching,
back-wrenching chore, or it can be relatively quick and easy. It is
very difficult to drive even a very sharp shovel into a compost
pile. One needs a hay fork, something most people call a
"pitchfork." The best type for this task has a very long, delicate
handle and four, foot long, sharp, thin tines. Forks with more than
four times grab too much material. If the heap has not rotted very
thoroughly and still contains a lot of long, stringy material, a
five or six tine fork will grab too much and may require too much
strength. Spading forks with four wide-flat blades don't work well
for turning heaps, but _en extremis_ I'd prefer one to a shovel.
Also, there are shovels and then, there are shovels. Most gardeners
know the difference between a spade and a shovel. They would not try
to pick up and toss material with a spade designed only to work
straight down and loosen soil. However, did you know that there are
design differences in the shape of blade and angle of handle in
shovels. The normal "combination" shovel is made for builders to
move piles of sand or small gravel. However, use a combination
shovel to scrape up loose, fine compost that a fork won't hold and
you'll quickly have a sore back from bending over so far. Worse, the
combination shovel has a decidedly curved blade that won't scrape up
very much with each stroke.
A better choice is a flat-bladed, square-front shovel designed to
lift loose, fine-textured materials from hard surfaces. However,
even well-sharpened, these tend to stick when they bump into any
obstacle. Best is an "irrigator's shovel." This is a lightweight
tool looking like an ordinary combination shovel but with a flatter,
blunter rounded blade attached to the handle at a much sharper
angle, allowing the user to stand straighter when working. _Sharp_
irrigator's shovels are perfect for scooping up loosened soil and
tossing it to one side, for making trenches or furrows in tilled
earth and for scraping up the last bits of a compost heap being
Once turned, my long-weathered pile heats up rapidly. It is not as
hot as piles can cook, but it does steam on chilly mornings for a
few weeks. By mid-June things have cooled. The rains have also
ceased and the heap is getting dry. It has also sagged considerably.
Once more I turn the pile, watering it down with a fine mist as I do
so. This turning is much easier as the woody brassica stalks are
nearly gone. The chunks that remain as visible entities are again
put into the new pile's center; most of the bigger and
less-decomposed stuff comes from the outside of the old heap. Much
of the material has become brown to black in color and its origins
are not recognizable. The heap is now reduced to four feet high,
five feet wide, and about six feet long. Again I cover it with a
thin layer of soil and this time put a somewhat brittle, recycled
sheet of clear plastic over it to hold in the moisture and increase
the temperature. Again the pile briefly heats and then mellows
through the summer.
In September the heap is finished enough to use. It is about thirty
inches high and has been reduced to less than one-eighth of its
starting volume eighteen months ago. What compost I don't spread
during fall is protected with plastic from being leached by winter
rainfall and will be used next spring. Elapsed time: 18-24 months
from start to finish. Total effort: three turnings. Quality: very
Obviously my method is acceptable to me because the pile is not
easily visible to the residents or neighbors. It also suits a lazy
person. It is a very slow system, okay for someone who is not in a
hurry to use their compost. But few of my readers live on really
rural properties; hopefully, most of them are not as lazy as I am.
At this point I could recommend alternative, improved methods for
making compost much like cookbook recipes from which the reader
could pick and choose. There could be a small backyard recipe, the
fast recipe, the apartment recipe, the wintertime recipe, the making
compost when you can't make a pile recipes. Instead, I prefer to
compliment your intelligence and first explore the principles behind
composting. I believe that an understanding of basics will enable
you to function as a self-determined individual and adapt existing
methods, solve problems if they arise, or create something personal
and uniquely correct for your situation.
Managing living systems usually goes better when our methods imitate
nature's. Here's an example of what happens when we don't.
People who keep tropical fish in home aquariums are informed that to
avoid numerous fish diseases they must maintain sterile conditions.
Whenever the fish become ill or begin dying, the hobbyist is advised
to put antibiotics or mild antiseptics into the tank, killing off
most forms of microlife. But nature is not sterile. Nature is
Like many an apartment dweller, in my twenties I raised tropical
fish and grew house plants just to have some life around. The plants
did fine; I guess I've always had a green thumb. But growing tired
of dying fish and bacterial blooms clouding the water, I reasoned
that none of the fish I had seen in nature were diseased and their
water was usually quite clear. Perhaps the problem was that my
aquarium had an overly simplified ecology and my fish were being fed
processed, dead food when in nature the ecology was highly complex
and the fish were eating living things. So I bravely attempted the
most radical thing I could think of; I went to the country, found a
small pond and from it brought home a quart of bottom muck and pond
water that I dumped into my own aquarium. Instead of introducing
countless diseases and wiping out my fish, I actually had introduced
countless living things that began multiplying rapidly. The water
soon became crystal clear. Soon the fish were refusing to eat the
scientifically formulated food flakes I was supplying. The profuse
variety of little critters now living in the tank's gravel ate it
instead. The fish ate the critters and became perfectly healthy.
When the snails I had introduced with the pond mud became so
numerous that they covered the glass and began to obscure my view,
I'd crush a bunch of them against the wall of the aquarium and the
fish would gorge on fresh snail meat. The angelfish and guppies
especially began to look forward to my snail massacres and would
cluster around my hand when I put it into the tank. On a diet of
living things in a natural ecology even very difficult species began
Organic and biological farmers consider modern "scientific" farming
practices to be a similar situation. Instead of imitating nature's
complex stability, industrial farmers use force, attempting to bend
an unnaturally simplified ecosystem to their will. As a result, most
agricultural districts are losing soil at a non-sustainable rate and
produce food of lowered nutritional content, resulting in decreasing
health for all the life forms eating the production of our farms.
I am well aware that these condemnations may sound quite radical to
some readers. In a book this brief I cannot offer adequate support
for my concerns about soil fertility and the nation's health, but I
can refer the reader to the bibliography, where books about these
matters by writers far more sagely than I can be found. I especially
recommend the works of William Albrecht, Weston Price, Sir Robert
McCarrison, and Sir Albert Howard.
Before we ask how to compost, since nature is maximally efficient
perhaps it would benefit us to first examine how nature goes about
returning organic matter to the soil from whence it came. If we do
nearly as well, we can be proud.
Where nature is allowed to operate without human intervention, each
place develops a stable level of biomass that is inevitably the
highest amount of organic life that site could support. Whether
deciduous forest, coniferous forest, prairie, even desert, nature
makes the most of the available resources and raises the living
drama to its most intense and complex peak possible. There will be
as many mammals as there can be, as many insects, as many worms, as
many plants growing as large as they can get, as much organic matter
in all stages of decomposition and the maximum amount of relatively
stable humus in the soil. All these forms of living and decomposing
organisms are linked in one complex system; each part so closely
connected to all the others that should one be lessened or
increased, all the others change as well.
The efficient decomposition of leaves on a forest floor is a fine
example of what we might hope to achieve in a compost pile. Under
the shade of the trees and mulched thickly by leaves, the forest
floor usually stays moist. Although the leaves tend to mat where
they contact the soil, the wet, somewhat compacted layer is thin
enough to permit air to be in contact with all of the materials and
to enter the soil.
Living in this very top layer of fluffy, crumbly, moist soil mixed
with leaf material and humus, are the animals that begin the process
of humification. Many of these primary decomposers are larger,
insect-like animals commonly known to gardeners, including the wood
lice that we call pill bugs because they roll up defensively into
hard armadillo-like shells, and the highly intrusive earwigs my
daughter calls pinch bugs. There are also numerous types of insect
larvae busily at work.
A person could spend their entire life trying to understand the
ecology of a single handful of humus-rich topsoil. For a century
now, numerous soil biologists have been doing just that and still
the job is not finished. Since gardeners, much less ordinary people,
are rarely interested in observing and naming the tiny animals of
the soil, especially are we disinterested in those who do no damage
to our crops, soil animals are usually delineated only by Latin
scientific names. The variations with which soil animals live, eat,
digest, reproduce, attack, and defend themselves fills whole
sections of academic science libraries.
During the writing of this book I became quite immersed in this
subject and read far more deeply into soil biology and microbiology
than I thought I ever would. Even though this area of knowledge has
amused me, I doubt it will entertain most of you. If it does, I
recommend that you first consult specialist source materials listed
in the bibliography for an introduction to a huge universe of
I will not make you yawn by mentioning long, unfamiliar Latin names.
I will not astonish you with descriptions of complex reproductive
methods and beautiful survival strategies. Gardeners do not really
need this information. But managing the earth so that soil animals
are helped and not destroyed is essential to good gardening. And
there are a few qualities of soil animals that are found in almost
all of them. If we are aware of the general characteristics of soil
animals we can evaluate our composting and gardening practices by
their effect on these minuscule creatures.
Compared to the atmosphere, soil is a place where temperature
fluctuations are small and slow. Consequently, soil animals are
generally intolerant to sudden temperature changes and may not
function well over a very wide range. That's why leaving bare earth
exposed to the hot summer sun often retards plant growth and why
many thoughtful gardeners either put down a thin mulch in summer or
try to rapidly establish a cooling leaf canopy to shade raised beds.
Except for a few microorganisms, soil animals breathe oxygen just
like other living things and so are dependent on an adequate air
supply. Where soil is airless due to compaction, poor drainage, or
large proportions of very fine clay, soil animals are few in number.
The soil environment is generally quite moist; even when the soil
seems a little dryish the relative humidity of the soil air usually
approaches 100 percent. Soil animals consequently have not developed
the ability to conserve their body moisture and are speedily killed
by dry conditions. When faced with desiccation they retreat deeper
into the soil if there is oxygen and pore spaces large enough to
move about. So we see another reason why a thin mulch that preserves
surface moisture can greatly increase the beneficial population of
soil animals. Some single-cell animals and roundworms are capable of
surviving stress by encysting themselves, forming a little "seed"
that preserves their genetic material and enough food to reactivate
it, coming back to life when conditions improve. These cysts may
endure long periods of severe freezing and sometimes temperatures of
over 150 degree F.
Inhabitants of leaf litter reside close to the surface and so must
be able to experience exposure to dryer air and light for short
times without damage. The larger litter livers are called primary
decomposers. They spend most of their time chewing on the thick
reserve of moist leaves contacting the forest floor. Primary
decomposers are unable to digest the entire leaf. They extract only
the easily assimilable substances from their food: proteins, sugars
and other simple carbohydrates and fats. Cellulose and lignin are
the two substances that make up the hard, permanent, and woody parts
of plants; these materials cannot be digested by most soil animals.
Interestingly, just like in a cow's rumen, there are a few larvae
whose digestive tract contains cellulose-decomposing bacteria but
these larvae have little overall effect.
After the primary consumers are finished the leaves have been
mechanically disintegrated and thoroughly moistened, worked over,
chewed to tiny pieces and converted into minuscule bits of moist
excrement still containing active digestive enzymes. Many of the
bacteria and fungi that were present on the leaf surfaces have
passed through this initial digestion process alive or as spores
waiting and ready to activate. In this sense, the excrement of the
primary decomposers is not very different than manure from large
vegetarian mammals like cows and sheep although it is in much
Digestive wastes of primary decomposers are thoroughly inoculated
with microorganisms that can consume cellulose and lignin. Even
though it looks like humus, it has not yet fully decomposed. It does
have a water-retentive, granular structure that facilitates the
presence of air and moisture throughout the mass creating perfect
conditions for microbial digestion to proceed.
This excrement is also the food for a diverse group of nearly
microscopic soil animals called secondary decomposers. These are
incapable of eating anything that has not already been predigested
by the primary decomposers. The combination of microbes and the
digestive enzymes of the primary and secondary decomposers breaks
down resistant cellulose and to some degree, even lignins. The
result is a considerable amount of secondary decomposition excrement
having a much finer crumb structure than what was left by the
primary decomposers. It is closer to being humus but is still not
Now comes the final stage in humus formation. Numerous species of
earthworms eat their way through the soil, taking in a mixture of
earth, microbes, and the excrement of soil animals. All of these
substances are mixed together, ground-up, and chemically recombined
in the worm's highly active and acidic gut. Organic substances
chemically unite with soil to form clay/humus complexes that are
quite resistant to further decomposition and have an extraordinarily
high ability to hold and release the very nutrients and water that
feed plants. Earthworm casts (excrement) are mechanically very
stable and help create a durable soil structure that remains open
and friable, something gardeners and farmers call good tilth or good
crumb. Earthworms are so vitally important to soil fertility and
additionally useful as agents of compost making that an entire
section of this book will consider them in great detail.
Let's underline a composting lesson to be drawn from the forest
floor. In nature, humus formation goes on in the presence of air and
moisture. The agents of its formation are soil animals ranging in
complexity from microorganisms through insects working together in a
complex ecology. These same organisms work our compost piles and
help us change crude vegetation into humus or something close to
humus. So, when we make compost we need to make sure that there is
sufficient air and moisture.
Decomposition is actually a process of repeated digestions as
organic matter passes and repasses through the intestinal tracts of
soil animals numerous times or is attacked by the digestive enzymes
secreted by microorganisms. At each stage the vegetation and
decomposition products of that vegetation are thoroughly mixed with
animal digestive enzymes. Soil biologists have observed that where
soil conditions are hostile to soil animals, such as in compacted
fine clay soils that exclude air, organic matter is decomposed
exclusively by microorganisms. Under those conditions virtually no
decomposition-resistant humus/clay complexes form; almost everything
is consumed by the bacterial community as fuel. And the
non-productive soil is virtually devoid of organic matter.
Sir Albert Howard has been called the 'father of modern composting.'
His first composting book (1931) _The Waste Products of
Agriculture,_ stressed the vital importance of animal digestive
enzymes from fresh cow manure in making compost. When he
experimented with making compost without manure the results were
less than ideal. Most gardeners cannot obtain fresh manure but
fortunately soil animals will supply similar digestive enzymes.
Later on when we review Howard's Indore composting method we will
see how brilliantly Sir Albert understood natural decomposition and
mimicked it in a composting method that resulted in a very superior
At this point I suggest another definition for humus. Humus is the
excrement of soil animals, primarily earthworms, but including that
of some other species that, like earthworms, are capable of
combining partially decomposed organic matter and the excrement of
other soil animals with clay to create stable soil crumbs resistant
to further decomposition or consumption.
Nutrients in the Compost Pile
Some types of leaves rot much faster on the forest floor than
others. Analyzing why this happens reveals a great deal about how to
make compost piles decompose more effectively.
Leaves from leguminous (in the same botanical family as beans and
peas) trees such as acacia, carob, and alder usually become humus
within a year. So do some others like ash, cherry, and elm. More
resistant types take two years; these include oak, birch, beech, and
maple. Poplar leaves, and pine, Douglas fir, and larch needles are
very slow to decompose and may take three years or longer. Some of
these differences are due to variations in lignin content which is
highly resistant to decomposition, but speed of decomposition is
mainly influenced by the amount of protein and mineral nutrients
contained in the leaf.
Plants are composed mainly of carbohydrates like cellulose, sugar,
and lignin. The element carbon is by far the greater part of
carbohydrates [carbo(n)hydr(ogen)ates] by weight. Plants can readily
manufacture carbohydrates in large quantities because carbon and
hydrogen are derived from air (C02) and water (H2O), both substances
being available to plants in almost unlimited quantities.
Sugar, manufactured by photosynthesis, is the simplest and most
vital carbohydrate. Sugar is "burned" in all plant cells as the
primary fuel powering all living activities. Extra sugar can be more
compactly stored after being converted into starches, which are long
strings of sugar molecules linked together. Plants often have
starch-filled stems, roots, or tubers; they also make enzymes
capable of quickly converting this starch back into sugar upon
demand. We homebrewers and bakers make practical use of a similar
enzyme process to change starches stored in grains back to sugar
that yeasts can change into alcohol.
C/N of Various Tree Leaves/Needles
False acacia 14:1 Fir 48:1
Black alder 15:1 Birch 50:1
Gray alder 19:1 Beech 51:1
Ash 21:1 Maple 52:1
Birds's eye cherry 22:1 Red oak 53:1
Hornbeam 23:1 Poplar 63:1
Elm 28:1 Pine 66:1
Lime 37:1 Douglas fir 77:1
Oak 47:1 Larch 113:1
The protein content of tree leaves is very similar to their ratio of
carbon (C) compared to nitrogen (N)
Sometimes plants store food in the form of oil, the most
concentrated biological energy source. Oil is also constructed from
sugar and is usually found in seeds. Plants also build structural
materials like stem, cell walls, and other woody parts from sugars
converted into cellulose, a substance similar to starch. Very strong
structures are constructed with lignins, a material like cellulose
but much more durable. Cellulose and lignins are permanent. They
cannot be converted back into sugar by plant enzymes. Nor can most
animals or bacteria digest them.
Certain fungi can digest cellulose and lignin, as can the symbiotic
bacteria inhabiting a cow's rumen. In this respect the cow is a very
clever animal running a cellulose digestion factory in the first and
largest of its several stomachs. There, it cultures bacteria that
eat cellulose; then the cow digests the bacteria as they pass out of
one stomach and into another.
Plants also construct proteins, the vital stuff of life itself.
Proteins are mainly found in those parts of the plant involved with
reproduction and photosynthesis. Protein molecules differ from
starches and sugars in that they are larger and amazingly more
complex. Most significantly, while carbohydrates are mainly carbon
and hydrogen, proteins contain large amounts of nitrogen and
numerous other mineral nutrients.
Proteins are scarce in nature. Plants can make them only in
proportion to the amount of the nutrient, nitrogen, that they take
up from the soil. Most soils are very poorly endowed with nitrogen.
If nitrate-poor, nutrient-poor soil is well-watered there may be
lush vegetation but the plants will contain little protein and can
support few animals. But where there are high levels of nutrients in
the soil there will be large numbers of animals, even if the land is
poorly watered and grows only scrubby grasses--verdant forests
usually feed only a few shy deer while the short grass semi-desert
prairies once supported huge herds of grazing animals.
Ironically, just as it is with carbon, there is no absolute shortage
of nitrogen on Earth. The atmosphere is nearly 80 percent nitrogen.
But in the form of gas, atmospheric nitrogen is completely useless
to plants or animals. It must first be combined chemically into
forms plants can use, such as nitrate (NO3) or ammonia (NH3). These
chemicals are referred to as "fixed nitrogen."
Nitrogen gas strongly resists combining with other elements.
Chemical factories fix nitrogen only at very high temperatures and
pressures and in the presence of exotic catalysts like platinum or
by exposing nitrogen gas to powerful electric sparks. Lightning
flashes can similarly fix small amounts of nitrogen that fall to
earth dissolved in rain.
And certain soil-dwelling microorganisms are able to fix atmospheric
nitrogen. But these are abundant only where the earth is rich in
humus and minerals, especially calcium. So in a soil body where
large quantities of fixed nitrogen are naturally present, the soil
will also be well-endowed with a good supply of mineral nutrients.
Most of the world's supply of combined nitrogen is biologically
fixed at normal temperatures and standard atmospheric pressure by
soil microorganisms. We call the ones that live freely in soil
"azobacteria" and the ones that associate themselves with the roots
of legumes "rhizobia." Blue-green algae of the type that thrive in
rice paddies also manufacture nitrate nitrogen. We really don't know
how bacteria accomplish this but the nitrogen they "fix" is the
basis of most proteins on earth.
All microorganisms, including nitrogen-fixing bacteria, build their
bodies from the very same elements that plants use for growth. Where
these mineral elements are abundant in soil, the entire soil body is
more alive and carries much more biomass at all levels from bacteria
through insects, plants, and even mammals.
Should any of these vital nutrient substances be in short supply,
all biomass and plant growth will decrease to the level permitted by
the amount available, even though there is an overabundance of all
the rest. The name for this phenomena is the "Law of Limiting
Factors." The concept of limits was first formulated by a scientist,
Justus von Liebig, in the middle of the last century. Although
Liebig's name is not popular with organic gardeners and farmers
because misconceptions of his ideas have led to the widespread use
of chemical fertilizers, Liebig's theory of limits is still good
Liebig suggested imagining a barrel being filled with water as a
metaphor for plant growth: the amount of water held in the barrel
being the amount of growth. Each stave represents one of the factors
or requirements plants need in order to grow such as light, water,
oxygen, nitrogen, phosphorus, copper, boron, etc. Lowering any one
stave of the barrel, no matter which one, lessens the amount of
water that can be held and thus growth is reduced to the level of
the most limited growth factor.
For example, one essential plant protein is called chlorophyll, the
green pigment found in leaves that makes sugar through
photosynthesis. Chlorophyll is a protein containing significant
amounts of magnesium. Obviously, the plant's ability to grow is
limited by its ability to find enough fixed nitrogen and also
magnesium to make this protein.
Animals of all sizes from elephants to single cell microorganisms
are primarily composed of protein. But the greatest portion of plant
material is not protein, it is carbohydrates in one form or another.
Eating enough carbohydrates to supply their energy requirements is
rarely the survival problem faced by animals; finding enough protein
(and other vital nutrients) in their food supply to grow and
reproduce is what limits their population. The numbers and health of
grazing animals is limited by the protein and other nutrient content
of the grasses they are eating, similarly the numbers and health of
primary decomposers living on the forest floor is limited by the
nutrient content of their food. And so is the rate of decomposition.
And so too is this true in the compost pile.
The protein content of vegetation is very similar to its ratio of
carbon (C) compared to nitrogen (N). Quick laboratory analysis of
protein content is not done by measuring actual protein itself but
by measuring the amount of combined nitrogen the protein gives off
while decomposing. Acacia, alder, and leaves of other proteinaceous
legumes such as locust, mesquite, scotch broom, vetch, alfalfa,
beans, and peas have low C/N ratios because legume roots uniquely
can shelter clusters of nitrogen-fixing rhizobia. These
microorganisms can supply all the nitrate nitrogen fast-growing
legumes can use if the soil is also well endowed with other mineral
nutrients rhizobia need, especially calcium and phosphorus. Most
other plant families are entirely dependent on nitrate supplies
presented to them by the soil. Consequently, those regions or
locations with soils deficient in mineral nutrients tend to grow
coniferous forests while richer soils support forests with more
protein in their leaves. There may also be climatic conditions that
favor conifers over deciduous trees, regardless of soil fertility.
It is generally true that organic matter with a high ratio of carbon
to nitrogen also will have a high ratio of carbon to other minerals.
And low C/N materials will contain much larger amounts of other
vital mineral nutrients. When we make compost from a wide variety of
materials there are probably enough quantity and variety of
nutrients in the plant residues to form large populations of
humus-forming soil animals and microorganisms. However, when making
compost primarily with high C/N stuff we need to blend in other
substances containing sufficient fixed nitrogen and other vital
nutrient minerals. Otherwise, the decomposition process will take a
very long time because large numbers of decomposing organisms will
not be able to develop.
C/N of Compostable Materials
+/-6:1 +/-12:1 +/-25:1 +/-50:1 +/-100:1
Bone Meal Vegetables Summer grass cornstalks (dry) Sawdust
Meat scraps Garden weeds Seaweed Straw (grain) Paper
Fish waste Alfalfa hay Legume hulls Hay (low quality) Tree bark
Rabbit manure Horse manure Fruit waste Bagasse
Chicken manure Sewage sludge Hay (top quality) Grain chaff
Pig manure Silage Corn cobs
Seed meal Cow manure Cotton mill
The lists in this table of carbon/nitrogen ratios are broken out as
general ranges of C/N. It has long been an unintelligent practice of
garden-level books to state "precise" C/N ratios for materials. One
substance will be "23:1" while another will be "25:1." Such
pseudoscience is not only inaccurate but it leads readers into
similar misunderstandings about other such lists, like nitrogen
contents, or composition breakdowns of organic manures, or other
organic soil amendments. Especially misleading are those tables in
the back of many health and nutrition books spelling out the "exact"
nutrient contents of foods. There is an old saying about this:
'There are lies, then there are damned lies, and then, there are
statistics. The worse lies of all can be statistics.'
The composition of plant materials is very dependent on the level
and nature of the soil fertility that produced them. The nutrition
present in two plants of the same species, even in two samples of
the exact same variety of vegetable raised from the same packet of
seed can vary enormously depending on where the plants were grown.
William Albrecht, chairman of the Soil Department at the University
of Missouri during the 1930s, was, to the best of my knowledge, the
first mainstream scientist to thoroughly explore the differences in
the nutritional qualities of plants and to identify specific aspects
of soil fertility as the reason why one plant can be much more
nutritious than another and why animals can be so much healthier on
one farm compared to another. By implication, Albrecht also meant to
show the reason why one nation of people can be much less healthy
than another. Because his holistic outlook ran counter to powerful
vested interests of his era, Albrecht was professionally scorned and
ultimately left the university community, spending the rest of his
life educating the general public, especially farmers and health
Summarized in one paragraph, Albrecht showed that within a single
species or variety, plant protein levels vary 25 percent or more
depending on soil fertility, while a plant's content of vital
nutrients like calcium, magnesium, and phosphorus can simultaneously
move up or down as much as 300 percent, usually corresponding to
similar changes in its protein level. Albrecht also discovered how
to manage soil in order to produce highly nutritious food. Chapter
Eight has a lot more praise for Dr. Albrecht. There I explore this
interesting aspect of gardening in more detail because how we make
and use organic matter has a great deal to do with the resulting
nutritional quality of the food we grow.
Imagine trying to make compost from deficient materials such as a
heap of pure, moist sawdust. What happens? Very little and very,
very slowly. Trees locate most of their nutrient accumulation in
their leaves to make protein for photosynthesis. A small amount goes
into making bark. Wood itself is virtually pure cellulose, derived
from air and water. If, when we farmed trees, we removed only the
wood and left the leaves and bark on the site, we would be removing
next to nothing from the soil. If the sawdust comes from a lumber
mill, as opposed to a cabinet shop, it may also contain some bark
and consequently small amounts of other essential nutrients.
Thoroughly moistened and heaped up, a sawdust pile would not heat
up, only a few primary decomposers would take up residence. A person
could wait five years for compost to form from pure moist sawdust
and still not much would happen. Perhaps that's why the words
"compost" and "compot" as the British mean it, are connected. In
England, a compot is a slightly fermented mixture of many things
like fruits. If we mixed the sawdust with other materials having a
very low C/N, then it would decompose, along with the other items.
Practical Compost Making
To make compost rot rapidly you need to achieve a strong and lasting
rise in temperature. Cold piles will eventually decompose and humus
will eventually form but, without heat, the process can take a long,
long time. Getting a pile to heat up promptly and stay hot requires
the right mixture of materials and a sensible handling of the pile's
air and moisture supply.
Compost piles come with some built-in obstacles. The intense heat
and biological activity make a heap slump into an airless mass, yet
if composting is to continue the pile must allow its living
inhabitants sufficient air to breath. Hot piles tend to dry out
rapidly, but must be kept moist or they stop working. But heat is
desirable and watering cools a pile down. If understood and managed,
these difficulties are really quite minor.
Composting is usually an inoffensive activity, but if done
incorrectly there can be problems with odor and flies. This chapter
will show you how to make nuisance-free compost.
The main difference between composting in heaps and natural
decomposition on the earth's surface is temperature. On the forest
floor, leaves leisurely decay and the primary agents of
decomposition are soil animals. Bacteria and other microorganisms
are secondary. In a compost pile the opposite occurs: we substitute
a violent fermentation by microorganisms such as bacteria and fungi.
Soil animals are secondary and come into play only after the
microbes have had their hour.
Under decent conditions, with a relatively unlimited food supply,
bacteria, yeasts, and fungi can double their numbers every twenty to
thirty minutes, increasing geometrically: 1, 2, 4, 8, 16, 32, 64,
128, 256, 512, 1,024, 2,048, 4,096, etc. In only four hours one cell
multiplies to over four thousand. In three more hours there will be
For food, they consume the compost heap. Almost all oxygen-breathing
organisms make energy by "burning" some form of organic matter as
fuel much like gasoline powers an automobile. This cellular burning
does not happen violently with flame and light. Living things use
enzymes to break complex organic molecules down into simpler ones
like sugar (and others) and then enzymatically unite these with
oxygen. But as gentle as enzymatic combustion may seem, it still is
burning. Microbes can "burn" starches, cellulose, lignin, proteins,
and fats, as well as sugars.
No engine is one hundred percent efficient. All motors give off
waste heat as they run. Similarly, no plant or animal is capable of
using every bit of energy released from their food, and consequently
radiate heat. When working hard, living things give off more heat;
when resting, less. The ebb and flow of heat production matches
their oxygen consumption, and matches their physical and metabolic
activities, and growth rates. Even single-celled animals like
bacteria and fungi breathe oxygen and give off heat.
Soil animals and microorganisms working over the thin layer of leaf
litter on the forest floor also generate heat but it dissipates
without making any perceptible increase in temperature. However,
compostable materials do not transfer heat readily. In the language
of architecture and home building they might be said to have a high
"R" value or to be good insulators When a large quantity of
decomposing materials are heaped up, biological heat is trapped
within the pile and temperature increases, further accelerating the
rate of decomposition.
Temperature controls how rapidly living things carry out their
activities. Only birds and mammals are warm blooded-capable of
holding the rate of their metabolic chemistry constant by holding
their body temperature steady. Most animals and all microorganisms
have no ability to regulate their internal temperature; when they
are cold they are sluggish, when warm, active. Driven by
cold-blooded soil animals and microorganisms, the hotter the compost
pile gets the faster it is consumed.
This relationship between temperature and the speed of biological
activity also holds true for organic chemical reactions in a
test-tube, the shelf-life of garden seed, the time it takes seed to
germinate and the storage of food in the refrigerator. At the
temperature of frozen water most living chemical processes come to a
halt or close to it. That is why freezing prevents food from going
through those normal enzymatic decomposition stages we call
By the time that temperature has increased to about 50 degree F, the
chemistry of most living things is beginning to operate efficiently.
From that temperature the speed of organic chemical reactions then
approximately doubles with each 20 degree increase of temperature.
So, at 70 degree F decomposition is running at twice the rate it
does at 50 degree, while at 90 degree four times as rapidly as at 50
degree and so on. However, when temperatures get to about 150 degree
organic chemistry is not necessarily racing 32 times as fast as
compared to 50 degree because many reactions engendered by living
things decline in efficiency at temperatures much over 110 degree.
This explanation is oversimplified and the numbers I have used to
illustrate the process are slightly inaccurate, however the idea
itself is substantially correct. You should understand that while
inorganic chemical reactions accelerate with increases in
temperature almost without limit, those processes conducted by
living things usually have a much lower terminal temperature. Above
some point, life stops. Even the most heat tolerant soil animals
will die or exit a compost pile by the time the temperature exceeds
120 degree, leaving the material in the sole possession of
Most microorganisms cannot withstand temperatures much over 130
degree. When the core of a pile heats beyond this point they either
form spores while waiting for things to cool off, or die off. Plenty
of living organisms will still be waiting in the cooler outer layers
of the heap to reoccupy the core once things cool down. However,
there are unique bacteria and fungi that only work effectively at
temperatures exceeding 110 degree. Soil scientists and other
academics that sometimes seem to measure their stature on how well
they can baffle the average person by using unfamiliar words for
ordinary notions call these types of organisms _thermophiles,_ a
Latin word that simply means "heat lovers."
Compost piles can get remarkably hot. Since thermophilic
microorganisms and fungi generate the very heat they require to
accelerate their activities and as the ambient temperature increases
generate even more heat, the ultimate temperature is reached when
the pile gets so hot that even thermophilic organisms begin to die
off. Compost piles have exceeded 160 degree. You should expect the
heaps you build to exceed 140 degree and shouldn't be surprised if
they approach 150 degree
Other types of decomposing organic matter can get even hotter. For
example, haystacks commonly catch on fire because dry hay is such an
excellent insulator. If the bales in the center of a large hay stack
are just moist enough to encourage rapid bacterial decomposition,
the heat generated may increase until dryer bales on the outside
begin to smoke and then burn. Wise farmers make sure their hay is
thoroughly dry before baling and stacking it.
How hot the pile can get depends on how well the composter controls
a number of factors. These are so important that they need to be
considered in detail.
_Particle size. _Microorganisms are not capable of chewing or
mechanically attacking food. Their primary method of eating is to
secrete digestive enzymes that break down and then dissolve organic
matter. Some larger single-cell creatures can surround or envelop
and then "swallow" tiny food particles. Once inside the cell this
material is then attacked by similar digestive enzymes.
Since digestive enzymes attack only outside surfaces, the greater
the surface area the composting materials present the more rapidly
microorganisms multiply to consume the food supply. And the more
heat is created. As particle size decreases, the amount of surface
area goes up just about as rapidly as the number series used a few
paragraphs back to illustrate the multiplication of microorganisms.
The surfaces presented in different types of soil similarly affect
plant growth so scientists have carefully calculated the amount of
surface areas of soil materials. Although compost heaps are made of
much larger particles than soil, the relationship between particle
size and surface area is the same. Clearly, when a small difference
in particle size can change the amount of surface area by hundreds
of times, reducing the size of the stuff in the compost pile will:
- expose more material to digestive enzymes;
- greatly accelerate decomposition;
- build much higher temperatures.
_Oxygen supply. _All desirable organisms of decomposition are oxygen
breathers or "aerobes. There must be an adequate movement of air
through the pile to supply their needs. If air supply is choked off,
aerobic microorganisms die off and are replaced by anaerobic
organisms. These do not run by burning carbohydrates, but derive
energy from other kinds of chemical reactions not requiring oxygen.
Anaerobic chemistry is slow and does not generate much heat, so a
pile that suddenly cools off is giving a strong indication that the
core may lack air. The primary waste products of aerobes are water
and carbon dioxide gas--inoffensive substances. When most people
think of putrefaction they are actually picturing decomposition by
anaerobic bacteria. With insufficient oxygen, foul-smelling
materials are created. Instead of humus being formed, black, tarlike
substances develop that are much less useful in soil. Under airless
conditions much nitrate is permanently lost. The odiferous wastes of
anaerobes also includes hydrogen sulfide (smells like rotten eggs),
as well as other toxic substances with very unpleasant qualities.
Heaps built with significant amounts of coarse, strong, irregular
materials tend to retain large pore spaces, encourage airflow and
remain aerobic. Heat generated in the pile causes hot air in the
pile's center to rise and exit the pile by convection. This
automatically draws in a supply of fresh, cool air. But heaps made
exclusively of large particles not only present little surface area
to microorganisms, they permit so much airflow that they are rapidly
cooled. This is one reason that a wet firewood rick or a pile of
damp wood chips does not heat up. At the opposite extreme, piles
made of finely ground or soft, wet materials tend to compact, ending
convective air exchanges and bringing aerobic decomposition to a
halt. In the center of an airless heap, anaerobic organisms
immediately take over.
Surface Area of One Gram of Soil Particles
Particle Size Diameter of Number of Surface Area
Particles in mm Particles per gm per square cm
Very Coarse Sand 2.00-1.00 90 11
Coarse Sand 1.00-0.50 720 23
Medium Sand 0.50-0.25 5,700 45
Find Sand 0.25-0.10 46,000 91
Very Fine Sand 0.10-005 772,000 227
Silt 0.05-0.002 5,776,000 454
Composters use several strategies to maintain airflow. The most
basic one is to blend an assortment of components so that coarse,
stiff materials maintain a loose texture while soft, flexible stuff
tends to partially fill in the spaces. However, even if the heap
starts out fluffy enough to permit adequate airflow, as the
materials decompose they soften and tend to slump together into an
Periodically turning the pile, tearing it apart with a fork and
restacking it, will reestablish a looser texture and temporarily
recharge the pore spaces with fresh air. Since the outer surfaces of
a compost pile do not get hot, tend to completely dry out, and fail
to decompose, turning the pile also rotates the unrotted skin to the
core and then insulates it with more-decomposed material taken from
the center of the original pile. A heap that has cooled because it
has gone anaerobic can be quickly remedied by turning.
Piles can also be constructed with a base layer of fine sticks,
smaller tree prunings, and dry brushy material. This porous base
tends to enhance the inflow of air from beneath the pile. One
powerful aeration technique is to build the pile atop a low platform
made of slats or strong hardware cloth.
Larger piles can have air channels built into them much as light
wells and courtyards illuminate inner rooms of tall buildings. As
the pile is being constructed, vertical heavy wooden fence posts, 4
x 4's, or large-diameter plastic pipes with numerous quarter-inch
holes drilled in them are spaced every three or four feet. Once the
pile has been formed and begins to heat, the wooden posts are
wiggled around and then lifted out, making a slightly conical airway
from top to bottom. Perforated plastic vent pipes can be left in the
heap. With the help of these airways, no part of the pile is more
than a couple of feet from oxygen
_Moisture. _A dry pile is a cold pile. Microorganisms live in thin
films of water that adhere to organic matter whereas fungi only grow
in humid conditions; if the pile becomes dry, both bacteria and
fungi die off. The upwelling of heated air exiting the pile tends to
rapidly dehydrate the compost heap. It usually is necessary to
periodically add water to a hot working heap. Unfortunately,
remoistening a pile is not always simple. The nature of the
materials tends to cause water to be shed and run off much like a
thatched roof protects a cottage.
Since piles tend to compact and dry out at the same time, when they
are turned they can simultaneously be rehydrated. When I fork over a
heap I take brief breaks and spray water over the new pile, layer by
layer. Two or three such turnings and waterings will result in
The other extreme can also be an obstacle to efficient composting.
Making a pile too wet can encourage soft materials to lose all
mechanical strength, the pile immediately slumps into a chilled,
airless mass. Having large quantities of water pass through a pile
can also leach out vital nutrients that feed organisms of
decomposition and later on, feed the garden itself. I cover my heaps
with old plastic sheeting from November through March to protect
them from Oregon's rainy winter climate.
Understanding how much moisture to put into a pile soon becomes an
intuitive certainty. Beginners can gauge moisture content by
squeezing a handful of material very hard. It should feel very damp
but only a few drops of moisture should be extractable. Industrial
composters, who can afford scientific guidance to optimize their
activities, try to establish and maintain a laboratory-measured
moisture content of 50 to 60 percent by weight. When building a
pile, keep in mind that certain materials like fresh grass clippings
and vegetable trimmings already contain close to 90 percent moisture
while dry components such as sawdust and straw may contain only 10
percent and resist absorbing water at that. But, by thoroughly
mixing wet and dry materials the overall moisture content will
_Size of the pile._ It is much harder to keep a small object hot
than a large one. That's because the ratio of surface area to volume
goes down as volume goes up. No matter how well other factors
encourage thermophiles, it is still difficult to make a pile heat up
that is less than three feet high and three feet in diameter. And a
tiny pile like that one tends to heat only for a short time and then
cool off rapidly. Larger piles tend to heat much faster and remain
hot long enough to allow significant decomposition to occur. Most
composters consider a four foot cube to be a minimum practical size.
Industrial or municipal composters build windrows up to ten feet at
the base, seven feet high, and as long as they want.
However, even if you have unlimited material there is still a limit
to the heap's size and that limiting factor is air supply. The
bigger the compost pile the harder it becomes to get oxygen into the
center. Industrial composters may have power equipment that
simultaneously turns and sprays water, mechanically oxygenating and
remoistening a massive windrow every few days. Even poorly-financed
municipal composting systems have tractors with scoop loaders to
turn their piles frequently. At home the practical limit is probably
a heap six or seven feet wide at the base, initially about five feet
high (it will rapidly slump a foot or so once heating begins), and
as long as one has material for.
Though we might like to make our compost piles so large that
maintaining sufficient airflow becomes the major problem we face,
the home composter rarely has enough materials on hand to build a
huge heap all at once. A single lawn mowing doesn't supply that many
clippings; my own kitchen compost bucket is larger and fills faster
than anyone else's I know of but still only amounts to a few gallons
a week except during August when we're making jam, canning
vegetables, and juicing. Garden weeds are collected a wheelbarrow at
a time. Leaves are seasonal. In the East the annual vegetable garden
clean-up happens after the fall frost. So almost inevitably, you
will be building a heap gradually.
That's probably why most garden books illustrate compost heaps as
though they were layer cakes: a base layer of brush, twigs, and
coarse stuff to allow air to enter, then alternating thin layers of
grass clippings, leaves, weeds, garbage, grass, weeds, garbage, and
a sprinkling of soil, repeated until the heap is five feet tall. It
can take months to build a compost pile this way because heating and
decomposition begin before the pile is finished and it sags as it is
built. I recommend several practices when gradually forming a heap.
Keep a large stack of dry, coarse vegetation next to a building
pile. As kitchen garbage, grass clippings, fresh manure or other wet
materials come available the can be covered with and mixed into this
dry material. The wetter, greener items will rehydrate the dry
vegetation and usually contain more nitrogen that balances out the
higher carbon of dried grass, tall weeds, and hay.
If building the heap has taken several months, the lower central
area will probably be well on its way to becoming compost and much
of the pile may have already dried out by the time it is fully
formed. So the best time make the first turn and remoisten a
long-building pile is right after it has been completed.
Instead of picturing a layer cake, you will be better off comparing
composting to making bread. Flour, yeast, water, molasses, sunflower
seeds, and oil aren't layered, they're thoroughly blended and then
kneaded and worked together so that the yeast can interact with the
other materials and bring about a miraculous chemistry that we call
_Carbon to nitrogen ratio._ C/N is the most important single aspect
that controls both the heap's ability to heat up and the quality of
the compost that results. Piles composed primarily of materials with
a high ratio of carbon to nitrogen do not get very hot or stay hot
long enough. Piles made from materials with too low a C/N get too
hot, lose a great deal of nitrogen and may "burn out."
The compost process generally works best when the heap's starting
C/N is around 25:1. If sawdust, straw, or woody hay form the bulk of
the pile, it is hard to bring the C/N down enough with just grass
clippings and kitchen garbage. Heaps made essentially of high C/N
materials need significant additions of the most potent manures
and/or highly concentrated organic nitrogen sources like seed meals
or slaughterhouse concentrates. The next chapter discusses the
nature and properties of materials used for composting in great
I have already stressed that filling this book with tables listing
so-called precise amounts of C/N for compostable materials would be
foolish. Even more wasteful of energy would be the composter's
attempt to compute the ratio of carbon to nitrogen resulting from
any mixture of materials. For those who are interested, the sidebar
provides an illustration of how that might be done.
Here's a simple arithmetic problem that illustrates how to balance
carbon to nitrogen.
_QUESTION:_ I have 100 pounds of straw with a C/N of 66:1, how much
chicken manure (C/N of 8:1) do I have to add to bring the total to
an average C/N of 25:1.
_ANSWER:_ There is 1 pound of nitrogen already in each 66 pounds of
straw, so there are already about 1.5 pounds of N in 100 pounds of
straw. 100 pounds of straw-compost at 25:1 would have about 4 pounds
of nitrogen, so I need to add about 2.5 more pounds of N. Eight
pounds of chicken manure contain 1 pound of N; 16 pounds have 2. So,
if I add 32 pounds of chicken manure to 100 pounds of straw, I will
have 132 pounds of material containing about 5.5 pounds of N, a C/N
of 132:5.5 or about 24:1.
It is far more sensible to learn from experience. Gauge the
proportions of materials going into a heap by the result. If the
pile gets really hot and stays that way for a few weeks before
gradually cooling down then the C/N was more or less right. If,
after several turnings and reheatings, the material has not
thoroughly decomposed, then the initial C/N was probably too high.
The words "thoroughly decomposed" mean here that there are no
recognizable traces of the original materials in the heap and the
compost is dark brown to black, crumbly, sweet smelling and most
importantly, _when worked into soil it provokes a marked growth
response, similar to fertilizer._
If the pile did not initially heat very much or the heating stage
was very brief, then the pile probably lacked nitrogen. The solution
for a nitrogen-deficient pile is to turn it, simultaneously blending
in more nutrient-rich materials and probably a bit of water too.
After a few piles have been made novice composters will begin to get
the same feel for their materials as bakers have for their flour,
shortening, and yeast.
It is also possible to err on the opposite end of the scale and make
a pile with too much nitrogen. This heap will heat very rapidly,
become as hot as the microbial population can tolerate, lose
moisture very quickly, and probably smell of ammonia, indicating
that valuable fixed nitrogen is escaping into the atmosphere. When
proteins decompose their nitrogen content is normally released as
ammonia gas. Most people have smelled small piles of spring grass
clippings doing this very thing. Ammonia is always created when
proteins decompose in any heap at any C/N. But a properly made
compost pile does not permit this valuable nitrogen source to
There are other bacteria commonly found in soil that uptake ammonia
gas and change it to the nitrates that plants and soil life forms
need to make other proteins. These nitrification microorganisms are
extremely efficient at reasonable temperatures but cannot survive
the extreme high temperatures that a really hot pile can achieve.
They also live only in soil. That is why it is very important to
ensure that about 10 percent of a compost pile is soil and to coat
the outside of a pile with a frosting of rich earth that is kept
damp. One other aspect of soil helps prevent ammonia loss. Clay is
capable of attracting and temporarily holding on to ammonia until it
is nitrified by microorganisms. Most soils contain significant
amounts of clay.
The widespread presence of clay and ammonia-fixing bacteria in all
soils permits industrial farmers to inject gaseous ammonia directly
into the earth where it is promptly and completely altered into
nitrates. A very hot pile leaking ammonia may contain too little
soil, but more likely it is also so hot that the nitrifying bacteria
have been killed off. Escaping ammonia is not only an offensive
nuisance, valuable fertility is being lost into the atmosphere.
_Weather and season. _You can adopt a number of strategies to keep
weather from chilling a compost pile. Wind both lowers temperature
and dries out a pile, so if at all possible, make compost in a
sheltered location. Heavy, cold rains can chill and waterlog a pile.
Composting under a roof will also keep hot sun from baking moisture
out of a pile in summer. Using bins or other compost structures can
hold in heat that might otherwise be lost from the sides of
It is much easier to maintain a high core temperature when the
weather is warm. It may not be so easy to make hot compost heaps
during a northern winter. So in some parts of the country I would
not expect too much from a compost pile made from autumn cleanup.
This stack of leaves and frost-bitten garden plants may have to
await the spring thaw, then to be mixed with potent spring grass
clippings and other nitrogenous materials in order to heat up and
complete the composting process. What to do with kitchen garbage
during winter in the frozen North makes an interesting problem and
leads serious recyclers to take notice of vermicomposting. (See
In southern regions the heap may be prevented from overheating by
making it smaller or not as tall. Chapter Nine describes in great
detail how Sir Albert Howard handled the problem of high air
temperature while making compost in India.
The Fertilizing Value of Compost
It is not possible for me to tell you how well your own homemade
compost will fertilize plants. Like home-brewed beer and home-baked
bread you can be certain that your compost may be the equal of or
superior to almost any commercially made product and certainly will
be better fertilizer than the high carbon result of municipal solid
waste composting. But first, let's consider two semi-philosophical
questions, "good for what?" and "poor as what?"
Any compost is a "social good" if it conserves energy, saves space
in landfills and returns some nutrients and organic matter to the
soil, whether for lawns, ornamental plantings, or vegetable gardens.
Compared to the fertilizer you would have purchased in its place,
any homemade compost will be a financial gain unless you buy
expensive motor-powered grinding equipment to produce only small
Making compost is also a "personal good." For a few hours a year,
composting gets you outside with a manure fork in your hand, working
up a sweat. You intentionally participate in a natural cycle: the
endless rotation of carbon from air to organic matter in the form of
plants, to animals, and finally all of it back into soil. You can
observe the miraculous increase in plant and soil health that
happens when you intensify and enrich that cycle of carbon on land
under your control.
So any compost is good compost. But will it be good fertilizer?
Answering that question is a lot harder: it depends on so many
factors. The growth response you'll get from compost depends on what
went into the heap, on how much nitrate nitrogen was lost as ammonia
during decomposition, on how completely decomposition was allowed to
proceed, and how much nitrate nitrogen was created by microbes
The growth response from compost also depends on the soil's
temperature. Just like every other biological process, the nutrients
in compost only GROW the plant when they decompose in the soil and
are released. Where summer is hot, where the average of day and
night temperatures are high, where soil temperatures reach 80 degree
for much of the frost-free season, organic matter rots really fast
and a little compost of average quality makes a huge increase in
plant growth. Where summer is cool and soil organic matter
decomposes slowly, poorer grades of compost have little immediate
effect, or worse, may temporarily interfere with plant growth.
Hotter soils are probably more desperate for organic matter and may
give you a marked growth response from even poor quality compost;
soils in cool climates naturally contain higher quantities of humus
and need to be stoked with more potent materials if high levels of
nutrients are to be released.
Compost is also reputed to make enormous improvements in the
workability, or tilth of the soil. This aspect of gardening is so
important and so widely misunderstood, especially by organic
gardeners, that most of Chapter Seven is devoted to considering the
roles of humus in the soil.
GROWing the plant
One of the things I enjoy most while gardening is GROWing some of my
plants. I don't GROW them all because there is no point in having
giant parsley or making the corn patch get one foot taller. Making
everything get as large as possible wouldn't result in maximum
nutrition either. But just for fun, how about a 100-plus-pound
pumpkin? A twenty-pound savoy cabbage? A cauliflower sixteen inches
in diameter? An eight-inch diameter beet? Now that's GROWing!
Here's how. Simply remove as many growth limiters as possible and
watch the plant's own efforts take over. One of the best examples
I've ever seen of how this works was in a neighbor's backyard
greenhouse. This retired welder liked his liquor. Having more time
than money and little respect for legal absurdities, he had
constructed a small stainless steel pot still, fermented his own
mash, and made a harsh, hangover-producing whiskey from grain and
cane sugar that Appalachians call "popskull." To encourage rapid
fermentation, his mashing barrel was kept in the warm greenhouse.
The bubbling brew gave off large quantities of carbon dioxide gas.
The rest of his greenhouse was filled with green herbs that flowered
fragrantly in September. Most of them were four or five feet tall
but those plants on the end housing the mash barrel were seven feet
tall and twice as bushy. Why? Because the normal level of
atmospheric CO2 actually limits plant growth.
We can't increase the carbon supply outdoors. But we can loosen the
soil eighteen to twenty-four inches down (or more for deeply-rooting
species) in an area as large as the plant's root system could
possibly ramify during its entire growing season. I've seen some
GROWers dig holes four feet deep and five feet in diameter for
individual plants. We can use well-finished, strong compost to
increase the humus content of that soil, and supplement that with
manure tea or liquid fertilizer to provide all the nutrients the
plant could possibly use. We can allocate only one plant to that
space and make sure absolutely no competition develops in that space
for light, water, or nutrients. We can keep the soil moist at all
times. By locating the plant against a reflective white wall we can
increase its light levels and perhaps the nighttime temperatures
(plants make food during the day and use it to grow with at night).
Textural improvements from compost depend greatly on soil type.
Sandy and loamy soils naturally remain open and workable and sustain
good tilth with surprisingly small amounts of organic matter. Two or
three hundred pounds (dry weight) of compost per thousand square
feet per year will keep coarse-textured soils in wonderful physical
condition. This small amount of humus is also sufficient to
encourage the development of a lush soil ecology that creates the
natural health of plants.
Silty soils, especially ones with more clay content, tend to become
compacted and when low in humus will crust over and puddle when it
rains hard. These may need a little more compost, perhaps in the
range of three to five hundred pounds per thousand square feet per
Clay soils on the other hand are heavy and airless, easily
compacted, hard to work, and hard to keep workable. The mechanical
properties of clay soils greatly benefit from additions of organic
matter several times larger than what soils composed of larger
particles need. Given adequate organic matter, even a heavy clay can
be made to behave somewhat like a rich loam does.
Perhaps you've noticed that I've still avoided answering the
question, "how good is your compost?" First, lets take a look at
laboratory analyses of various kinds of compost, connect that to
what they were made from and that to the kind of growing results one
might get from them. I apologize that despite considerable research
I was unable to discover more detailed breakdowns from more
composting activities. But the data I do have is sufficient to
appreciate the range of possibilities.
Considered as a fertilizer to GROW plants, Municipal Solid Waste
(MSW) compost is the lowest grade material I know of. It is usually
broadcast as a surface mulch. The ingredients municipal composters
must process include an indiscriminate mixture of all sorts of urban
organic waste: paper, kitchen garbage, leaves, chipped tree
trimmings, commercial organic garbage like restaurant waste, cannery
wastes, etc. Unfortunately, paper comprises the largest single
ingredient and it is by nature highly resistant to decomposition.
MSW composting is essentially a recycling process, so no soil, no
manure and no special low C/N sources are used to improve the
fertilizing value of the finished product.
Municipal composting schemes usually must process huge volumes of
material on very valuable land close to cities. Economics mean the
heaps are made as large as possible, run as fast as possible, and
gotten off the field without concern for developing their highest
qualities. Since it takes a long time to reduce large proportions of
carbon, especially when they are in very decomposition-resistant
forms like paper, and since the use of soil in the compost heap is
essential to prevent nitrate loss, municipal composts tend to be low
in nitrogen and high in carbon. By comparison, the poorest home
garden compost I could find test results for was about equal to the
best municipal compost. The best garden sample ("B") is pretty fine
stuff. I could not discover the ingredients that went into either
garden compost but my supposition is that gardener "A" incorporated
large quantities of high C/N materials like straw, sawdust and the
like while gardener "B" used manure, fresh vegetation, grass
clippings and other similar low C/N materials. The next chapter will
evaluate the suitability of materials commonly used to make compost.
Analyses of Various Composts
Source N% P% K% Ca% C/N
Vegetable trimmings & paper 1.57 0.40 0.40 24:1
Municipal refuse 0.97 0.16 0.21 24:1
Johnson City refuse 0.91 0.22 0.91 1.91 36:1
Gainsville, FL refuse 0.57 0.26 0.22 1.88 ?
Garden compost "A" 1.40 0.30 0.40 25:1
Garden compost "B" 3.50 1.00 2.00 10:1
To interpret this chart, let's make as our standard of comparison
the actual gardening results from some very potent organic material
I and probably many of my readers have probably used: bagged chicken
manure compost. The most potent I've ever purchased is inexpensively
sold in one-cubic-foot plastic sacks stacked up in front of my local
supermarket every spring. The sacks are labeled 4-3-2. I've
successfully grown quite a few huge, handsome, and healthy
vegetables with this product. I've also tried other similar sorts
also labeled "chicken manure compost" that are about half as potent.
From many years of successful use I know that 15 to 20 sacks (about
300-400 dry-weight pounds) of 4-3-2 chicken compost spread and
tilled into one thousand square feet will grow a magnificent garden.
Most certainly a similar amount of the high analysis Garden "B"
compost would do about the same job. Would three times as much less
potent compost from Garden "A" or five times as much even poorer
stuff from the Johnson City municipal composting operation do as
well? Not at all! Neither would three times as many sacks of dried
steer manure. Here's why.
If composted organic matter is spread like mulch atop the ground on
lawns or around ornamentals and allowed to remain there its nitrogen
content and C/N are not especially important. Even if the C/N is
still high soil animals will continue the job of decomposition much
as happens on the forest floor. Eventually their excrement will be
transported into the soil by earthworms. By that time the C/N will
equal that of other soil humus and no disruption will occur to the
Growing vegetables is much more demanding than growing most
perennial ornamentals or lawns. Excuse me, flower gardeners, but
I've observed that even most flowers will thrive if only slight
improvements are made in their soil. The same is true for most
herbs. Difficulties with ornamentals or herbs are usually caused by
attempting to grow a species that is not particularly well-adapted
to the site or climate. Fertilized with sacked steer manure or
mulched with average-to-poor compost, most ornamentals will grow
But vegetables are delicate, pampered critters that must grow as
rapidly as they can grow if they are to be succulent, tasty, and
yield heavily. Most of them demand very high levels of available
nutrients as well as soft, friable soil containing reasonable levels
of organic matter. So it is extremely important that a vegetable
gardener understand the inevitable disruption occurring when organic
matter that has a C/N is much above 12:1 is tilled into soil.
Organic matter that has been in soil for a while has been altered
into a much studied substance, humus. We know for example that humus
always has a carbon to nitrogen ratio of from 10:1 to about 12:1,
just like compost from Garden "B." Garden writers call great compost
like this, "stable humus," because it is slow to decompose. Its
presence in soil steadily feeds a healthy ecology of microorganisms
important to plant health, and whose activity accelerates release of
plant nutrients from undecomposed rock particles. Humus is also
fertilizer because its gradual decomposition provides mineral
nutrients that make plants grow. The most important of these
nutrients is nitrate nitrogen, thus soil scientists may call humus
When organic material with a C/N below 12:1 is mixed into soil its
breakdown is very rapid. Because it contains more nitrogen than
stable humus does, nitrogen is rapidly released to feed the plants
and soil life. Along with nitrogen comes other plant nutrients. This
accelerated nitrification continues until the remaining nitrogen
balances with the remaining carbon at a ratio of about 12:1. Then
the soil returns to equilibrium. The lower the C/N the more rapid
the release, and the more violent the reaction in the soil. Most low
C/N organic materials, like seed meal or chicken manure, rapidly
release nutrients for a month or two before stabilizing. What has
been described here is fertilizer.
When organic material with a C/N higher than 12:1 is tilled into
soil, soil animals and microorganisms find themselves with an
unsurpassed carbohydrate banquet. Just as in a compost heap, within
days bacteria and fungi can multiply to match any food supply. But
to construct their bodies these microorganisms need the same
nutrients that plants need to grow--nitrogen, potassium, phosphorus,
calcium, magnesium, etc. There are never enough of these nutrients
in high C/N organic matter to match the needs of soil bacteria,
especially never enough nitrogen, so soil microorganisms uptake
these nutrients from the soil's reserves while they "bloom" and
rapidly consume all the new carbon presented to them.
During this period of rapid decomposition the soil is thoroughly
robbed of plant nutrients. And nitrification stops. Initially, a
great deal of carbon dioxide gas may be given off, as carbon is
metabolically "burned." However, CO2 in high concentrations can be
toxic to sprouting seeds and consequently, germination failures may
occur. When I was in the seed business I'd get a few complaints
every year from irate gardeners demanding to know why every seed
packet they sowed failed to come up well. There were two usual
causes. Either before sowing all the seeds were exposed to
temperatures above 110 degree or more likely, a large quantity of
high C/N "manure" was tilled into the garden just before sowing. In
soil so disturbed transplants may also fail to grow for awhile. If
the "manure" contains a large quantity of sawdust the soil will seem
very infertile for a month or three.
Sir Albert Howard had a unique and pithy way of expressing this
reality. He said that soil was not capable of working two jobs at
once. You could not expect it to nitrify humus while it was also
being required to digest organic matter. That's one reason he
thought composting was such a valuable process. The digestion of
organic matter proceeds outside the soil; when finished product,
humus, is ready for nitrification, it is tilled in.
Rapid consumption of carbon continues until the C/N of the new
material drops to the range of stable humus. Then decay
microorganisms die off and the nutrients they hoarded are released
back into the soil. How long the soil remains inhospitable to plant
growth and seed germination depends on soil temperature, the amount
of the material and how high its C/N is, and the amount of nutrients
the soil is holding in reserve. The warmer and more fertile the soil
was before the addition of high C/N organic matter, the faster it
Judging by the compost analyses in the table, I can see why some
municipalities are having difficulty disposing of the solid waste
compost they are making. One governmental composting operation that
does succeed in selling everything they can produce is Lane County,
Oregon. Their _yard waste compost_ is eagerly paid for by local
gardeners. Lane County compost is made only from autumn leaves,
grass clippings, and other yard wastes. No paper!
Yard waste compost is a product much like a homeowner would produce.
And yard waste compost contains no industrial waste or any material
that might pose health threats. All woody materials are finely
chipped before composting and comprise no more than 20 percent of
the total undecayed mass by weight. Although no nutrient analysis
has been done by the county other than testing for pH (around 7.0)
and, because of the use of weed and feed fertilizers on lawns, for
2-4D (no residual trace ever found present), I estimate that the
overall C/N of the materials going into the windrows at 25:1. I
wouldn't be surprised if the finished compost has a C/N close to
Incidentally, Lane County understands that many gardeners don't have
pickup trucks. They reasonably offer to deliver their compost for a
small fee if at least one yard is purchased. Other local governments
also make and deliver yard waste compost.
So what about your own home compost? If you are a flower,
ornamental, or lawn grower, you have nothing to worry about. Just
compost everything you have available and use all you wish to make.
If tilling your compost into soil seems to slow the growth of
plants, then mulch with it and avoid tilling it in, or adjust the
C/N down by adding fertilizers like seed meal when tilling it in.
If you are a vegetable gardener and your compost doesn't seem to
provoke the kind of growth response you hoped for, either shallowly
till in compost in the fall for next year's planting, by which time
it will have become stable humus, or read further. The second half
of this book contains numerous hints about how to make potent
compost and about how to use complete organic fertilizers in
combination with compost to grow the lushest garden imaginable.
All About Materials
In most parts of the country, enough organic materials accumulate
around an average home and yard to make all the compost a backyard
garden needs. You probably have weeds, leaves, perhaps your own
human hair (my wife is the family barber), dust from the vacuum
cleaner, kitchen garbage and grass clippings. But, there may not be
enough to simultaneously build the lushest lawn, the healthiest
ornamentals _and _grow the vegetables. If you want to make more
compost than your own land allows, it is not difficult to find very
large quantities of organic materials that are free or cost very
The most obvious material to bring in for composting is animal
manure. Chicken and egg raisers and boarding stables often give
manure away or sell it for a nominal fee. For a few dollars most
small scale animal growers will cheerfully use their scoop loader to
fill your pickup truck till the springs sag.
As useful as animal manure can be in a compost pile, there are other
types of low C/N materials too. Enormous quantities of loose alfalfa
accumulate around hay bale stacks at feed and grain stores. To the
proprietor this dusty chaff is a nuisance gladly given to anyone
that will neatly sweep it up and truck it away. To the home
gardener, alfalfa in any form is rich as gold.
Some years, rainy Oregon weather is still unsettled at haying season
and farmers are stuck with spoiled hay. I'm sure this happens most
places that grass hay is grown on natural rainfall. Though a shrewd
farmer may try to sell moldy hay at a steep discount by representing
it to still have feed value, actually these ruined bales must be
removed from a field before they interfere with working the land. A
hard bargainer can often get spoiled hay in exchange for hauling the
wet bales out of the field
There's one local farmer near me whose entire family tree holds a
well-deserved reputation for hard, self-interested dealing. One
particularly wet, cool unsettled haying season, after starting the
spoiled-hay dicker at 90 cents per bale asked--nothing offered but
hauling the soggy bales out of the field my offer--I finally agreed
to take away about twenty tons at ten cents per bale. This small sum
allowed the greedy b-----to feel he had gotten the better of me. He
needed that feeling far more than I needed to win the argument or to
keep the few dollars Besides, the workings of self-applied justice
that some religious philosophers call karma show that over the long
haul the worst thing one person can do to another is to allow the
other to get away with an evil act.
Any dedicated composter can make contacts yielding cheap or free
organic materials by the ton. Orchards may have badly bruised or
rotting fruit. Small cider mills, wineries, or a local juice bar
restaurant may be glad to get rid of pomace. Carpentry shops have
sawdust. Coffee roasters have dust and chaff. The microbrewery is
becoming very popular these days; mall-scale local brewers and
distillers may have spent hops and mash. Spoiled product or chaff
may be available from cereal mills.
City governments often will deliver autumn leaves by the ton and
will give away or sell the output of their own municipal composting
operations. Supermarkets, produce wholesalers, and restaurants may
be willing to give away boxes of trimmings and spoiled food. Barbers
and poodle groomers throw away hair.
Seafood processors will sell truckloads of fresh crab, fish and
shrimp waste for a small fee. Of course, this material becomes
evil-smelling in very short order but might be relatively
inoffensive if a person had a lot of spoiled hay or sawdust waiting
to mix into it. Market gardeners near the Oregon coast sheet-compost
crab waste, tilling it into the soil before it gets too "high."
Other parts of the country might supply citrus wastes, sugar cane
bagasse, rice hulls, etc.
About Common Materials
_Alfalfa_ is a protein-rich perennial legume mainly grown as animal
feed. On favorable soil it develops a deep root system, sometimes
exceeding ten feet. Alfalfa draws heavily on subsoil minerals so it
will be as rich or poor in nutrients as the subsoil it grew in. Its
average C/N is around 12:1 making alfalfa useful to compensate for
larger quantities of less potent material. Sacked alfalfa meal or
pellets are usually less expensive (and being "stemmy," have a
slightly higher C/N) than leafy, best-quality baled alfalfa hay.
Rain-spoiled bales of alfalfa hay are worthless as animal feed but
far from valueless to the composter.
Pelletized rabbit feed is largely alfalfa fortified with grain.
Naturally, rabbit manure has a C/N very similar to alfalfa and is
nutrient rich, especially if some provision is made to absorb the
_Apple pomace_ is wet and compact. If not well mixed with stiff,
absorbent material, large clumps of this or other fruit wastes can
become airless regions of anaerobic decomposition. Having a high
water content can be looked upon as an advantage. Dry hay and
sawdust can be hard to moisten thoroughly; these hydrate rapidly
when mixed with fruit pulp. Fermenting fruit pulp attracts yellow
jackets so it is sensible to incorporate it quickly into a pile and
cover well with vegetation or soil.
The watery pulp of fruits is not particularly rich in nutrients but
apple, grape, and pear pulps are generously endowed with soft,
decomposable seeds. Most seeds contain large quantities of
phosphorus, nitrogen, and other plant nutrients. It is generally
true that plants locate much of their entire yearly nutrient
assimilation into their seeds to provide the next generation with
the best possible start. Animals fed on seeds (such as chickens)
produce the richest manures.
Older books about composting warn about metallic pesticide residues
adhering to fruit skins. However, it has been nearly half a century
since arsenic and lead arsenate were used as pesticides and mercury
is no longer used in fungicides.
_Bagasse_ is the voluminous waste product from extracting cane
sugar. Its C/N is extremely high, similar to wheat straw or sawdust,
and it contains very little in the way of plant nutrients. However,
its coarse, strong, fibrous structure helps build lightness into a
pile and improve air flow. Most sugar mills burn bagasse as their
heat source to evaporate water out of the sugary juice squeezed from
the canes. At one time there was far more bagasse produced than the
mills needed to burn and bagasse often became an environmental
pollutant. Then, bagasse was available for nothing or next to
nothing. These days, larger, modern mills generate electricity with
bagasse and sell their surplus to the local power grid. Bagasse is
also used to make construction fiberboard for subwall and
_Banana skins _and stalks are soft and lack strong fiber. They are
moderately rich in phosphorus, potassium, and nitrogen. Consequently
they rot quickly. Like other kitchen garbage, banana waste should be
put into the core of a compost pile to avoid attracting and breeding
flies. See also: _Garbage._
_Basic slag_ is an industrial waste from smelting iron. Ore is
refined by heating it with limestone and dolomite. The impurities
combine with calcium and magnesium, rise to the surface of the
molten metal, and are skimmed off. Basic slag contains quite a bit
of calcium plus a variety of useful plant nutrients not usually
found in limestone. Its exact composition varies greatly depending
on the type of ore used.
Slag is pulverized and sold in sacks as a substitute for
agricultural lime. The intense biological activity of a compost pile
releases more of slag's other mineral content and converts its
nutrients to organic substances that become rapidly available once
the compost is incorporated into soil. Other forms of powdered
mineralized rock can be similarly added to a compost pile to
accelerate nutrient release.
Rodale Press, publisher of _Organic Gardening_ magazine is located
in Pennsylvania where steel mills abound. Having more experience
with slag, Rodale advises the user to be alert to the fact that some
contain little in the way of useful nutrients and/or may contain
excessive amounts of sulfur. Large quantities of sulfur can acidify
soil. Read the analysis on the label. Agriculturally useful slag has
an average composition of 40 percent calcium and 5 percent
magnesium. It must also be very finely ground to be effective. See
also: _Lime_ and _Rock dust._
_Beet wastes,_ like bagasse, are a residue of extracting sugar. They
have commercial value as livestock feed and are sold as dry pulp in
feed stores located near regions where sugar beets are grown. Their
C/N is in the vicinity of 20:1 and they may contain high levels of
potassium, reaching as much as 4 percent.
_Brewery wastes._ Both spent hops (dried flowers and leaves) and
malt (sprouted barley and often other grains) are potent nutrient
sources with low C/N ratios. Spent malt is especially potent because
brewers extract all the starches and convert them to sugar, but
consider the proteins as waste because proteins in the brew make it
cloudy and opaque. Hops may be easier to get. Malt has uses as
animal feed and may be contracted for by some local feedlot or
farmer. These materials will be wet, heavy and frutily odoriferous
(though not unpleasantly so) and you will want to incorporate them
into your compost pile immediately.
_Buckwheat hulls._ Buckwheat is a grain grown in the northeastern
United States and Canada. Adapted to poor, droughty soils, the crop
is often grown as a green manure. The seeds are enclosed in a
thin-walled, brown to black fibrous hulls that are removed at a
groat mill. Buckwheat hulls are light, springy, and airy. They'll
help fluff up a compost heap. Buckwheat hulls are popular as a mulch
because they adsorb moisture easily, look attractive, and stay in
place. Their C/N is high. Oat and rice hulls are similar products.
_Canola meal._ See: _Cottonseed meal._
_Castor pomace_ is pulp left after castor oil has been squeezed from
castor bean seeds. Like other oil seed residues it is very high in
nitrogen, rich in other plant nutrients, particularly phosphorus,
Castor pomace may be available in the deep South; it makes a fine
substitute for animal manure.
_Citrus wastes_ may be available to gardeners living near industrial
processors of orange, lemon, and grapefruit. In those regions, dried
citrus pulp may also be available in feed stores. Dried orange skins
contain about 3 percent phosphorus and 27 percent potassium. Lemons
are a little higher in phosphorus but lower in potassium. Fruit
culls would have a similar nutrient ratio on a dry weight basis, but
they are largely water. Large quantities of culls could be useful to
hydrate stubbornly dry materials like straw or sawdust.
Like other byproducts of industrial farming, citrus wastes may
contain significant amounts of pesticide residues. The composting
process will break down and eliminate most toxic organic residues,
especially if the pile gets really hot through and through. (See
also: _Leaves) _The effect of such high levels of potassium on the
nutritional qualities of my food would also concern me if the
compost I was making from these wastes were used for vegetable
_Coffee grounds_ are nutrient-rich like other seed meals. Even after
brewing they can contain up to 2 percent nitrogen, about 1/2 percent
phosphorus and varying amounts of potassium usually well below 1
percent. Its C/N runs around 12:1. Coffee roasters and packers need
to dispose of coffee chaff, similar in nutrient value to used
grounds and may occasionally have a load of overly roasted beans.
Coffee grounds seem the earthworm's food of choice. In worm bins,
used grounds are more vigorously devoured than any other substance.
If slight odor is a consideration, especially if doing in-the-home
vermicomposting, coffee grounds should be incorporated promptly into
a pile to avoid the souring that results from vinegar-producing
bacteria. Fermenting grounds may also attract harmless fruit flies.
Paper filters used to make drip coffee may be put into the heap or
worm box where they contribute to the bedding. See also: _Paper._
_Corncobs_ are no longer available as an agricultural waste product
because modern harvesting equipment shreds them and spits the
residue right back into the field. However, home gardeners who fancy
sweet corn may produce large quantities of cobs. Whole cobs will
aerate compost heaps but are slow to decompose. If you want your
pile ready within one year, it is better to dry and then grind the
cobs before composting them.
_Cottonseed meal_ is one of this country's major oil seed residues.
The seed is ginned out of the cotton fiber, ground, and then its oil
content is chemically extracted. The residue, sometimes called oil
cake or seed cake, is very high in protein and rich in NPK. Its C/N
runs around 5:1, making it an excellent way to balance a compost
pile containing a lot of carboniferous materials.
Most cottonseed meal is used as animal feed, especially for beef and
dairy cattle. Purchased in garden stores in small containers it is
very expensive; bought by the 50-to 80-pound sack from feed stores
or farm coops, cottonseed meal and other oil seed meals are quite
inexpensive. Though prices of these types of commodities vary from
year to year, oil cakes of all kinds usually cost between $200 to
$400 per ton and only slightly higher purchased sacked in
The price of any seed meal is strongly influenced by freight costs.
Cottonseed meal is cheapest in the south and the southwest where
cotton is widely grown. Soybean meal may be more available and
priced better in the midwest. Canadian gardeners are discovering
canola meal, a byproduct from producing canola (or rapeseed) oil.
When I took a sabbatical in Fiji, I advised local gardeners to use
coconut meal, an inexpensive "waste" from extracting coconut oil.
And I would not be at all surprised to discover gardeners in South
Dakota using sunflower meal. Sesame seed, safflower seed, peanut and
oil-seed corn meals may also be available in certain localities.
Seed meals make an ideal starting point for compounding complete
organic fertilizer mixes. The average NPK analysis of most seed
meals is around 6-4-2. Considered as a fertilizer, oil cakes are
somewhat lacking in phosphorus and sometimes in trace minerals. By
supplementing them with materials like bone meal, phosphate rock,
kelp meal, sometimes potassium-rich rock dusts and lime or gypsum, a
single, wide-spectrum slow-release trace-mineral-rich organic
fertilizer source can be blended at home having an analysis of about
5-5-5. Cottonseed meal is particularly excellent for this purpose
because it is a dry, flowing, odorless material that stores well. I
suspect that cottonseed meal from the southwest may be better
endowed with trace minerals than that from leached-out southeastern
soils or soy meal from depleted midwestern farms. See the last
section of Chapter Eight.
Some organic certification bureaucracies foolishly prohibit or
discourage the use of cottonseed meal as a fertilizer. The rationale
behind this rigid self-righteousness is that cotton, being a nonfood
crop, is sprayed with heavy applications of pesticides and/or
herbicides that are so hazardous that they not permitted on food
crops. These chemicals are usually dissolved in an emulsified
oil-based carrier and the cotton plant naturally concentrates
pesticide residues and breakdown products into the oily seed.
I believe that this concern is accurate as far as pesticide residues
being translocated into the seed. However, the chemical process used
to extract cottonseed oil is very efficient The ground seeds are
mixed with a volatile solvent similar to ether and heated under
pressure in giant retorts. I reason that when the solvent is
squeezed from the seed, it takes with it all not only the oil, but,
I believe, virtually all of the pesticide residues. Besides, any
remaining organic toxins will be further destroyed by the biological
activity of the soil and especially by the intense heat of a compost
What I _personally_ worry about is cottonseed oil. I avoid prepared
salad dressings that may contain cottonseed oil, as well as many
types of corn and potato chips, tinned oysters, and other prepared
food products. I also suggest that you peek into the back of your
favorite Oriental and fast food restaurants and see if there aren't
stacks of ten gallon cottonseed oil cans waiting to fill the
deep-fat fryer. I fear this sort of meal as dangerous to my health.
If you still fear that cottonseed meal is also a dangerous product
then you certainly won't want to be eating feedlot beef or drinking
milk or using other dairy products from cattle fed on cottonseed
_Blood meal_ runs 10-12 percent nitrogen and contains significant
amounts of phosphorus. It is the only organic fertilizer that is
naturally water soluble. Blood meal, like other slaughterhouse
wastes, may be too expensive for use as a compost activator.
Sprinkled atop soil as a side-dressing, dried blood usually provokes
a powerful and immediate growth response. Blood meal is so potent
that it is capable of burning plants; when applied you must avoid
getting it on leaves or stems. Although principally a source of
nitrogen, I reason that there are other nutritional substances like
growth hormones or complex organic "phytamins" in blood meal.
British glasshouse lettuce growers widely agree that lettuce
sidedressed with blood meal about three weeks before harvest has a
better "finish," a much longer shelf-life, and a reduced tendency to
"brown butt" compared to lettuce similarly fertilized with urea or
chemical nitrate sources.
_Feathers_ are the birds' equivalent of hair on animals and have
similar properties. See _Hair_
_Fish and shellfish waste._ These proteinaceous, high-nitrogen and
trace-mineral-rich materials are readily available at little or no
cost in pickup load lots from canneries and sea food processors.
However, in compost piles, large quantities of these materials
readily putrefy, make the pile go anaerobic, emit horrid odors, and
worse, attract vermin and flies. To avoid these problems, fresh
seafood wastes must be immediately mixed with large quantities of
dry, high C/N material. There probably are only a few homestead
composters able to utilize a ton or two of wet fish waste at one
Oregonians pride themselves for being tolerant, slow-to-take-offense
neighbors. Along the Oregon coast, small-scale market gardeners will
thinly spread shrimp or crab waste atop a field and promptly till it
in. Once incorporated in the soil, the odor rapidly dissipates. In
less than one week.
_Fish meal_ is a much better alternative for use around the home. Of
course, you have to have no concern for cost and have your mind
fixed only on using the finest possible materials to produce the
nutritionally finest food when electing to substitute fish meal for
animal manures or oil cakes. Fish meal is much more potent than
cottonseed meal. Its typical nutrient analysis runs 9-6-4. However,
figured per pound of nutrients they contain, seed meals are a much
less expensive way to buy NPK. Fish meal is also mildly odoriferous.
The smell is nothing like wet seafood waste, but it can attract
cats, dogs, and vermin.
What may make fish meal worth the trouble and expense is that sea
water is the ultimate depository of all water-soluble nutrients that
were once in the soil. Animals and plants living in the sea enjoy
complete, balanced nutrition. Weston Price's classic book,
_Nutrition and Physical Degeneration,_ attributes nearly perfect
health to humans who made seafoods a significant portion of their
diets. Back in the 1930s--before processed foods were universally
available in the most remote locations-people living on isolated sea
coasts tended to live long, have magnificent health, and perfect
teeth. See also: _Kelp meal._
_Garbage. _Most forms of kitchen waste make excellent compost. But
Americans foolishly send megatons of kitchen garbage to landfills or
overburden sewage treatment plants by grinding garbage in a
disposal. The average C/N of garbage is rather low so its presence
in a compost heap facilitates the decomposition of less potent
materials. Kitchen garbage can also be recycled in other ways such
as vermicomposting (worm boxes) and burying it in the garden in
trenches or post holes. These alternative composting methods will be
discussed in some detail later.
Putting food scraps and wastes down a disposal is obviously the
least troublesome and apparently the most "sanitary" method, passing
the problem on to others. Handled with a little forethought,
composting home food waste will not breed flies or make the kitchen
untidy or ill smelling. The most important single step in keeping
the kitchen clean and free of odor is to put wastes in a small
plastic bucket or other container of one to two gallons in size, and
empty it every few days. Periodically adding a thin layer of sawdust
or peat moss supposedly helps to prevent smells. In our kitchen,
we've found that covering the compost bucket is no alternative to
emptying it. When incorporating kitchen wastes into a compost pile,
spread them thinly and cover with an inch or two of leaves, dry
grass, or hay to adsorb wetness and prevent access by flies. It may
be advisable to use a vermin-tight composting bin.
_Granite dust._ See _Rock dust._
_Grape wastes._ See _Apple pomace._
_Grass clippings._ Along with kitchen garbage, grass clippings are
the compostable material most available to the average homeowner.
Even if you (wisely) don't compost all of your clippings (see
sidebar), your foolish neighbors may bag theirs up for you to take
away. If you mulch with grass clippings, make sure the neighbors
aren't using "weed and feed" type fertilizers, or the clippings may
cause the plants that are mulched to die. Traces of the those types
of broadleaf herbicides allowed in "weed and feed" fertilizers, are
thoroughly decomposed in the composting process.
It is not necessary to return every bit of organic matter to
maintain a healthy lawn. Perhaps one-third to one-half the annual
biomass production may be taken away and used for composting without
seriously depleting the lawn's vigor--especially if one application
of a quality fertilizer is given to the lawn each year. Probably the
best time of year to remove clippings is during the spring while the
grass is growing most rapidly. Once a clover/grass mix is
established it is less necessary to use nitrogen fertilizers. In
fact, high levels of soil nitrates reduces the clover's ability to
fix atmospheric nitrogen. However, additions of other mineral
nutrients like phosphorus, potassium, and especially calcium may
still be necessary.
Lawn health is similar to garden health. Both depend on the presence
of large enough quantities of organic material in the soil. This
organic matter holds a massive reserve of nutrition built up over
the years by the growing plants themselves. When, for reasons of
momentary aesthetics, we bag up and remove clippings from our lawn,
we prevent the grass from recycling its own fertility.
It was once mistakenly believed that unraked lawn clippings built up
on the ground as unrotted thatch, promoting harmful insects and
diseases. This is a half-truth. Lawns repeatedly fertilized with
sulfur-based chemical fertilizers, especially ammonium sulfate and
superphosphate, become so acid and thus so hostile to bacterial
decomposition and soil animals that a thatch of unrotted clippings
and dead sod can build up and thus promote disease and insect
However, lawns given lime or gypsum to supply calcium that is so
vital to the healthy growth of clover, and seed meals and/or
dressings of finely decomposed compost or manure become naturally
healthy. Clippings falling on such a lawn rot rapidly because of the
high level of microorganisms in the soil, and disappear in days.
Dwarf white clover can produce all the nitrate nitrogen that grasses
need to stay green and grow lustily. Once this state of health is
developed, broadleaf weeds have a hard time competing with the lusty
grass/clover sod and gradually disappear. Fertilizing will rarely be
necessary again if little biomass is removed.
Homeowners who demand the spiffy appearance of a raked lawn but
still want a healthy lawn have several options. They may compost
their grass clippings and then return the compost to the lawn. They
may use a side-discharge mower and cut two days in succession. The
first cut will leave rows of clippings to dry on the lawn; the
second cut will disintegrate those clippings and pretty much make
them disappear. Finally, there are "mulching" mowers with blades
that chop green grass clippings into tiny pieces and drops them
below the mower where they are unnoticeable.
Grass clippings, especially spring grass, are very high in nitrogen,
similar to the best horse or cow manure. Anyone who has piled up
fresh grass clippings has noticed how rapidly they heat up, how
quickly the pile turns into a slimy, airless, foul-smelling
anaerobic mess, and how much ammonia may be given off. Green grass
should be thoroughly dispersed into a pile, with plenty of dry
material. Reserve bags of leaves from the fall or have a bale of
straw handy to mix in if needed. Clippings allowed to sun dry for a
few days before raking or bagging behave much better in the compost
_Greensand._ See _Rock dust._
_Hair _contains ten times the nitrogen of most manures. It resists
absorbing moisture and readily compresses, mats, and sheds water, so
hair needs to be mixed with other wetter materials. If I had easy
access to a barber shop, beauty salon, or poodle grooming business,
I'd definitely use hair in my compost. Feathers, feather meal and
feather dust (a bird's equivalent to hair) have similar qualities.
_Hay._ In temperate climates, pasture grasses go through an annual
cycle that greatly changes their nutrient content. Lawn grasses are
not very different. The first cuttings of spring grass are potent
sources of nitrogen, high in protein and other vital mineral
nutrients. In fact, spring grass may be as good an animal feed as
alfalfa or other legume hay. Young ryegrass, for example, may exceed
two percent nitrogen-equaling about 13 percent protein. That's why
cattle and horses on fresh spring grass frisk around and why June
butter is so dark yellow, vitamin-rich and good-flavored.
In late spring, grasses begin to form seed and their chemical
composition changes. With the emergence of the seed stalk, nitrogen
content drops markedly and the leaves become more fibrous,
ligninous, and consequently, more reluctant to decompose. At
pollination ryegrass has dropped to about l percent nitrogen and by
the time mature seed has developed, to about 0.75 percent.
These realities have profound implications for hay-making, for using
grasses as green manures, and for evaluating the C/N of hay you may
be planning to use in a compost heap. In earlier times, making grass
hay that would be nutritious enough to maintain the health of cattle
required cutting the grass before, or just at, the first appearance
of seed stalks. Not only did early harvesting greatly reduce the
bulk yield, it usually meant that without concern for cost or hours
of labor the grass had to be painstakingly dried at a time of year
when there were more frequent rains and lower temperatures. In
nineteenth-century England, drying grass was draped by hand over low
hurdles, dotting each pasture with hundreds of small racks that shed
water like thatched roofs and allowed air flow from below. It is
obvious to me where the sport of running hurdles came from; I
envision energetic young countryfolk, pepped up on that rich spring
milk and the first garden greens of the year, exuberantly racing
each other across the just-mowed fields during haying season.
In more recent years, fresh wet spring grass was packed green into
pits and made into silage where a controlled anaerobic fermentation
retained its nutritional content much like sauerkraut keeps cabbage.
Silage makes drying unnecessary. These days, farm labor is expensive
and tractors are relatively inexpensive. It seems that grass hay
must be cut later when the weather is more stable, economically
dried on the ground, prevented from molding by frequent raking, and
then baled mechanically.
In regions enjoying relatively rainless springs or where agriculture
depends on irrigation, this system may result in quality hay. But
most modern farmers must supplement the low-quality hay with oil
cakes or other concentrates. Where I live, springs are cool and damp
and the weather may not stabilize until mid-June. By this date grass
seed is already formed and beginning to dry down. This means our
local grass hay is very low in protein, has a high C/N, and is very
woody--little better than wheat straw. Pity the poor horses and
cattle that must try to extract enough nutrition from this stuff.
Western Oregon weather conditions also mean that farmers often end
up with rain-spoiled hay they are happy to sell cheaply. Many years
I've made huge compost piles largely from this kind of hay. One
serious liability from cutting grass hay late is that it will
contain viable seeds. If the composting process does not thoroughly
heat all of these seeds, the compost will sprout grass all over the
garden. One last difficulty with poor quality grass hay: the tough,
woody stems are reluctant to absorb moisture.
The best way to simultaneously overcome all of these liabilities is
first to permit the bales to thoroughly spoil and become moldy
through and through before composting them. When I have a ton or two
of spoiled hay bales around, I spread them out on the ground in a
single layer and leave them in the rain for an entire winter. Doing
this sprouts most of the grass seed within the bales, thoroughly
moistens the hay, and initiates decomposition. Next summer I pick up
this material, remove the baling twine, and mix it into compost
piles with plenty of more nitrogenous stuff.
One last word about grass and how it works when green manuring. If a
thick stand of grasses is tilled in during spring before seed
formation begins, its high nitrogen content encourages rapid
decomposition. Material containing 2 percent nitrogen and lacking a
lot of tough fiber can be totally rotted and out of the way in two
weeks, leaving the soil ready to plant. This variation on green
manuring works like a charm.
However, if unsettled weather conditions prevent tillage until seed
formation has begun, the grasses will contain much less nitrogen and
will have developed a higher content of resistant lignins. If the
soil does not become dry and large reserves of nitrogen are already
waiting in the soil to balance the high C/N of mature grass, it may
take only a month to decompose But there will be so much
decomposition going on for the first few weeks that even seed
germination is inhibited. Having to wait an unexpected month or six
weeks after wet weather prevented forming an early seed bed may
delay sowing for so long that the season is missed for the entire
year. Obstacles like this must be kept in mind when considering
using green manuring as a soil-building technique. Cutting the grass
close to the soil line and composting the vegetation off the field
eliminates this problem.
_Hoof and horn meal._ Did you know that animals construct their
hooves and horns from compressed hair? The meal is similar in
nutrient composition to blood meal, leather dust, feather meal, or
meat meal (tankage). It is a powerful source of nitrogen with
significant amounts of phosphorus. Like other slaughterhouse
byproducts its high cost may make it impractical to use to adjust
the C/N of compost piles. Seed meals or chicken manure (chickens are
mainly fed seeds) have somewhat lower nitrogen contents than animal
byproducts but their price per pound of actual nutrition is more
reasonable. If hoof and horn meal is not dispersed through a pile it
may draw flies and putrefy. I would prefer to use expensive
slaughterhouse concentrates to blend into organic fertilizer mixes.
_Juicer pulp:_ See _Apple pomace._
_Kelp meals_ from several countries are available in feed and grain
stores and better garden centers, usually in 25 kg (55-pound) sacks
ranging in cost from $20 to $50. Considering this spendy price, I
consider using kelp meal more justifiable in complete organic
fertilizer mixes as a source of trace minerals than as a composting
There is a great deal of garden lore about kelp meal's
growth-stimulating and stress-fortifying properties. Some
garden-store brands tout these qualities and charge a very high
price. The best prices are found at feed dealers where kelp meal is
considered a bulk commodity useful as an animal food supplement.
I've purchased kelp meal from Norway, Korea, and Canada. There are
probably other types from other places. I don't think there is a
significant difference in the mineral content of one source compared
to another. I do not deny that there may be differences in how well
the packers processing method preserved kelp's multitude of
beneficial complex organic chemicals that improve the growth and
overall health of plants by functioning as growth stimulants,
phytamins, and who knows what else.
Still, I prefer to buy by price, not by mystique, because, after
gardening for over twenty years, garden writing for fifteen and
being in the mail order garden seed business for seven I have been
on the receiving end of countless amazing claims by touters of
agricultural snake oils; after testing out dozens of such
concoctions I tend to disbelieve mystic contentions of unique
superiority. See also: _Seaweed_.
_Leather dust_ is a waste product of tanneries, similar to hoof and
horn meal or tankage. It may or may not be contaminated with high
levels of chromium, a substance used to tan suede. If only
vegetable-tanned leather is produced at the tannery in question,
leather dust should be a fine soil amendment. Some organic
certification bureaucrats prohibit its use, perhaps rightly so in
_Leaves._ Soil nutrients are dissolved by rain and leached from
surface layers, transported to the subsoil, thence the ground water,
and ultimately into the salty sea. Trees have deep root systems,
reaching far into the subsoil to bring plant nutrients back up,
making them nature's nutrient recycler. Because they greatly
increase soil fertility, J. Russell Smith called trees "great
engines of production." Anyone who has not read his visionary book,
_Tree Crops, _should. Though written in 1929, this classic book is
currently in print.
Once each year, leaves are available in large quantity, but aren't
the easiest material to compost. Rich in minerals but low in
nitrogen, they are generally slow to decompose and tend to pack into
an airless mass. However, if mixed with manure or other
high-nitrogen amendment and enough firm material to prevent
compaction, leaves rot as well as any other substance. Running dry
leaves through a shredder or grinding them with a lawnmower greatly
accelerates their decomposition. Of all the materials I've ever put
through a garden grinder, dry leaves are the easiest and run the
Once chopped, leaves occupy much less volume. My neighbor, John, a
very serious gardener like me, keeps several large garbage cans
filled with pulverized dry leaves for use as mulch when needed. Were
I a northern gardener I'd store shredded dry leaves in plastic bags
over the winter to mix into compost piles when spring grass
clippings and other more potent materials were available. Some
people fear using urban leaves because they may contain automotive
pollutants such as oil and rubber components. Such worries are
probably groundless. Dave Campbell who ran the City of Portland
(Oregon) Bureau of Maintenance leaf composting program said he has
run tests for heavy metals and pesticide residues on every windrow
of compost he has made.
"Almost all our tests so far have shown less than the background
level for heavy metals, and no traces of pesticides [including]
chlorinated and organophosphated pesticides.... It is very rare for
there to be any problem."
Campbell tells an interesting story that points out how thoroughly
composting eliminates pesticide residues. He said,
"Once I was curious about some leaves we were getting from a city
park where I knew the trees had been sprayed with a pesticide just
about a month before the leaves fell and we collected them. In this
case, I had the uncomposted leaves tested and then the compost
tested. In the fresh leaves a trace of . . . residue was detected,
but by the time the composting process was finished, no detectable
level was found."
_Lime._ There is no disputing that calcium is a vital soil nutrient
as essential to the formation of plant and animal proteins as
nitrogen. Soils deficient in calcium can be inexpensively improved
by adding agricultural lime which is relatively pure calcium
carbonate (CaC03). The use of agricultural lime or dolomitic lime in
compost piles is somewhat controversial. Even the most authoritative
of authorities disagree. There is no disputing that the calcium
content of plant material and animal manure resulting from that
plant material is very dependent on the amount of calcium available
in the soil. Chapter Eight contains quite a thorough discussion of
this very phenomena. If a compost pile is made from a variety of
materials grown on soils that contained adequate calcium, then
adding additional lime should be unnecessary. However, if the
materials being composted are themselves deficient in calcium then
the organisms of decomposition may not develop fully.
While preparing this book, I queried the venerable Dr. Herbert H.
Koepf about lime in the compost heap. Koepf's biodynamic books
served as my own introduction to gardening in the early 1970s. He is
still active though in his late seventies. Koepf believes that lime
is not necessary when composting mixtures that contain significant
amounts of manure because the decomposition of proteinaceous
materials develops a more or less neutral pH. However, when
composting mixtures of vegetation without manure, the conditions
tend to become very acid and bacterial fermentation is inhibited. To
correct low pH, Koepf recommends agricultural lime at 25 pounds per
ton of vegetation, the weight figured on a dry matter basis. To
guestimate dry weight, remember that green vegetation is 70-80
percent water, to prevent organic material like hay from spoiling it
is first dried down to below 15 percent moisture.
There is another reason to make sure that a compost pile contains an
abundance of calcium. Azobacteria, that can fix nitrate nitrogen in
mellowing compost piles, depend for their activity on the
availability of calcium. Adding agricultural lime in such a
situation may be very useful, greatly speed the decomposition
process, and improve the quality of the compost. Albert Howard used
small amounts of lime in his compost piles specifically to aid
nitrogen fixation. He also incorporated significant quantities of
fresh bovine manure at the same time.
However, adding lime to heating manure piles results in the loss of
large quantities of ammonia gas. Perhaps this is the reason some
people are opposed to using lime in any composting process. Keep in
mind that a manure pile is not a compost pile. Although both will
heat up and decay, the starting C/N of a barnyard manure pile runs
around 10:1 while a compost heap of yard waste and kitchen garbage
runs 25:1 to 30:1. Any time highly nitrogenous material, such as
fresh manures or spring grass clippings, are permitted to decompose
without adjustment of the carbon-to-nitrogen ratio with less potent
stuff, ammonia tends to be released, lime or not.
Only agricultural lime or slightly better, dolomitic lime, are
useful in compost piles. Quicklime or slaked lime are made from
heated limestone and undergo a violent chemical reaction when mixed
with water. They may be fine for making cement, but not for most
_Linseed meal._ See _Cottonseed meal_.
_Manure._ Fresh manure can be the single most useful addition to the
compost pile. What makes it special is the presence of large
quantities of active digestive enzymes. These enzymes seem to
contribute to more rapid heating and result in a finer-textured,
more completely decomposed compost that provokes a greater growth
response in plants. Manure from cattle and other multi-stomached
ruminants also contains cellulose-decomposing bacteria. Soil animals
supply similar digestive enzymes as they work over the litter on the
forest floor but before insects and other tiny animals can eat much
of a compost heap, well-made piles will heat up, driving out or
killing everything except microorganisms and fungi.
All of the above might be of interest to the country dweller or
serious backyard food grower but probably sounds highly impractical
to most of this book's readers. Don't despair if fresh manure is not
available or if using it is unappealing. Compost made with fresh,
unheated manure works only a little faster and produces just a
slightly better product than compost activated with seed meals,
slaughterhouse concentrates, ground alfalfa, grass clippings,
kitchen garbage, or even dried, sacked manures. Compost made without
any manure still "makes!"
When evaluating manure keep in mind the many pitfalls. Fresh manure
is very valuable, but if you obtain some that has been has been
heaped up and permitted to heat up, much of its nitrogen may already
have dissipated as ammonia while the valuable digestive enzymes will
have been destroyed by the high temperatures at the heap's core. A
similar degradation happens to digestive enzymes when manure is
dried and sacked. Usually, dried manure comes from feedlots where it
has also first been stacked wet and gone through a violent heating
process. So if I were going to use sacked dried manure to lower the
C/N of a compost pile, I'd evaluate it strictly on its cost per
pound of actual nitrogen. In some cases, seed meals might be cheaper
and better able to drop the heap's carbon-to-nitrogen ratio even
more than manure.
There are many kinds of manure and various samples of the same type
of manure may not be equal. This demonstrates the principle of what
goes in comes out. Plants concentrate proteins and mineral nutrients
in their seed so animals fed on seed (like chickens) excrete manure
nearly as high in minerals and with a C/N like seed meals (around
8:1). Alfalfa hay is a legume with a C/N around 12:1. Rabbits fed
almost exclusively on alfalfa pellets make a rich manure with a
similar C/N. Spring grass and high quality hay and other leafy
greens have a C/N nearly as good as alfalfa. Livestock fed the best
hay supplemented with grain and silage make fairly rich manure. Pity
the unfortunate livestock trying to survive as "strawburners" eating
overly mature grass hay from depleted fields. Their manure will be
as poor as the food and soil they are trying to live on.
When evaluating manure, also consider the nature and quantity of
bedding mixed into it. Our local boarding stables keep their lazy
horses on fir sawdust. The idle "riding" horses are usually fed very
strawy local grass hay with just enough supplemental alfalfa and
grain to maintain a minimal healthy condition. The "horse manure"
I've hauled from these stables seems more sawdust than manure. It
must have a C/N of 50 or 60:1 because by itself it will barely heat
Manure mixed with straw is usually richer stuff. Often this type
comes from dairies. Modern breeds of milk cows must be fed seed
meals and other concentrates to temporarily sustain them against
depletion from unnaturally high milk production.
After rabbit and chicken, horse manure from well-fed animals like
race horses or true, working animals may come next. Certainly it is
right up there with the best cow manure. Before the era of chemical
fertilizer, market gardeners on the outskirts of large cities took
wagon loads of produce to market and returned with an equivalent
weight of "street sweepings." What they most prized was called
"short manure," or horse manure without any bedding. Manure and
bedding mixtures were referred to as "long manure" and weren't
considered nearly as valuable.
Finally, remember that over half the excretion of animals is urine.
And far too little value is placed on urine. As early as 1900 it was
well known that if you fed one ton (dry weight) of hay and measured
the resulting manure after thorough drying, only 800 pounds was
left. What happened to the other 1,200 pounds of dry material? Some,
of course, went to grow the animal. Some was enzymatically "burned"
as energy fuel and its wastes given off as CO2 and H2O. Most of it
was excreted in liquid form. After all, what is digestion but an
enzymatic conversion of dry material into a water solution so it can
be circulated through the bloodstream to be used and discarded as
needed. Urine also contains numerous complex organic substances and
cellular breakdown products that improve the health of the soil
However, urine is not easy to capture. It tends to leach into the
ground or run off when it should be absorbed into bedding. Chicken
manure and the excrements of other fowl are particularly valuable in
this respect because the liquids and solids of their waste are
uniformly mixed so nothing is lost. When Howard worked out his
system of making superior compost at Indore, he took full measure of
the value of urine and paid great care to its capture and use.
_Paper_ is almost pure cellulose and has a very high C/N like straw
or sawdust. It can be considered a valuable source of bulk for
composting if you're using compost as mulch. Looked upon another
way, composting can be a practical way to recycle paper at home.
The key to composting paper is to shred or grind it. Layers of paper
will compress into airless mats. Motor-driven hammermill shredders
will make short work of dry paper. Once torn into tiny pieces and
mixed with other materials, paper is no more subject to compaction
than grass clippings. Even without power shredding equipment,
newsprint can be shredded by hand, easily ripped into narrow strips
by tearing whole sections along the grain of the paper, not fighting
Evaluating Nitrogen Content
A one-cubic foot bag of dried steer manure weighs 25 pounds and is
labeled 1 percent nitrogen. That means four sacks weighs 100 pounds
and contains 1 pound of actual nitrogen.
A fifty pound bag of cottonseed meal contains six percent nitrogen.
Two sacks weighs 100 pounds and contains 6 pounds of actual
Therefore it takes 24 sacks of steer manure to equal the nitrogen
contained in two sacks of cottonseed meal.
If steer manure costs $1.50 per sack, six pound of actual nitrogen
from steer manure costs 24 x $1.50 = $36.00
If fifty pounds of cottonseed meal costs $7.50, then six pounds of
actual nitrogen from cottonseed meal costs 2 x $7.50 = $15.00.
Now, lets take a brief moment to see why industrial farmers thinking
only of immediate financial profit, use chemical fertilizers. Urea,
a synthetic form of urine used as nitrogen fertilizer contains 48
percent nitrogen. So 100 pounds of urea contains 48 pounds of
nitrogen. That quantity of urea also costs about $15.00!
Without taking into account its value in terms of phosphorus,
potassium and other mineral contents, nitrogen from seed meal costs
at least eight times as much per pound as nitrogen from urea.
Newspapers, even with colored inks, can be safely used in compost
piles. Though some colored inks do contain heavy metals, these are
not used on newsprint.
However, before beginning to incorporate newsprint into your
composting, reconsider the analyses of various types of compost
broken out as a table in the previous chapter. The main reason many
municipal composting programs make a low-grade product with such a
high C/N is the large proportion of paper used. If your compost is
intended for use as mulch around perennial beds or to be screened
and broadcast atop lawns, then having a nitrogen-poor product is of
little consequence. But if your compost is headed for the vegetable
garden or will be used to grow the largest possible prized flowers
then perhaps newsprint could be recycled in another way.
Cardboard, especially corrugated material, is superior to newsprint
for compost making because its biodegradable glues contain
significant amounts of nitrogen. Worms love to consume cardboard
mulch. Like other forms of paper, cardboard should be shredded,
ground or chopped as finely as possible, and thoroughly mixed with
other materials when composted._
__Pet wastes_ may contain disease organisms that infect humans.
Though municipal composting systems can safely eliminate such
diseases, home composting of dog and cat manure may be risky if the
compost is intended for food gardening.
_Phosphate rock._ If your garden soil is deficient in phosphorus,
adding rock phosphate to the compost pile may accelerate its
availability in the garden, far more effectively than adding
phosphate to soil. If the vegetation in your vicinity comes from
soils similarly deficient in phosphorus, adding phosphate rock will
support a healthier decomposition ecology and improve the quality of
your compost. Five to ten pounds of rock phosphate added to a cubic
yard of uncomposted organic matter is about the right amount.
_Rice hulls:_ See _Buckwheat hulls._
_Rock dust._ All plant nutrients except nitrogen originally come
from decomposing rock. Not all rocks contain equal concentrations
and assortments of the elements plants use for nutrients.
Consequently, not all soils lustily grow healthy plants. One very
natural way to improve the over all fertility of soil is to spread
and till in finely ground rock flour make from highly mineralized
This method is not a new idea. Limestone and dolomite--soft, easily
powdered rocks--have been used for centuries to add calcium and
magnesium. For over a century, rock phosphate and kainite--a soft,
readily soluble naturally occurring rock rich in potassium,
magnesium and sulfur--have been ground and used as fertilizer. Other
natural rock sources like Jersey greensand have long been used in
the eastern United States on some unusual potassium-deficient soils.
Lately it has become fashionable to remineralize the earth with
heavy applications of rock flours. Unlike most fads and trends, this
one is wise and should endure. The best rocks to use are finely
ground "basic" igneous rocks like basalts. They are called basic as
opposed to "acid" rocks because they are richer in calcium and
magnesium with lesser quantities of potassium. When soil forms from
these materials it tends to not be acid. Most basic igneous rocks
also contain a wide range of trace mineral nutrients. I have
observed marked improvements in plant growth by incorporating
ordinary basalt dust that I personally shoveled from below a
conveyor belt roller at a local quarry where crushed rock was being
prepared for road building. Basalt dust was an unintentional
Though highly mineralized rock dust may be a valuable soil
amendment, its value must equal its cost. Application rates of one
or two tons per acre are minimal. John Hamaker's _The Survival of
Civilization _suggests eight to ten tons per acre the first
application and then one or two tons every few years thereafter.
This means the correct price for rock dust is similar to the price
for agricultural lime; in my region that's about $60 to $80 a ton in
sacks. Local farmers pay about $40 a ton in bulk, including
spreading on your field by the seller. A fifty-pound sack of rock
dust should retail for about $2. These days it probably costs
several times that price, tending to keep rock dust a novelty item.
The activities of fungi and bacteria are the most potent forces
making nutrients available to plants. As useful as tilling rock
powders into soil may be, the intense biological activity of the
compost pile accelerates their availability. And the presence of
these minerals might well make a compost pile containing
nutrient-deficient vegetation work faster and become better
fertilizer. Were the right types of rock dust available and cheap,
I'd make it about 5 percent by volume of my heap, and equal that
with rich soil.
_Safflowerseed meal._ See _Cottonseed meal._
_Sawdust_ contains virtually nothing but carbon. In small quantities
it is useful to fluff up compost piles and prevent compaction.
However this is only true of coarse material like that from sawmills
or chain saws. The fine saw dust from carpentry and cabinet work may
compact and become airless. See _Paper _for a discussion of lowering
the fertilizing value of compost with high C/N materials.
_Seaweed_ when freshly gathered is an extraordinary material for the
compost pile. Like most living things from the ocean seaweeds are
rich in all of the trace minerals and contain significant amounts of
the major nutrients, especially potassium, with lesser amounts of
phosphorus and nitrogen. Seaweeds enrich the heap, decompose very
rapidly, and assist other materials to break down. Though heavy and
often awkward to gather and haul, if they are available, seaweeds
should not be permitted to go to waste.
Those with unlimited money may use sprinklings of kelp meal in the
compost pile to get a similar effect. However, kelp meal may be more
economically used as part of a complete organic fertilizer mixture
that is worked into soil.
_Shrub and tree_ prunings are difficult materials to compost unless
you have a shredder/chipper. Even after being incorporated into one
hot compost heap after another, half-inch diameter twigs may take
several years to fully decompose. And turning a heap containing long
branches can be very difficult. But buying power equipment just to
grind a few cart loads of hedge and tree prunings each year may not
be economical. My suggestion is to neatly tie any stick larger than
your little finger into tight bundles about one foot in diameter and
about 16 inches long and then burn these "faggots" in the fireplace
or wood stove. This will be less work in the long run.
Soil is an often overlooked but critically important part of the
compost pile. Least of its numerous benefits, soil contains
infinitudes of microorganisms that help start out decomposition.
Many compostable materials come with bits of soil already attached
and few are sterile in themselves. But extra soil ensures that there
will initially be a sufficient number and variety of these valuable
organisms. Soil also contains insoluble minerals that are made
soluble by biological activity. Some of these minerals may be in
short supply in the organic matter itself and their addition may
improve the health and vigor of the whole decomposition ecology. A
generous addition of rock dust may do this even better.
Most important, soil contains nitrification microorganisms that
readily convert ammonia gas to nitrates, and clay that will catch
and temporarily hold ammonia. Nitrifying bacteria do not live
outside of soil. Finally, a several inch thick layer of soil capping
the heap serves as an extra insulator, holding in heat, raising the
core temperature and helping seal in moisture. Making a compost heap
as much as 10 percent soil by dry weight is the right target
Try thinking of soil somewhat like the moderators in an atomic
reactor, controlling the reaction by trapping neutrons. Soil won't
change the C/N of a heap but not being subject to significant
breakdown it will slightly lower the maximum temperature of
decomposition; while trapping ammonia emissions; and creating better
conditions for nitrogen fixing bacteria to improve the C/N as the
heap cools and ripens.
_Soybean meal._ See _Cottonseed meal._
_Straw_ is a carboniferous material similar to sawdust but usually
contains more nutrients. It is a valuable aerator, each stalk acting
as a tube for air to enter and move through the pile. Large
quantities of long straw can make it very difficult to turn a heap
the first time. I'd much prefer to have manure mixed with straw than
_Sunflowerseed meal._ See _Cottonseed meal._
_Tankage_ is another slaughterhouse or rendering plant waste
consisting of all animal refuse except blood and fat. Locally it is
called meat meal. See _Hoof and horn meal._
_Tofu factory waste._ Okara is the pulp left after soy milk has been
squeezed from cooked, ground soybeans. Small-scale tofu makers will
have many gallons of okara to dispose of each day. It makes good pig
food so there may be competition to obtain it. Like any other seed
waste, okara is high in nitrogen and will be wet and readily
putrefiable like brewery waste. Mix into compost piles immediately.
_Urine._ See _Manure._
_Weeds. _Their nutrient content is highly variable depending on the
species and age of the plant. Weeds gone to seed are both low in
nitrogen and require locating in the center of a hot heap to kill
off the seeds. Tender young weeds are as rich in nitrogen as spring
Weeds that propagate through underground stems or rhizomes like
quack-grass, Johnsongrass, bittersweet, and the like are better
_Wood ash_ from hardwoods is rich in potassium and contains
significant amounts of calcium and other minerals. Ash from conifers
may be similarly rich in potassium but contains little else. Wood
ashes spread on the ground tend to lose their nutrients rapidly
through leaching. If these nutrients are needed in your soil, then
add the ash to your compost piles where it will become an
unreachable part of the biomass that will be gradually released in
the garden when the compost is used.
_Wood chips _are slow to decompose although they may be added to the
compost pile if one is not in a hurry. Their chunkiness and stiff
mechanical properties help aerate a heap. They are somewhat more
nutrient rich than sawdust.
_Wool wastes_ are also called shoddy. _See Hair._
Methods and Variations
_A note to the internet reader: In the the print-on-paper edition,
this chapter and the next one on vermicomposting are full of
illustrations showing composting structures and accessories. These
do not reproduce well on-line and are not included._
Growing the majority of my family's food absorbs all of the energy I
care to put into gardening. So my yard is neat but shaggy. Motivated
by what I consider total rationality, my lawn is cut only when it
threatens to overwhelm the lawnmower, and the lawn is not irrigated,
so it browns off and stops growing in summer.
I don't grow flowers because I live on a river in a beautiful
countryside setting surrounded by low mountains. Nothing I created
could begin to compete with what nature freely offers my eye. One
untidy bed of ornamentals by the front door are my bow to
conventionality, but these fit the entrances northeast aspect by
being Oregon woods natives like ferns, salal, Oregon grape and an
almost wild rhododendron--all these species thrive without
When I give lectures, I am confronted by the amazing gardening
variations that humans are capable of. Some folks' raised vegetable
beds are crude low mounds. Then, I am shown photographs of squared,
paralleled vertical-walled raised beds, uniformly wrapped in cedar
planks. Some gardens are planted in fairly straight rows, some are
laid-out in carefully calculated interplanted hexagonal successions
and some are a wild scattering of catch-as-catch-can. Some people
don't eat many kinds of vegetables yet grow large stands of corn and
beans for canning or freezing.
Others grow small patches of a great many species, creating a
year-round gourmet produce stand for their personal enjoyment. Some
gardeners grow English-style floral displays occupying every square
inch of their yards and offering a constant succession of color and
This chapter presents some of the many different ways people handle
the disposal of yard and kitchen wastes. Compost making, like
gardening, reflects variations in temperament. You probably weren't
surprised at my casual landscaping because you already read about my
unkempt compost heap. So I am similarly not surprised to discover
backyard composting methods as neat as a German village, as
aesthetic as a Japanese garden, as scientific as an engineer would
design and as ugly as . . .
Containers and Other Similar Methods
In my days of youthful indiscretions I thought I could improve life
on Earth by civilizing high school youth through engendering in them
an understanding of history. I confess I almost completely failed
and gave up teaching after a few years. However, I personally
learned a great deal about history and the telling of history. I
read many old journals, diaries, and travel accounts. From some of
these documents I gained little while other accounts introduced me
to unique individuals who assisted me in understanding their era.
It seems that what differentiates good from bad reporting is how
frank and honest the reporter is about their own personal opinions,
prejudices, and outlooks. The more open and direct the reporter, the
better the reader can discount inevitable distortions and get a
picture of what might really have been there. The more the reporter
attempts to be "objective" by hiding their viewpoints, the less
valuable their information.
That is why before discussing those manufactured aids to composting
that can make a consumer of you, I want to inform you that I am a
frugal person who shuns unnecessary expenditure. I maintain what
seems to me to be a perfect justification for my stinginess: I
prefer relative unemployment. Whenever I want to buy something it
has become my habit first to ask myself if the desired object could
possibly bring me as much pleasure as knowing that I don't have to
get up and go to work the next morning. Usually I decide to save the
money so I do not have to earn more. _En extremis,_ I repeat the old
Yankee marching chant like a mantra: Make do! Wear it out! When it
is gone, do without! Bum, Bum! Bum bi Dum! Bum bi di Dum, Bum bi
So I do not own a shredder/grinder when patience will take its
place. I do not buy or make composting containers when a country
life style and not conforming to the neatness standards of others
makes bins or tumblers unnecessary. However, I do grudgingly accept
that others live differently. Let me warn you that my descriptions
of composting aids and accessories are probably a little jaundiced.
I am doing my best to be fair.
Visual appeal is the primary benefit of making compost in a
container. To a tidy, northern European sense of order, any
composting structure will be far neater than the raw beauty of a
naked heap. Composting container designs may offer additional
advantages but no single structure will do everything possible. With
an enclosure, it may be possible to heat up a pile smaller than 1' x
4' x 4' because the walls and sometimes the top of the container may
be insulating. This is a great advantage to someone with a postage
stamp backyard that treasures every square foot. Similarly, wrapping
the heap retards moisture loss. Some structures shut out vermin.
On the other hand, structures can make it more difficult to make
compost. Using a prefabricated bin can prevent a person from readily
turning the heap and can almost force a person to also buy some sort
of shredder/chipper to first reduce the size of the material. Also,
viewed as a depreciating economic asset with a limited life span,
many composting aids cost as much or more money as the value of all
the material they can ever turn out. Financial cost relates to
ecological cost, so spending money on short-lived plastic or easily
rusted metal may negate any environmental benefit gained from
recycling yard wastes.
Building Your Own Bin
Probably the best homemade composting design is the multiple bin
system where separate compartments facilitate continuous
decomposition. Each bin is about four feet on a side and three to
four feet tall. Usually, the dividing walls between bins are shared.
Always, each bin opens completely at the front. I think the best
design has removable slatted separators between a series of four
(not three) wooden bins in three declining sizes: two large, one
medium-large and one smaller. Alternatively, bins may be constructed
of unmortared concrete blocks with removable wooden fronts.
Permanently constructed bins of mortared concrete block or wood may
have moisture-retentive, rain-protective hinged lids.
There are two workable composting systems that fit these structures.
Most composters obtain materials too gradually to make a large heap
all at once. In this case my suggestion is the four-bin system,
using one large bin as a storage area for dry vegetation. Begin
composting in bin two by mixing the dry contents temporarily stored
in bin one with kitchen garbage, grass clippings and etc. Once bin
two is filled and heating, remove its front slats and the side slats
separating it from bin three and turn the pile into bin three,
gradually reinserting side slats as bin three is filled. Bin three,
being about two-thirds the size of bin two, will be filled to the
brim. A new pile can be forming in bin two while bin three is
When bin three has settled significantly, repeat the process,
turning bin three into bin four, etc. By the time the material has
reheated in bin four and cooled you will have finished or
close-to-finished compost At any point during this turning that
resistant, unrotted material is discovered, instead of passing it
on, it may be thrown back to an earlier bin to go through yet
another decomposition stage. Perhaps the cleverest design of this
type takes advantage of any significant slope or hill available to a
lazy gardener and places a series of separate bins one above the
next, eliminating any need for removable side-slats while making
tossing compost down to the next container relatively easy.
A simply constructed alternative avoids making removable slats
between bins or of lifting the material over the walls to toss it
from bin to bin. Here, each bin is treated as a separate and
discrete compost process. When it is time to turn the heap, the
front is removed and the heap is turned right back into its original
container. To accomplish this it may be necessary to first shovel
about half of the material out of the bin onto a work area, then
turn what is remaining in the bin and then cover it with what was
shoveled out. Gradually the material in the bin shrinks and
decomposes. When finished, the compost will fill only a small
fraction of the bin's volume.
My clever students at the Urban Farm Class, University of Oregon
have made a very inexpensive compost bin structure of this type
using recycled industrial wood pallets. They are held erect by
nailing them to pressure-treated fence posts sunk into the earth.
The removable doors are also pallets, hooked on with bailing wire.
The flimsy pallets rot in a couple of years but obtaining more free
pallets is easy. If I were building a more finished three or four
bin series, I would use rot-resistant wood like cedar and/or
thoroughly paint the wood with a non-phytotoxic wood preservative
like Cuprinol (copper napthanate). Cuprinol is not as permanent as
other types of wood preservatives and may have to be reapplied every
two or three years.
Bins reduce moisture loss and wood bins have the additional
advantage of being fairly good thermal insulators: one inch of wood
is as much insulation as one foot of solid concrete. Composting
containers also have a potential disadvantage-reducing air flow,
slowing decomposition, and possibly making the process go anaerobic.
Should this happen air flow can be improved by supporting the heap
on a slatted floor made of up-ended Cuprinol-treated 2 x 4's about
three inches apart tacked into the back wall. Air ducts,
inexpensively made from perforated plastic septic system leach line,
are laid between the slats to greatly enhance air flow. I wouldn't
initially build a bin array with ducted floors; these can be added
as an afterthought if necessary.
Much simpler bins can be constructed out of 2" x 4" mesh x 36" or
48" high strong, welded wire fencing commonly called "turkey wire,"
or "hog wire." The fencing is formed into cylinders four to five
feet in diameter. I think a serious gardener might need one
five-foot circle and two, four-foot diameter ones. Turkey wire is
stiff enough to support itself when formed into a circle by hooking
the fencing upon itself. This home-rolled wire bin system is the
least expensive of all.
As compostable materials are available, the wire circle is gradually
filled. Once the bin has been loaded and has settled somewhat, the
wire may be unhooked and peeled away; the material will hold itself
in a cylindrical shape without further support. After a month or two
the heap will have settled significantly and will be ready to be
turned into a smaller wire cylinder. Again, the material is allowed
to settle and then, if desired, the wire may be removed to be used
again to form another neatly-shaped heap.
Wire-enclosed heaps encourage air circulation, but can also
encourage drying out. Their proper location is in full shade. In
hot, dry climates, moisture retention can be improved by wrapping a
length of plastic sheeting around the outside of the circle and if
necessary, by draping another plastic sheet over the top. However,
doing this limits air flow and prevents removal of the wire support
You may have to experiment with how much moisture-retention the heap
can stand without going anaerobic. To calculate the length of wire
(circumference) necessary to enclose any desired diameter, use the
formula Circumference = Diameter x 3.14. For example, to make a
five-foot circle: 5 x 3.14 = approximately 16 feet of wire.
With the exception of the "tumbler," commercially made compost bins
are derived from one of these two systems. Usually the factory-made
wire bins are formed into rectangles instead of circles and may be
made of PVC coated steel instead of galvanized wire. I see no
advantage in buying a wire bin over making one, other than
supporting unnecessary stages of manufacture and distribution by
spending more money. Turkey wire fencing is relatively inexpensive
and easy enough to find at farm supply and fencing stores. The last
time I purchased any it was sold by the lineal foot much as hardware
cloth is dispensed at hardware and building supply stores.
Manufactured solid-sided bins are usually constructed of sheet steel
or recycled plastic. In cool climates there is an advantage to
tightly constructed plastic walls that retain heat and facilitate
decomposition of smaller thermal masses. Precise construction also
prevents access by larger vermin and pets. Mice, on the other hand,
are capable of squeezing through amazingly small openings.
Promotional materials make composting in pre-manufactured bins seem
easy, self-righteously ecological, and effortless. However, there
It is not possible to readily turn the materials once they've been
placed into most composters of this type unless the entire front is
removable. Instead, new materials are continuously placed on top
while an opening at the bottom permits the gardener to scrape out
finished compost in small quantities. Because no turning is
involved, this method is called "passive" composting. But to work
well, the ingredients must not be too coarse and must be well mixed
Continuous bin composters generally work fast enough when
processing_ mixtures _of readily decomposable materials like kitchen
garbage, weeds, grass clippings and some leaves. But if the load
contains too much fine grass or other gooey stuff and goes
anaerobic, a special compost aerator must be used to loosen it up.
Manufactured passive composters are not very large. Compactness may
be an advantage to people with very small yards or who may want to
compost on their terrace or porch. But if the C/N of the materials
is not favorable, decomposition can take a long, long time and
several bins may have to be used in tandem. Unless they are first
ground or chopped very finely, larger more resistant materials like
corn, Brussels sprouts, sunflower stalks, cabbage stumps, shrub
prunings, etc. will "constipate" a top-loading, bottom-discharging
The compost tumbler is a clever method that accelerates
decomposition by improving aeration and facilitating frequent
turning. A rotating drum holding from eight to eighteen bushels (the
larger sizes look like a squat, fat, oversized oil drum) is
suspended above the ground, top-loaded with organic matter, and then
tumbled every few days for a few weeks until the materials have
decomposed. Then the door is opened and finished compost falls out
Tumblers have real advantages. Frequent turning greatly increases
air supply and accelerates the process. Most tumblers retard
moisture loss too because they are made of solid material, either
heavy plastic or steel with small air vents. Being suspended above
ground makes them immune to vermin and frequent turning makes it
impossible for flies to breed.
Tumblers have disadvantages that may not become apparent until a
person has used one for awhile. First, although greatly accelerated,
composting in them is not instantaneous. Passive bins are continuous
processors while (with the exception of one unique design) tumblers
are "batch" processors, meaning that they are first loaded and then
the entire load is decomposed to finished compost. What does a
person do with newly acquired kitchen garbage and other waste during
the two to six weeks that they are tumbling a batch? One handy
solution is to buy two tumblers and be filling one while the other
is working, but tumblers aren't cheap! The more substantial ones
cost $250 to $400 plus freight.
There are other less obvious tumbler disadvantages that may negate
any work avoided, time saved, or sweaty turning with a manure fork
eliminated. Being top-loaded means lifting compost materials and
dropping them into a small opening that may be shoulder height or
more. These materials may include a sloppy bucket of kitchen
garbage. Then, a tumbler _must_ be tumbled for a few minutes every
two or three days. Cranking the lever or grunting with the barrel
may seem like fun at first but it can get old fast. Decomposition in
an untumbled tumbler slows down to a crawl.
Both the passive compost bin and the highly active compost tumbler
work much better when loaded with small-sized particles. The
purchase of either one tends to impel the gardener to also buy
something to cut and/or grind compost materials.
The U.C. Method--Grinder/Shredders
During the 1950s, mainstream interest in municipal composting
developed in America for the first time. Various industrial
processes already existed in Europe; most of these were patented
variations on large and expensive composting tumblers. Researchers
at the University of California set out to see if simpler methods
could be developed to handle urban organic wastes without investing
in so much heavy machinery. Their best system, named the U. C. Fast
Compost Method, rapidly made compost in about two weeks.
No claim was ever made that U. C. method produces the highest
quality compost. The idea was to process and decompose organic
matter as inoffensively and rapidly as possible. No attempt is made
to maximize the product's C/N as is done in slower methods developed
by Howard at Indore. Most municipal composting done in this country
today follows the basic process worked out by the University of
Speed of decomposition comes about from very high internal heat and
extreme aerobic conditions. To achieve the highest possible
temperature, all of the organic material to be composted is first
passed through a grinder and then stacked in a long, high windrow.
Generally the height is about five to six feet, any higher causes
too much compaction. Because the material is stacked with sides as
vertical as possible, the width takes care of itself.
Frequent turning with machinery keeps the heap working rapidly.
During the initial experiments the turning was done with a tractor
and front end loader. These days giant "U" shaped machines may roll
down windrows at municipal composting plots, automatically turning,
reshaping the windrow and if necessary, simultaneously spraying
Some municipal waste consists of moist kitchen garbage and grass
clippings. Most of the rest is dry paper. If this mixture results in
a moisture content that is too high the pile gets soggy, sags
promptly, and easily goes anaerobic. Turning not only restores
aerobic conditions, but also tends to drop the moisture content. If
the initial moisture content is between 60 and 70 percent, the
windrow is turned every two days. Five such turns, starting two days
after the windrow is first formed, finishes the processing. If the
moisture content is between 10 and 60 percent, the windrow is first
turned after three days and thence at three day intervals, taking
about four turns to finish the process. If the moisture content is
below 40 percent or drops below 40 percent during processing,
moisture is added.
No nuisances can develop if turning is done correctly. Simply
flipping the heap over or adding new material on top will not do it.
The material must be blended so that the outsides are shifted to the
core and the core becomes the skin. This way, any fly larvae,
pathogens, or insect eggs that might not be killed by the cooler
temperatures on the outside are rotated into the lethal high heat of
the core every few days.
The speed of the U.C. method also appeals to the backyard gardener.
At home, frequent turning can be accomplished either in naked heaps,
or by switching from one bin to the next and back, or with a compost
tumbler. But a chipper/shredder is also essential. Grinding
everything that goes into the heap has other advantages than higher
heat and accelerated processing. Materials may be initially mixed as
they are ground and small particles are much easier to turn over
than long twigs, tough straw, and other fibrous materials that tie
the heap together and make it difficult to separate and handle with
Backyard shredders have other uses, especially for gardeners with no
land to waste. Composting tough materials like grape prunings, berry
canes, and hedge trimmings can take a long time. Slow heaps
containing resistant materials occupy precious space. With a
shredder you can fast-compost small limbs, tree prunings, and other
woody materials like corn and sunflower stalks. Whole autumn leaves
tend to compact into airless layers and decompose slowly, but dry
leaves are among the easiest of all materials to grind. Once smashed
into flakes, leaves become a fluffy material that resists
Electric driven garden chipper/shredders are easier on the
neighbors' ears than more powerful gasoline-powered machines,
although not so quiet that I'd run one without ear protection.
Electrics are light enough for a strong person to pick up and carry
out to the composting area and keep secured in a storeroom. One more
plus, there never is any problem starting an electric motor. But no
way to conveniently repair one either.
There are two basic shredding systems. One is the hammermill--a
grinding chamber containing a rotating spindle with steel tines or
hammers attached that repeatedly beats and tears materials into
smaller and smaller pieces until they fall out through a bottom
screen. Hammermills will flail almost anything to pieces without
becoming dulled. Soft, green materials are beaten to shreds; hard,
dry, brittle stuff is rapidly fractured into tiny chips. Changing
the size of the discharge screen adjusts the size of the final
product. By using very coarse screens, even soft, wet, stringy
materials can be slowly fed through the grinding chamber without
hopelessly tangling up in the hammers.
Like a coarse power planer in a wood shop, the other type of machine
uses sharpened blades that slice thin chips from whatever is pushed
into its maw. The chipper is designed to grind woody materials like
small tree limbs, prunings, and berry canes. Proper functioning
depends on having sharp blades. But edges easily become dulled and
require maintenance. Care must be taken to avoid passing soil and
small stones through a chipper. Soft, dry, brittle materials like
leaves will be broken up but aren't processed as rapidly as in a
hammermill. Chippers won't handle soft wet stuff.
When driven by low horsepower electric motors, both chippers and
hammermills are light-duty machines. They may be a little shaky,
standing on spindly legs or small platforms, so materials must be
fed in gently. Most electric models cost between $300 and $400.
People with more than a postage-stamp yard who like dealing with
machinery may want a gasoline-powered shredder/chipper. These are
much more substantial machines that combine both a big hammermill
shredder with a side-feeding chipper for limbs and branches.
Flailing within a hammermill or chipping limbs of two or more inches
in diameter focuses a great deal of force; between the engine noise
and the deafening din as dry materials bang around the grinding
chamber, ear protection is essential. So are safety goggles and
heavy gloves. Even though the fan belt driving the spindle is
shielded, I would not operate one without wearing tight-fitting
clothes. When grinding dry materials, great clouds of dust may be
given off. Some of these particles, like the dust from alfalfa or
from dried-out spoiled (moldy) hay, can severely irritate lungs,
eyes, throat and nasal passages. A face mask, or better, an army
surplus gas mask with built-in goggles, may be in order. And you'll
probably want to take a shower when finished.
Fitted with the right-size screen selected from the assortment
supplied at purchase, something learned after a bit of experience,
powerful hammermills are capable of pulverizing fairly large amounts
of dry material in short order. But wet stuff is much slower to pass
through and may take a much coarser screen to get out at all.
Changing materials may mean changing screens and that takes a few
minutes. Dry leaves seem to flow through as fast as they can be fed
in. The side-feed auxiliary chippers incorporated into hammermills
will make short work of smaller green tree limbs; but dry, hardened
wood takes a lot longer. Feeding large hard branches too fast can
tear up chipper blades and even break the ball-bearing housings
holding the spindle. Here I speak from experience.
Though advertisements for these machines make them seem effortless
and fast, shredders actually take considerable time, energy, skilled
attention, constant concentration, and experience. When grinding one
must attentively match the inflow to the rate of outflow because if
the hopper is overfilled the tines become snarled and cease to work.
For example, tangling easily can occur while rapidly feeding in thin
brittle flakes of dry spoiled hay and then failing to slow down
while a soft, wet flake is gradually reduced. To clear a snarled
rotor without risking continued attachment of one's own arm, the
motor must be killed before reaching into the hopper and untangling
the tines. To clear badly clogged machines it may also be necessary
to first remove and then replace the discharge screen, something
that takes a few minutes.
There are significant differences in the quality of materials and
workmanship that go into making these machines. They all look good
when freshly painted; it is not always possible to know what you
have bought until a season or two of heavy use has passed. One
tried-and-true aid to choosing quality is to ask equipment rental
businesses what brand their customers are not able to destroy.
Another guide is to observe the brand of gasoline engine attached.
In my gardening career I've owned quite a few gas-powered rotary
tillers and lawnmowers and one eight-horsepower shredder. In my
experience there are two grades of small gasoline
engines--"consumer" and the genuine "industrial." Like all consumer
merchandise, consumer-grade engines are intended to be consumed.
They have a design life of a few hundred hours and then are worn
out. Most parts are made of soft, easily-machined aluminum,
reinforced with small amounts of steel in vital places.
There are two genuinely superior American companies--Kohler and
Wisconsin-that make very durable, long-lasting gas engines commonly
found on small industrial equipment. With proper maintenance their
machines are designed to endure thousands of hours of continuous
use. I believe small gas engines made by Yamaha, Kawasaki, and
especially Honda, are of equal or greater quality to anything made
in America. I suggest you could do worse than to judge how long the
maker expects their shredder/chipper to last by the motor it
Gasoline-powered shredder/chippers cost from $700 to $1,300. Back in
the early 1970s I wore one pretty well out in only one year of
making fast compost for a half-acre Biodynamic French intensive
market garden. When I amortized the cost of the machine into the
value of both the compost and the vegetables I grew with the
compost, and considered the amount of time I spent running the
grinder against the extra energy it takes to turn ordinary slow
compost heaps I decided I would be better off allowing my heaps to
take more time to mature.
Decomposition happens rapidly in a hot compost heap with the main
agents of decay being heat-loving microorganisms. Decomposition
happens slowly at the soil's surface with the main agents of decay
being soil animals. However, if the leaves and forest duff on the
floor of a forest or a thick matted sod are tilled into the topsoil,
decomposition is greatly accelerated.
For two centuries, frontier American agriculture depended on just
such a method. Early pioneers would move into an untouched region,
clear the forest, and plow in millennia of accumulated nutrients
held as biomass on the forest floor. For a few years, perhaps a
decade, or even twenty years if the soil carried a higher level of
mineralization than the average, crops from forest soils grew
magnificently. Then, unless other methods were introduced to rebuild
fertility, yields, crop, animal, and human health all declined. When
the less-leached grassy prairies of what we now call the Midwest
were reached, even greater bounties were mined out for more years
because rich black-soil grasslands contain more mineral nutrients
and sod accumulates far more humus than do forests.
Sheet composting mimics this system while saving a great deal of
effort. Instead of first heaping organic matter up, turning it
several times, carting humus back to the garden, spreading it, and
tilling it in, sheet composting conducts the decomposition process
with far less effort right in the soil needing enrichment.
Sheet composting is the easiest method of all. However, the method
has certain liabilities. Unless the material being spread is pure
manure without significant amounts of bedding, or only fresh spring
grass clippings, or alfalfa hay, the carbon-nitrogen ratio will
almost certainly be well above that of stable humus. As explained
earlier, during the initial stages of decay the soil will be
thoroughly depleted of nutrients. Only after the surplus carbon has
been consumed will the soil ecology and nutrient profile normalize.
The time this will take depends on the nature of the materials being
composted and on soil conditions.
If the soil is moist, airy, and warm and if it already contained
high levels of nutrients, and if the organic materials are not
ligninous and tough and have a reasonable C/N, then sheet composting
will proceed rapidly. If the soil is cold, dry, clayey (relatively
airless) or infertile and/or the organic matter consists of things
like grain straw, paper, or the very worst, barkless sawdust, then
decomposition will be slowed. Obviously, it is not possible to state
with any precision how fast sheet composting would proceed for you.
Autumn leaves usually sheet compost very successfully. These are
gathered, spread over all of the garden (except for those areas
intended for early spring sowing), and tilled in as shallowly as
possible before winter. Even in the North where soil freezes solid
for months, some decomposition will occur in autumn and then in
spring, as the soil warms, composting instantly resumes and is
finished by the time frost danger is over. Sheet composting higher
C/N materials in spring is also workable where the land is not
scheduled for planting early. If the organic matter has a low C/N,
like manure, a tender green manure crop not yet forming seed,
alfalfa hay or grass clippings, quite a large volume of material can
be decomposed by warm soil in a matter of weeks.
However, rotting large quantities of very resistant material like
sawdust can take many months, even in hot, moist soil. Most
gardeners cannot afford to give their valuable land over to being a
compost factory for months. One way to speed the sheet composting of
something with a high C/N is to amend it with a strong nitrogen
source like chicken manure or seed meal. If sawdust is the only
organic matter you can find, I recommend an exception to avoiding
chemical fertilizer. By adding about 80 pounds of urea to each cubic
yard of sawdust, its overall C/N is reduced from 500:1 to about
20:1. Urea is perhaps the most benign of all chemical nitrogen
sources. It does not acidify the soil, is not toxic to worms or
other soil animals or microorganisms, and is actually a synthetic
form of the naturally occurring chemical that contains most of the
nitrogen in animal urine. In that sense, putting urea in soil is not
that different than putting synthetic vitamin C in a human body
Burying kitchen garbage is a traditional form of sheet composting
practiced by row-cropping gardeners usually in mild climates where
the soil does not freeze in winter. Some people use a post hole
digger to make a neat six-to eight-inch diameter hole about eighteen
inches deep between well-spaced growing rows of plants. When the
hole has been filled to within two or three inches of the surface,
it is topped off with soil. Rarely will animals molest buried
garbage, it is safe from flies and yet enough air exists in the soil
for it to rapidly decompose. The local soil ecology and nutrient
balance is temporarily disrupted, but the upset only happens in this
one little spot far enough away from growing plants to have no
Another garbage disposal variation has been called "trench
composting." Instead of a post hole, a long trench about the width
of a combination shovel and a foot deep is gradually dug between row
crops spaced about four feet (or more) apart. As bucket after bucket
of garbage, manure, and other organic matter are emptied into the
trench, it is covered with soil dug from a little further along.
Next year, the rows are shifted two feet over so that crops are sown
above the composted garbage.
Ruth Stout discovered--or at least popularized this new-to-her
method. Mulching may owe some of its popularity to Ruth's possession
of writing talent similar to her brother Rex's, who was a well-known
mid-century mystery writer. Ruth's humorous book, _Gardening Without
Work_ is a fun-to-read classic that I highly recommend if for no
other reason than it shows how an intelligent person can make
remarkable discoveries simply by observing the obvious. However,
like many other garden writers, Ruth Stout made the mistake of
assuming that what worked in her own backyard would be universally
applicable. Mulch gardening does not succeed everywhere.
This easy method mimics decomposition on the forest floor. Instead
of making compost heaps or sheet composting, the garden is kept
thickly covered with a permanent layer of decomposing vegetation.
Year-round mulch produces a number of synergistic advantages. Decay
on the soil's surface is slow but steady and maintains fertility. As
on the forest floor, soil animals and worm populations are high.
Their activities continuously loosen the earth, steadily transport
humus and nutrients deeper into the soil, and eliminate all need for
tillage. Protected from the sun, the surface layers of soil do not
dry out so shallow-feeding species like lettuce and moisture-lovers
like radishes make much better growth. During high summer, mulched
ground does not become unhealthfully heated up either.
The advantages go on. The very top layer of soil directly under the
mulch has a high organic matter content, retaining moisture,
eliminating crusting, and consequently, enhancing the germination of
seeds. Mulchers usually sow in well-separated rows. The gardener
merely rakes back the mulch and exposes a few inches of bare soil,
scratches a furrow, and covers the seed with humusy topsoil. As the
seedlings grow taller and are thinned out, the mulch is gradually
pushed back around them.
Weeds? No problem! Except where germinating seeds, the mulch layer
is thick enough to prevent weed seeds from sprouting. Should a weed
begin showing through the mulch, this is taken as an indication that
spot has become too thinly covered and a flake of spoiled hay or
other vegetation is tossed on the unwanted plant, smothering it.
Oh, how easy it seems! Pick a garden site. If you have a year to
wait before starting your garden do not even bother to till first.
Cover it a foot deep with combinations of spoiled hay, leaves, grass
clippings, and straw. Woody wastes are not suitable because they
won't rot fast enough to feed the soil. Kitchen garbage and manures
can also be tossed on the earth and, for a sense of tidiness,
covered with hay. The mulch smothers the grass or weeds growing
there and the site begins to soften. Next year it will be ready to
If the plot is very infertile to begin with there won't be enough
biological activity or nutrients in the soil to rapidly decompose
the mulch. In that case, to accelerate the process, before first
putting down mulch till in an initial manure layer or a heavy
sprinkling of seed meal. Forever after, mulching materials alone
will be sufficient. Never again till. Never again weed. Never again
fertilize. No compost piles to make, turn, and haul. Just keep your
eye open for spoiled hay and buy a few inexpensive tons of it each
Stout, who discovered mulch gardening in Connecticut where irregular
summer rains were usually sufficient to water a widely-spaced
garden, also mistakenly thought that mulched gardens lost less soil
moisture because the earth was protected from the drying sun and
thus did not need irrigation through occasional drought. I suspect
that drought resistance under mulch has more to do with a plant's
ability to feed vigorously, obtain nutrition, and continue growing
because the surface inches where most of soil nutrients and
biological activities are located, stayed moist. I also suspect that
actual, measurable moisture loss from mulched soil may be greater
than from bare earth. But that's another book I wrote, called
_Gardening Without Irrigation.
Yes, gardening under permanent year-round mulch seems easy, but it
does have a few glitches. Ruth Stout did not discover them because
she lived in Connecticut where the soil freezes solid every winter
and stays frozen for long enough to set back population levels of
certain soil animals. In the North, earwigs and sow bugs (pill bugs)
are frequently found in mulched gardens but they do not become a
serious pest. Slugs are infrequent and snails don't exist. All
thanks to winter.
Try permanent mulch in the deep South, or California where I was
first disappointed with mulching, or the Maritime northwest where I
now live, and a catastrophe develops. During the first year these
soil animals are present but cause no problem. But after the first
mild winter with no population setback, they become a plague. Slugs
(and in California, snails) will be found everywhere, devastating
seedlings. Earwigs and sow bugs, that previously only were seen
eating only decaying mulch, begin to attack plants. It soon becomes
impossible to get a stand of seedlings established. The situation
can be rapidly cured by raking up all the mulch, carting it away
from the garden, and composting it. I know this to be the truth
because I've had to do just that both in California where as a
novice gardener I had my first mulch catastrophes, and then when I
moved to Oregon, I gave mulching another trial with similar sad
Sources for Composters, Grinders and etc.
Shredder/Chippers and other power equipment_
I've been watching this market change rapidly since the early 1970s.
Manufacturers come and go. Equipment is usually ordered direct from
the maker, freight extra. Those interested in large horsepower
shredder/chippers might check the advertisements in garden-related
magazines such as _National Gardening, Organic Gardening, Sunset,
Horticulture, Fine Gardening, Country Living (Harrowsmith), _etc.
Without intending any endorsement or criticism of their products,
two makers that have remained in business since I started gardening
Kemp Company. 160 Koser Road., Lititz, PA 17543. (also compost
Troy-Bilt Manufacturing Company, 102D St. & 9th Ave., Troy, NY 12180
_Mail-order catalog sources of compost containers and garden
Gardens Alive, 5100 Schenley Place, Lawrenceburg, Indiana 47025
Gardener's Supply Company, 128 Intervale Road, Burlington, VT 05401
Ringer Corporation, 9959 Valley View Road, Eden Prairie, MN 55344
Smith & Hawken, 25 Corte Madera, Mill Valley, CA 94941
It was 1952 and Mr. Campbell had a worm bin. This shallow box--about
two feet wide by four feet long--resided under a worktable in the
tiny storeroom/greenhouse adjacent to our grade school science
class. It was full of what looked like black, crumbly soil and
zillions of small, red wiggly worms, not at all like the huge
nightcrawlers I used to snatch from the lawn after dark to take
fishing the next morning. Mr. Campbell's worms were fed used coffee
grounds; the worms in turn were fed to salamanders, to Mr.
Campbell's favorite fish, a fourteen-inch long smallmouth bass named
Carl, to various snakes, and to turtles living in aquariums around
the classroom. From time to time the "soil" in the box was fed to
his lush potted plants.
Mr. Campbell was vermicomposting. This being before the age of
ecology and recycling, he probably just thought of it as raising
live food to sustain his educational menagerie. Though I never had
reason to raise worms before, preparing to write this book perked my
interest in every possible method of composting. Not comfortable
writing about something I had not done, I built a small worm box,
obtained a pound or so of brandling worms, made bedding, added
worms, and began feeding the contents of my kitchen compost bucket
to the box.
To my secret surprise, vermicomposting works just as Mary Appelhof's
book _Worms Eat My Garbage_ said it would. Worm composting is
amazingly easy, although I admit there was a short learning curve
and a few brief spells of sour odors that went away as soon as I
stopped overfeeding the worms. I also discovered that my slapdash
homemade box had to have a drip catching pan beneath it. A friend of
mine, who has run her own in-the-house worm box for years, tells me
that diluting these occasional, insignificant and almost odorless
dark-colored liquid emissions with several parts water makes them
into excellent fertilizer for house plants or garden.
It quickly became clear to me that composting with worms
conveniently solves several recycling glitches. How does a northern
homeowner process kitchen garbage in the winter when the ground and
compost pile are frozen and there is no other vegetation to mix in?
And can an apartment dweller without any other kind of organic waste
except garbage and perhaps newspaper recycle these at home? The
solution to both situations is vermicomposting.
Worm castings, the end product of vermicomposting, are truly the
finest compost you could make or buy. Compared to the volume of
kitchen waste that will go into a worm box, the amount of castings
you end up with will be small, though potent. Apartment dwellers
could use worm castings to raise magnificent house plants or scatter
surplus casts under the ornamentals or atop the lawn around their
buildings or in the local park.
In this chapter, I encourage you to at least try worm composting. I
also answer the questions that people ask the most about using worms
to recycle kitchen garbage. As the ever-enthusiastic Mary Applehof
"I hope it convinces you that you, too, can vermicompost, and that
this simple process with the funny name is a lot easier to do than
you thought. After all, if worms eat my garbage, they will eat
Locating the Worms
The species of worm used for vermicomposting has a number of common
names: red worms, red wigglers, manure worms, or brandling worms.
Redworms are healthy and active as long as they are kept above
freezing and below 85 degree. Even if the air temperature gets above
85 degree, their moist bedding will be cooled by evaporation as long
as air circulation is adequate. They are most active and will
consume the most waste between 55-77 degree--room temperatures.
Redworms need to live in a moist environment but must breath air
through their skin. Keeping their bedding damp is rarely the
problem; preventing it from becoming waterlogged and airless can be
In the South or along the Pacific coast where things never freeze
solid, worms may be kept outside in a shallow shaded pit (as long as
the spot does not become flooded) or in a box in the garage or
patio. In the North, worms are kept in a container that may be
located anywhere with good ventilation and temperatures that stay
above freezing but do not get too hot. Good spots for a worm box are
under the kitchen sink, in the utility room, or in the basement. The
kitchen, being the source of the worm's food, is the most
convenient, except for the danger of temporary odors.
If you have one, a basement may be the best location because it is
out of the way. While you are learning to manage your worms there
may be occasional short-term odor problems or fruit flies; these
won't be nearly as objectionable if the box is below the house. Then
too, a vermicomposter can only exist in a complex ecology of soil
animals. A few of these may exit the box and be harmlessly found
about the kitchen. Ultra-fastidious housekeepers may find this
objectionable. Basements also tend to maintain a cooler temperature
in summer. However, it is less convenient to take the compost bucket
down to the basement every few days.
Redworms need to breathe oxygen, but in deep containers bedding can
pack down and become airless, temporarily preventing the worms from
eating the bottom material. This might not be so serious because you
will stir up the box from time to time when adding new food. But
anaerobic decomposition smells bad. If aerobic conditions are
maintained, the odor from a worm box is very slight and not
particularly objectionable. I notice the box's odor only when I am
adding new garbage and get my nose up close while stirring the
material. A shallow box will be better aerated because it exposes
much more surface area. Worm bins should be from eight to twelve
I constructed my own box out of some old plywood. A top is not
needed because the worms will not crawl out. In fact, when worm
composting is done outdoors in shallow pits, few redworms exit the
bottom by entering the soil because there is little there for them
to eat. Because air flow is vital, numerous holes between 1/4 and
1/2 inch in diameter should be made in the bottom and the box must
then have small legs or cleats about 1/2 to 3/4 of an inch thick to
hold it up enough to let air flow beneath. Having a drip-catcher--a
large cookie tray works well--is essential. Worms can also be kept
in plastic containers (like dish pans) with holes punched in the
bottom. As this book is being written, one mail-order garden supply
company even sells a tidy-looking 19" by 24" by about 12" deep green
plastic vermicomposting bin with drip pan, lid, and an initial
supply of worms and bedding. If worm composting becomes more
popular, others will follow suit.
Unless you are very strong do not construct a box larger than 2 x 4
feet because they will need to be lifted from time to time. Wooden
boxes should last three or four years. If built of plywood, use an
exterior grade to prevent delamination. It is not advisable to make
containers from rot-resistant redwood or cedar because the natural
oils that prevent rotting also may be toxic to worms. Sealed with
polyurethane, epoxy, or other non-toxic waterproofing material, worm
boxes should last quite a bit longer.
How big a box or how many boxes do you need? Each cubic foot of worm
box can process about one pound of kitchen garbage each week.
Naturally, some weeks more garbage will go into the box than others.
The worms will adjust to such changes. You can estimate box size by
a weekly average amount of garbage over a three month time span. My
own home-garden-supplied kitchen feeds two "vegetableatarian"
adults. Being year-round gardeners, our kitchen discards a lot of
trimmings that would never leave a supermarket and we throw out as
"old," salad greens that are still fresher than most people buy in
the store. I'd say our 2-1/2 gallon compost bucket is dumped twice a
week in winter and three times in summer. From May through September
while the garden is "on," a single, 2 foot x 4 foot by 12 inch tall
(8 cubic foot) box is not enough for us.
Bedding is a high C/N material that holds moisture, provides an
aerobic medium worms can exist in, and allows you to bury the
garbage in the box. The best beddings are also light and airy,
helping to maintain aerobic conditions. Bedding must not be toxic to
worms because they'll eventually eat it. Bedding starts out dry and
must be first soaked in water and then squeezed out until it is
merely very damp. Several ordinary materials make fine bedding. You
may use a single material bedding or may come to prefer mixtures.
If you have a power shredder, you can grind corrugated cardboard
boxes. Handling ground up cardboard indoors may be a little dusty
until you moisten it. Shredded cardboard is sold in bulk as
insulation but this material has been treated with a fire retardant
that is toxic. Gasoline-powered shredders can also grind up cereal
straw or spoiled grass hay (if it is dry and brittle). Alfalfa hay
will decompose too rapidly.
Similarly, shredded newsprint makes fine bedding. The ink is not
toxic, being made from carbon black and oil. By tearing with the
grain, entire newspaper sections can rapidly be ripped into
inch-wide shreds by hand. Other shredded paper may be available from
banks, offices, or universities that may dispose of documents.
Ground-up leaves make terrific bedding. Here a power shredder is not
necessary. An ordinary lawnmower is capable of chopping and bagging
large volumes of dry leaves in short order. These may be prepared
once a year and stored dry in plastic garbage bags until needed. A
few 30-gallon bags will handle your vermicomposting for an entire
year. However, dry leaves may be a little slower than other
materials to rehydrate.
Peat moss is widely used as bedding by commercial worm growers. It
is very acid and contains other substances harmful to worms that are
first removed by soaking the moss for a few hours and then
hand-squeezing the soggy moss until it is damp. Then a little lime
is added to adjust the pH.
Redworms are heat-tolerant litter dwellers that find little to eat
in soil. Mixing large quantities of soil into worm bedding makes a
very heavy box. However, the digestive system of worms grinds food
using soil particles as the abrasive grit in the same way birds
"chew" in their crop. A big handful of added soil will improve a
worm box. A couple of tablespoonfuls of powdered agricultural lime
does the same thing while adding additional calcium to nourish the
The scientific name of the species used in vermicomposting is
_Eisenia foetida._ They may be purchased by mail from breeders, from
bait stores, and these days, even from mail-order garden supply
companies. Redworms may also be collected from compost and manure
piles after they have heated and are cooling.
Nightcrawlers and common garden worms play a very important part in
the creation and maintenance of soil fertility. But these species
are soil dwellers that require cool conditions. They cannot survive
in a shallow worm box at room temperatures.
Redworms are capable of very rapid reproduction at room temperatures
in a worm box. They lay eggs encased in a lemon-shaped cocoon about
the size of a grain of rice from which baby worms will hatch. The
cocoons start out pearly white but as the baby worms develop over a
three week period, the eggs change color to yellow, then light
brown, and finally are reddish when the babies are ready to hatch.
Normally, two or three young worms emerge from a cocoon.
Hatchlings are whitish and semi-transparent and about one-half inch
long. It would take about 150,000 hatchlings to weigh one pound. A
redworm hatchling will grow at an explosive rate and reach sexual
maturity in four to six weeks. Once it begins breeding a redworm
makes two to three cocoons a week for six months to a year; or, one
breeding worm can make about 100 babies in six months. And the
babies are breeding about three months after the first eggs are
Though this reproductive rate is not the equal of yeast (capable of
doubling every twenty minutes), still a several-hundred-fold
increase every six months is amazingly fast. When vermicomposting,
the worm population increase is limited by available food and space
and by the worms' own waste products or casts. Worm casts are
slightly toxic to worms. When a new box starts out with fresh
bedding it contains no casts. As time goes on, the bedding is
gradually broken down by cellulose-eating microorganisms whose decay
products are consumed by the worms and the box gradually fills with
As the proportion of casts increases, reproduction slows, and mature
worms begin to die. However, you will almost never see a dead worm
in a worm box because their high-protein bodies are rapidly
decomposed. You will quickly recognize worm casts. Once the bedding
has been consumed and the box contains only worms, worm casts, and
fresh garbage it is necessary to empty the casts, replace the
bedding, and start the cycle over. How to do this will be explained
in a moment. But first, how many worms will you need to begin
You could start with a few dozen redworms, patiently begin by
feeding them tiny quantities of garbage and in six months to a year
have a box full. However, you'll almost certainly want to begin with
a system that can consume all or most of your kitchen garbage right
away. So for starters you'll need to obtain two pounds of worms for
each pound of garbage you'll put into the box each day. Suppose in
an average week your kitchen compost bucket takes in seven pounds of
waste or about one gallon. That averages one pound per day. You'll
need about two pounds of worms.
You'll also need a box that holds six or seven cubic feet, or about
2 x 3 feet by 12 inches deep. Each pound of worms needs three or
four cubic feet of bedding. A better way to estimate box size is to
figure that one cubic foot of worm bin can digest about one pound of
kitchen waste a week without going anaerobic and smelling bad.
Redworms are small and consequently worm growers sell them by the
pound. There are about 1,000 mature breeders to the pound of young
redworms. Bait dealers prefer to sell only the largest sizes or
their customers complain. "Red wigglers" from a bait store may only
count 600 to the pound. Worm raisers will sell "pit run" that costs
much less. This is a mix of worms of all sizes and ages. Often the
largest sizes will have already been separated out for sale as fish
bait. That's perfectly okay. Since hatchlings run 150,000 to the
pound and mature worms count about 600-700, the population of a
pound of pit run can vary greatly. A reasonable pit run estimate is
2,000 to the pound.
Actually it doesn't matter what the number is, it is their weight
that determines how much they'll eat. Redworms eat slightly more
than their weight in food every day. If that is so, why did I
recommend first starting vermicomposting with two pounds of worms
for every pound of garbage? Because the worms you'll buy will not be
used to living in the kind of bedding you'll give them nor adjusted
to the mix of garbage you'll feed them. Initially there may be some
losses. After a few weeks the surviving worms will have adjusted.
Most people have little tolerance for outright failure. But if they
have a record of successes behind them, minor glitches won't stop
them. So it is vital to start with enough worms. The _only time
vermicomposting becomes odoriferous is when the worms are fed too
much._ If they quickly eat all the food that they are given the
system runs remarkably smoothly and makes no offense. Please keep
that in mind since there may well be some short-lived problems until
you learn to gauge their intake.
Setting Up a Worm Box
Redworms need a damp but not soggy environment with a moisture
content more or less 75 percent by weight. But bedding material
starts out very dry. So weigh the bedding and then add three times
that weight of water. The rule to remember here is "a pint's a pound
the world 'round," or one gallon of water weighs about eight pounds.
As a gauge, it takes 1 to 1-1/2 pounds of dry bedding for each cubic
foot of box.
Preparing bedding material can be a messy job The best container is
probably an empty garbage can, though in a pinch it can be done in a
kitchen sink or a couple of five gallon plastic buckets. Cautiously
put half the (probably dusty) bedding in the mixing container. Add
about one-half the needed water and mix thoroughly. Then add two
handfuls of soil, the rest of the bedding, and the balance of the
water. Continue mixing until all the water has been absorbed. Then
spread the material evenly through your empty worm box. If you've
measured correctly no water should leak out the bottom vent holes
and the bedding should not drip when a handful is squeezed
Then add the worms. Spread your redworms over the surface of the
bedding. They'll burrow under the surface to avoid the light and in
a few minutes will be gone. Then add garbage. When you do this the
first time, I suggest that you spread the garbage over the entire
surface and mix it in using a three-tined hand cultivator. This is
the best tool to work the box with because the rounded points won't
Then cover the box. Mary Applehof suggests using a black plastic
sheet slightly smaller than the inside dimensions of the container.
Black material keeps out light and allows the worms to be active
right on the surface. You may find that a plastic covering retains
too much moisture and overly restricts air flow. When I covered my
worm box with plastic it dripped too much. But then, most of what I
feed the worms is fresh vegetable material that runs 80-90 percent
water. Other households may feed dryer material like stale bread and
leftovers. I've found that on our diet it is better to keep the box
in a dimly lit place and to use a single sheet of newspaper folded
to the inside dimensions of the box as a loose cover that encourages
aeration, somewhat reduces light on the surface, and lessens
moisture loss yet does not completely stop it.
Feeding the Worms
Redworms will thrive on any kind of vegetable waste you create while
preparing food. Here's a partial list to consider: potato peelings,
citrus rinds, the outer leaves of lettuce and cabbage, spinach
stems, cabbage and cauliflower cores, celery butts, plate scrapings,
spoiled food like old baked beans, moldy cheese and other leftovers,
tea bags, egg shells, juicer pulp. The worms' absolute favorite
seems to be used coffee grounds though these can ferment and make a
Drip coffee lovers can put the filters in too. This extra paper
merely supplements the bedding. Large pieces of vegetable matter can
take a long time to be digested. Before tossing cabbage or
cauliflower cores or celery butts into the compost bucket, cut them
up into finer chunks or thin slices. It is not necessary to grind
the garbage. Everything will break down eventually.
Putting meat products into a worm box may be a mistake. The odors
from decaying meat can be foul and it has been known to attract mice
and rats. Small quantities cut up finely and well dispersed will
digest neatly. Bones are slow to decompose in a worm box. If you
spread the worm casts as compost it may not look attractive
containing whitened, picked-clean bones. Chicken bones are soft and
may disappear during vermicomposting. If you could grind bones
before sending them to the worm bin, they would make valuable
additions to your compost. Avoid putting non-biodegradable items
like plastic, bottle caps, rubber bands, aluminum foil, and glass
into the worm box.
Do not let your cat use the worm bin as a litter box.. The odor of
cat urine would soon become intolerable while the urine is so high
in nitrogen that it might kill some worms. Most seriously, cat
manure can transmit the cysts of a protozoan disease organism called
_Toxoplasma gondii,_ although most cats do not carry the disease.
These parasites may also be harbored in adult humans without them
feeling any ill effects. However, transmitted from mother to
developing fetus, _Toxoplasma gondii _can cause brain damage. You
are going to handle the contents of your worm bin and won't want to
take a chance on being infected with these parasites.
Most people use some sort of plastic jar, recycled half-gallon
yogurt tub, empty waxed paper milk carton, or similar thing to hold
kitchen garbage. Odors develop when anaerobic decomposition begins.
If the holding tub is getting high, don't cover it, feed it to the
It is neater to add garbage in spots rather than mixing it
throughout the bin. When feeding garbage into the worm bin, lift the
cover, pull back the bedding with a three-tine hand cultivator, and
make a hole about the size of your garbage container. Dump the waste
into that hole and cover it with an inch or so of bedding. The whole
operation only takes a few minutes. A few days later the kitchen
compost bucket will again be ready. Make and fill another hole
adjacent to the first. Methodically go around the box this way. By
the time you get back to the first spot the garbage will have become
unrecognizable, the spot will seem to contain mostly worm casts and
bedding, and will not give off strongly unpleasant odors when
On festive occasions, holidays, and during canning season it is easy
to overload the digestive capacity of a worm bin. The problem will
correct itself without doing anything but you may not be willing to
live with anaerobic odors for a week or two. One simple way to
accelerate the "healing" of an anaerobic box is to fluff it up with
your hand cultivator.
Vegetableatarian households greatly increase the amount of organic
waste they generate during summer. So do people who can or freeze
when the garden is "on." One vermicomposting solution to this
seasonal overload is to start up a second, summertime-only outdoor
worm bin in the garage or other shaded location. Appelhof uses an
old, leaky galvanized washtub for this purpose. The tub gets a few
inches of fresh bedding and then is inoculated with a gallon of
working vermicompost from the original bin. Extra garbage goes in
all summer. Mary says:
"I have used for a "worm bin annex" an old leaky galvanized washtub,
kept outside near the garage. During canning season the grape pulp,
corn cobs, corn husks, bean cuttings and other fall harvest residues
went into the container. It got soggy when it rained and the worms
got huge from all the food and moisture. We brought it inside at
about the time of the first frost. The worms kept working the
material until there was no food left. After six to eight months,
the only identifiable remains were a few corn cobs, squash seeds,
tomato skins and some undecomposed corn husks. The rest was an
excellent batch of worm castings and a very few hardy,
Going away from home for a few weeks is not a problem. The worms
will simply continue eating the garbage left in the bin. Eventually
their food supply will decline enough that the population will drop.
This will remedy itself as soon as you begin feeding the bin again.
If a month or more is going to pass without adding food or if the
house will be unheated during a winter "sabbatical," you should give
your worms to a friend to care for.
Fruit flies can, on occasion, be a very annoying problem if you keep
the worm bins in your house. They will not be present all the time
nor in every house at any time but when they are present they are a
nuisance. Fruit flies aren't unsanitary, they don't bite or seek out
people to bother. They seek out over-ripe fruit and fruit pulp.
Usually, fruit flies will hover around the food source that
interests them. In high summer we have accepted having a few share
our kitchen along with the enormous spread of ripe and ripening
tomatoes atop the kitchen counter. When we're making fresh "V-7"
juice on demand throughout the day, they tend to congregate over the
juicer's discharge pail that holds a mixture of vegetable pulps. If
your worm bin contains these types of materials, fruit flies may
find it attractive.
Appelhof suggests sucking them up with a vacuum cleaner hose if
their numbers become annoying. Fruit flies are a good reason for
those of Teutonic tidiness to vermicompost in the basement or
outside the house if possible.
After a new bin has been running for a few weeks, you'll see the
bedding becoming darker and will spot individual worm casts. Even
though food is steadily added, the bedding will gradually vanish.
Extensive decomposition of the bedding by other small soil animals
and microorganisms begins to be significant.
As worm casts become a larger proportion of the bin, conditions
deteriorate for the worms. Eventually the worms suffer and their
number and activity begins to drop off. Differences in bedding,
temperature, moisture, and the composition of your kitchen's garbage
will control how long it takes but eventually you must separate the
worms from their castings and put them into fresh bedding. If you're
using vermicomposting year-round, it probably will be necessary to
regenerate the box about once every four months.
There are a number of methods for separating redworms from their
_Hand sorting_ works well after a worm box has first been allowed to
run down a bit. The worms are not fed until almost all their food
has been consumed and they are living in nearly pure castings. Then
lay out a thick sheet of plastic at least four feet square on the
ground, floor, or on a table and dump the contents of the worm box
Make six to nine cone-shaped piles. You'll see worms all over. If
you're working inside, make sure there is bright light in the room.
The worms will move into the center of each pile. Wait five minutes
or so and then delicately scrape off the surface of each conical
heap, one after another. By the time you finish with the last pile
the worms will have retreated further and you can begin with the
first heap again.
You repeat this procedure, gradually scraping away casts until there
is not much left of the conical heaps. In a surprisingly short time,
the worms will all be squirming in the center of a small pile of
castings. There is no need to completely separate the worms from all
the castings. You can now gather up the worms and place them in
fresh bedding to start anew without further inconvenience for
another four months. Use the vermicompost on house plants, in the
garden, or save it for later.
Hand sorting is particularly useful if you want to give a few pounds
of redworms to a friend.
_Dividing the box_ is another, simpler method. You simply remove
about two-thirds of the box's contents and spread it on the garden.
Then refill the box with fresh bedding and distribute the remaining
worms, castings, and food still in the box. Plenty of worms and egg
cocoons will remain to populate the box. The worms that you dumped
on the garden will probably not survive there.
A better method of dividing a box prevents wasting so many worms.
All of the box's contents are pushed to one side, leaving one-third
to one-half of the box empty. New bedding and fresh food are put on
the "new" side. No food is given to the "old" side for a month or
so. By that time virtually all the worms will have migrated to the
"new" side. Then the "old" side may be emptied and refilled with
People in the North may want to use a worm box primarily in winter
when other composting methods are inconvenient or impossible. In
this case, start feeding the bin heavily from fall through spring
and then let it run without much new food until mid-summer. By that
time there will be only a few worms left alive in a box of castings.
The worms may then be separated from their castings, the box
recharged with bedding and the remaining worms can be fed just
enough to increase rapidly so that by autumn there will again be
enough to eat all your winter garbage.
Garbage Can Composting
Here's a large-capacity vermicomposting system for vegetableatarians
and big families. It might even have sufficient digestive capacity
for serious juice makers. You'll need two or three, 20 to 30 gallon
garbage cans, metal or plastic. In two of them drill numerous
half-inch diameter holes from bottom to top and in the lid as well.
The third can is used as a tidy way to hold extra dry bedding.
Begin the process with about 10 inches of moist bedding material and
worms on the bottom of the first can. Add garbage on top without
mixing it in and occasionally sprinkle a thin layer of fresh
Eventually the first can will be full though it will digest hundreds
of gallons of garbage before that happens. When finally full, the
bulk of its contents will be finished worm casts and will contain
few if any worms. Most of the remaining activity will be on the
surface where there is fresh food and more air. Filling the first
can may take six months to a year. Then, start the second can by
transferring the top few inches of the first, which contains most of
the worms, into a few inches of fresh bedding on the bottom of the
second can. I'd wait another month for the worms left in the initial
can to finish digesting all the remaining garbage. Then, you have 25
to 30 gallons of worm casts ready to be used as compost.
Painting the inside of metal cans with ordinary enamel when they
have been emptied will greatly extend their life. Really high-volume
kitchens might run two vermicomposting garbage cans at once.
Composting For The Food Gardener
There is a great deal of confusion in the gardening world about
compost, organic matter, humus, fertilizer and their roles in soil
fertility, plant health, animal health, human health and gardening
success. Some authorities seem to recommend as much manure or
compost as possible. Most show inadequate concern about its quality.
The slick books published by a major petrochemical corporation
correctly acknowledge that soil organic matter is important but give
rather vague guidelines as to how much while focusing on chemical
fertilizers. Organic gardeners denigrate chemicals as though they
were of the devil and like J.I. Rodale in _The Organic Front,_
"Is it practical to run a garden exclusively with the use of
compost, without the aid of so-called chemical or artificial
fertilizers? The answer is not only _yes,_ but in such case you will
have the finest vegetables obtainable, vegetables fit to grace the
table of the most exacting gourmet."
Since the 1950s a government-funded laboratory at Cornell University
has cranked out seriously flawed studies "proving" that food raised
with chemicals is just as or even more nutritious than organically
grown food. The government's investment in "scientific research" was
made to counter unsettling (to various economic interest groups)
nutritional and health claims that the organic farming movement had
been making. For example, in _The Living Soil,_ Lady Eve Balfour
"I have lived a healthy country existence practically all my life,
and for the last 25 years of it I have been actively engaged in
farming. I am physically robust, and have never suffered a major
illness, but until 1938 I was seldom free in winter from some form
of rheumatism, and from November to April I invariably suffered from
a continual succession of head colds. I started making compost by
Howard's method using it first on the vegetables for home
consumption.... That winter I had no colds at all and almost for the
first time in my life was free from rheumatic pains even in
prolonged spells of wet weather."
Fifty years later there still exists an intensely polarized dispute
about the right way to garden and farm. People who are comfortable
disagreeing with Authority and that believe there is a strong
connection between soil fertility and the consequent health of
plants, animals, and humans living on that soil tend to side with
the organic camp. People who consider themselves "practical" or
scientific tend to side with the mainstream agronomists and consider
chemical agriculture as the only method that can produce enough to
permit industrial civilization to exist. For many years I was
confused by all this. Have you been too? Or have you taken a
position on this controversy and feel that you don't need more
information? I once thought the organic camp had all the right
answers but years of explaining soil management in gardening books
made me reconsider and reconsider again questions like "why is
organic matter so important in soil?" and "how much and what kind do
we need?" I found these subjects still needed to have clearer
answers. This book attempts to provide those answers and puts aside
A Brief History of the Organic Movement
How did all of this irresolvable controversy begin over something
that should be scientifically obvious? About 1900, "experts"
increasingly encouraged farmers to use chemical fertilizers and to
neglect manuring and composting as unprofitable and unnecessary. At
the time this advice seemed practical because chemicals did greatly
increase yields and profits while chemistry plus motorized farm
machinery minus livestock greatly eased the farmer's workload,
allowed the farmer to abandon the production of low-value fodder
crops, and concentrate on higher value cash crops.
Perplexing new farming problems--diseases, insects and loss of seed
vigor--began appearing after World War 1. These difficulties did not
seem obviously connected to industrial agriculture, to abandonment
of livestock, manuring, composting, and to dependence on chemistry.
The troubled farmers saw themselves as innocent victims of
happenstance, needing to hire the chemical plant doctor much as sick
people are encouraged by medical doctors to view themselves as
victims, who are totally irresponsible for creating their condition
and incapable of curing it without costly and dangerous medical
Farming had been done holistically since before Roman times. Farms
inevitably included livestock, and animal manure or compost made
with manure or green manures were the main sustainers of soil
fertility. In 1900 productive farm soils still contained large
reserves of humus from millennia of manuring. As long as humus is
present in quantity, small, affordable amounts of chemicals actually
do stimulate growth, increase yields, and up profits. And plant
health doesn't suffer nor do diseases and insects become plagues.
However, humus is not a permanent material and is gradually
decomposed. Elimination of manuring steadily reduced humus levels
and consequently decreased the life in the soil. And (as will be
explained a little later) nitrogen-rich fertilizers accelerate humus
With the decline of organic matter, new problems with plant and
animal health gradually developed while insect predation worsened
and profits dropped because soils declining in humus need ever
larger amounts of fertilizer to maintain yields. These changes
developed gradually and erratically, and there was a long lag
between the first dependence on chemicals, the resulting soil
addiction, and steady increases in farm problems. A new alliance of
scientific experts, universities, and agribusiness interests had
self-interested reasons to identify other causes than loss of soil
humus for the new problems. The increasingly troubled farmer's
attention was thus fixated on fighting against plant and animal
diseases and insects with newer and better chemicals.
Just as with farm animals, human health also responds to soil
fertility. Industrial agriculture steadily lowered the average
nutritional quality of food and gradually increased human
degeneration, but these effects were masked by a statistical
increase in human life span due to improved public sanitation,
vaccinations, and, starting in the 1930s, the first antibiotics. As
statistics, we were living longer but as individuals, we were
feeling poorer. Actually, most of the statistical increase in
lifespan is from children that are now surviving childhood diseases.
I contend that people who made it to seven years old a century ago
had a chance more-or-less equal to ours, of surviving past seventy
with a greater probability of feeling good in middle-and old age.
People have short memories and tend to think that things always were
as they are in the present. Slow but continuous increases in
nutritionally related diseases like tooth decay, periodontal
disease, diabetes, heart disease, birth defects, mental retardation,
drug addiction or cancer are not generally seen as a "new" problem,
while subtle reductions in the feeling of well-being go unnoticed.
During the 1930s a number of far-seeing individuals began to worry
about the social liabilities from chemically dependent farming. Drs.
Robert McCarrison and Weston Price addressed their concerns to other
health professionals. Rudolf Steiner, observing that declines in
human health were preventing his disciples from achieving spiritual
betterment started the gentle biodynamic farming movement. Steiner's
principal English speaking followers, Pfeiffer and Koepf, wrote
about biological farming and gardening extensively and well.
Professor William Albrecht, Chairman of the Soil Department of the
University of Missouri, tried to help farmers raise healthier
livestock and made unemotional but very explicit connections between
soil fertility, animal, and human health. Any serious gardener or
person interested in health and preventive medicine will find the
books of all these unique individuals well worth reading.
I doubt that the writings and lectures of any of the above
individuals would have sparked a bitter controversy like the
intensely ideological struggle that developed between the organic
gardening and farming movement and the agribusiness establishment.
This was the doing of two energetic and highly puritanical men: Sir
Albert Howard and his American disciple, J.I. Rodale.
Howard's criticism was correctly based on observations of improved
animal and human health as a result of using compost to build soil
fertility. Probably concluding that the average farmer's weak
ethical condition would be unable to resist the apparently
profitable allures of chemicals unless their moral sense was
outraged, Howard undertook an almost religious crusade against the
evils of chemical fertilizers. Notice the powerful emotional loading
carried in this brief excerpt from Howard's _Soil and Health:_
"Artificial fertilizers lead to artificial nutrition, artificial
animals and finally to artificial men and women."
Do you want to be "artificial?" Rodale's contentious _Organic Front
_makes readers feel morally deficient if they do not agree about the
vital importance of recycling organic matter.
"The Chinese do not use chemical fertilizers. They return to the
land every bit of organic matter they can find. In China if you
burned over a field or a pile of vegetable rubbish you would be
severely punished. There are many fantastic stories as to the
lengths the Chinese will go to get human excremental matter. A
traveler told me that while he was on the toilet in a Shanghai hotel
two men were waiting outside to rush in and make way with the
Perhaps you too should be severely punished for wasting your
personal organic matter.
Rodale began proselytizing for the organic movement about 1942. With
an intensity unique to ideologues, he attacked chemical companies,
attacked chemical fertilizers, attacked chemical pesticides, and
attacked the scientific agricultural establishment. With a limited
technical education behind him, the well-meaning Rodale occasionally
made overstatements, wrote oversimplification as science, and
uttered scientific absurdities as fact. And he attacked, attacked,
attacked all along a broad organic front. So the objects of his
attacks defended, defended, defended.
A great deal of confusion was generated from the contradictions
between Rodale's self-righteous and sometimes scientifically vague
positions and the amused defenses of the smug scientific community.
Donald Hopkins' _Chemicals, Humus and the Soil_ is the best, most
humane, and emotionally generous defense against the extremism of
Rodale. Hopkins makes hash of many organic principles while still
upholding the vital role of humus. Anyone who thinks of themselves
as a supporter of organic farming and gardening should first dig up
this old, out-of-print book, and come to terms with Hopkins'
Organic versus establishment hostilities continued unabated for many
years. After his father's death, Rodale's son and heir to the
publishing empire, Robert, began to realize that there was a
sensible middle ground. However, I suppose Robert Rodale perceived
communicating a less ideological message as a problem: most of the
readers of _Organic Gardening and Farming _magazine and the buyers
of organic gardening books published by Rodale Press weren't open to
I view organic gardeners largely as examples of American Puritanism
who want to possess an clear, simple system of capital "T" truth,
that brooks no exceptions and has no complications or gray areas.
"Organic" as a movement had come to be defined by Rodale
publications as growing food by using an approved list of substances
that were considered good and virtuous while shunning another list
that seemed to be considered 'of the devil,' similar to kosher and
non-kosher food in the orthodox Jewish religion. And like other
puritans, the organic faithful could consider themselves superior
But other agricultural reformers have understood that there _are_
gray areas--that chemicals are not all bad or all good and that
other sane and holistic standards can be applied to decide what is
the best way to go about raising crops. These people began to
discuss new agricultural methods like Integrated Pest Management
[IPM] or Low Input Sustainable Agriculture [LISA], systems that
allowed a minimal use of chemistry without abandoning the focus on
soil organic matter's vital importance.
My guess is that some years back, Bob Rodale came to see the truth
of this, giving him a problem--he did not want to threaten a major
source of political and financial support. So he split off the
"farming" from _Organic Gardening and Farming _magazine and started
two new publications, one called _The New Farm_ where safely away
from less educated unsophisticated eyes he could discuss minor
alterations in the organic faith without upsetting the readers of
I have offered this brief interpretation of the organic gardening
and farming movement primarily for the those gardeners who, like me,
learned their basics from Rodale Press. Those who do not now cast
this heretical book down in disgust but finish it will come away
with a broader, more scientific understanding of the vital role of
organic matter, some certainty about how much compost you really
need to make and use, and the role that both compost and fertilizers
can have in creating and maintaining the level of soil fertility
needed to grow a great vegetable garden.
Humus and Soil Productivity
Books about hydroponics sound plausible. That is, until you actually
_see_ the results. Plants grown in chemical nutrient solutions may
be huge but look a little "off." Sickly and weak somehow. Without a
living soil, plants can not be totally healthy or grow quite as well
as they might.
By focusing on increasing and maximizing soil life instead of adding
chemical fertility, organic farmers are able to grow excellent
cereals and fodder. On richer soils they can even do this for
generations, perhaps even for millennia without bringing in plant
nutrients from elsewhere. If little or no product is sent away from
the farm, this subsistence approach may be a permanent agricultural
system. But even with a healthy ecology few soils are fertile enough
by themselves to permit continuous export of their mineral resources
by selling crops at market.
Take one step further. Cereals are mostly derived from hardy grasses
while other field crops have similar abilities to thrive while being
offered relatively low levels of nutrients. With good management,
fertile soils are able to present these lower nutritional levels to
growing plants without amendment or fortification with potent,
concentrated nutrient sources. But most vegetables demand far higher
levels of support. Few soils, even fertile soils that have never
been farmed, will grow vegetables without improvement. Farmers and
gardeners must increase fertility significantly if they want to grow
great vegetables. The choices they make while doing this can have a
strong effect, not only on their immediate success or failure, but
on the actual nutritional quality of the food that they produce.
How Humus Benefits Soil
The roots of plants, soil animals, and most soil microorganisms need
to breathe oxygen. Like other oxygen burners, they expel carbon
dioxide. For all of them to grow well and be healthy, the earth must
remain open, allowing air to enter and leave freely. Otherwise,
carbon dioxide builds up to toxic levels. Imagine yourself being
suffocated by a plastic bag tied around your neck. It would be about
the same thing to a root trying to live in compacted soil.
A soil consisting only of rock particles tends to be airless. A
scientist would say it had a high bulk density or lacked pore space.
Only coarse sandy soil remains light and open without organic
matter. Few soils are formed only of coarse sand, most are mixtures
of sand, silt and clay. Sands are sharp-sided, relatively large rock
particles similar to table salt or refined white sugar. Irregular
edges keep sand particles separated, and allow the free movement of
air and moisture.
Silt is formed from sand that has weathered to much smaller sizes,
similar to powdered sugar or talcum powder. Through a magnifying
lens, the edges of silt particles appear rounded because weak soil
acids have actually dissolved them away. A significant amount of the
nutrient content of these decomposed rock particles has become plant
food or clay. Silt particles can compact tightly, leaving little
space for air.
As soil acids break down silts, the less-soluble portions recombine
into clay crystals. Clay particles are much smaller than silt
grains. It takes an electron microscope to see the flat, layered
structures of clay molecules. Shales and slates are rocks formed by
heating and compressing clay. Their layered fracture planes mimic
the molecules from which they were made. Pure clay is heavy, airless
and a very poor medium for plant growth.
Humusless soils that are mixtures of sand, silt, and clay can become
extremely compacted and airless because the smaller silt and clay
particles sift between the larger sand bits and densely fill all the
pore spaces. These soils can also form very hard crusts that resist
the infiltration of air, rain, or irrigation water and prevent the
emergence of seedlings. Surface crusts form exactly the same way
that concrete is finished.
Have you ever seen a finisher screed a concrete slab? First, smooth
boards and then, large trowels are run back and forth over liquid
concrete. The motion separates the tiny bits of fine sand and cement
from denser bits of gravel. The "fines" rise to the surface where
they are trowelled into a thin smooth skin. The same thing happens
when humusless soil is rained on or irrigated with sprinklers
emitting a coarse, heavy spray. The droplets beat on the soil,
mechanically separating the lighter "fines" (in this case silt and
clay) from larger, denser particles. The sand particles sink, the
fines rise and dry into a hard, impenetrable crust.
Organic matter decomposing in soil opens and loosens soil and makes
the earth far more welcoming to plant growth. Its benefits are both
direct and indirect. Decomposing organic matter mechanically acts
like springy sponges that reduce compaction. However, rotting is
rapid and soon this material and its effect is virtually gone. You
can easily create this type of temporary result by tilling a thick
dusting of peat moss into some poor soil.
A more significant and longer-lasting soil improvement is created by
microorganisms and earthworms, whose activities makes particles of
sand, silt, and clay cling strongly together and form large,
irregularly-shaped grains called "aggregates" or "crumbs" that
resist breaking apart. A well-developed crumb structure gives soil a
set of qualities farmers and gardeners delightfully refer to as
"good tilth." The difference between good and poor tilth is like
night and day to someone working the land. For example, if you
rotary till unaggregated soil into a fluffy seedbed, the first time
it is irrigated, rained on, or stepped on it slumps back down into
an airless mass and probably develops a hard crust as well. However,
a soil with good tilth will permit multiple irrigations and a fair
amount of foot traffic without compacting or crusting.
Crumbs develop as a result of two similar, interrelated processes.
Earthworms and other soil animals make stable humus crumbs as soil,
clay and decomposing organic matter pass through their digestive
systems. The casts or scats that emerge _are crumbs._ Free-living
soil microorganisms also form crumbs. As they eat organic matter
they secrete slimes and gums that firmly cement fine soil particles
together into long lasting aggregates.
I sadly observe what happens when farmers allow soil organic matter
to run down every time I drive in the country. Soil color that
should be dark changes to light because mineral particles themselves
are usually light colored or reddish; the rich black or chestnut
tone soil can get is organic matter. Puddles form when it rains hard
on perfectly flat humusless fields and may stand for hours or days,
driving out all soil air, drowning earthworms, and suffocating crop
roots. On sloping fields the water runs off rather than percolating
in. Evidence of this can be seen in muddy streams and in more severe
cases, by little rills or mini-gullies across the field caused by
fast moving water sweeping up soil particles from the crusted
surface as it leaves the field.
Later, the farmers will complain of drought or infertility and seek
to support their crops with irrigation and chemicals. Actually, if
all the water that had fallen on the field had percolated into the
earth, the crops probably would not have suffered at all even from
extended spells without rain. These same humusless fields lose a lot
more soil in the form of blowing dust clouds when tilled in a dryish
The greatest part of farm soil erosion is caused by failing to
maintain necessary levels of humus. As a nation, America is losing
its best cropland at a nonsustainable rate. No civilization in
history has yet survived the loss of its prime farmland. Before
industrial technology placed thousands of times more force into the
hands of the farmer, humans still managed to make an impoverished
semi-desert out of every civilized region within 1,000-1,500 years.
This sad story is told in Carter and Dale's fascinating, but
disturbing, book called _Topsoil and Civilization _that I believe
should be read by every thoughtful person. Unless we significantly
alter our "improved" farming methods we will probably do the same to
America in another century or two.
The Earthworm's Role in Soil Fertility
Soil fertility has been gauged by different measures. Howard
repeatedly insisted that the only good yardstick was humus content.
Others are so impressed by the earthworm's essential functions that
they count worms per acre and say that this number measures soil
fertility. The two standards of evaluation are closely related.
When active, some species of earthworms daily eat a quantity of soil
equal to their own body weight. After passing through the worm's
gut, this soil has been chemically altered. Minerals, especially
phosphorus which tends to be locked up as insoluble calcium
phosphate and consequently unavailable to plants, become soluble in
the worm's gut, and thus available to nourish growing plants. And
nitrogen, unavailably held in organic matter, is altered to soluble
nitrate nitrogen. In fact, compared to the surrounding soil, worm
casts are five times as rich in nitrate nitrogen; twice as rich in
soluble calcium; contain two and one-half times as much available
magnesium; are seven times as rich in available phosphorus, and
offer plants eleven times as much potassium. Earthworms are equally
capable of making trace minerals available.
Highly fertile earthworm casts can amount to a large proportion of
the entire soil mass. When soil is damp and cool enough to encourage
earthworm activity, an average of 700 pounds of worm casts per acre
are produced each day. Over a year's time in the humid eastern
United States, 100,000 pounds of highly fertile casts per acre may
be generated. Imagine! That's like 50 tons of low-grade fertilizer
per acre per year containing more readily available NPK, Ca, Mg and
so forth, than farmers apply to grow cereal crops like wheat, corn,
or soybeans. A level of fertility that will grow wheat is not enough
nutrition to grow vegetables, but earthworms can make a major
contribution to the garden.
At age 28, Charles Darwin presented "On the Formation of Mould" to
the Geological Society of London. This lecture illustrated the
amazing churning effect of the earthworm on soil. Darwin observed
some chunks of lime that had been left on the surface of a meadow. A
few years later they were found several inches below the surface.
Darwin said this was the work of earthworms, depositing castings
that "sooner or later spread out and cover any object left on the
surface." In a later book, Darwin said,
"The plow is one of the most ancient and most valuable of man's
inventions; but long before he existed the land was in fact
regularly plowed and still continues to be thus plowed by
earthworms. It may be doubted whether there are many other animals
which have played so important a part in the history of the world,
as have these lowly organized creatures."
Earthworms also prevent runoff. They increase percolation of water
into fine-textured soils by making a complex system of
interconnected channels or tunnels throughout the topsoil. In one
study, soil lacking worms had an absorption rate of 0.2 inches of
rainfall per minute. Earthworms were added and allowed to work over
that soil sample for one month. Then, infiltration rates increased
to 0.9 inches of rainfall per minute. Much of what we know about
earthworms is due to Dr. Henry Hopp who worked for the United States
Department of Agriculture during the 1940s. Dr. Hopp's interesting
booklet, _What Every Gardener Should Know About Earthworms._ is
still in print. In one Hopp research project, some very run-down
clay soil was placed in six large flowerpots. Nothing was done to a
pair of control pots, fertilizer was blended in and grass sod grown
on two others, while mulch was spread over two more. Then worms were
added to one of each pair of pots. In short order all of the worms
added to the unimproved pot were dead. There was nothing in that
soil to feed them. The sod alone increased percolation but where the
sod or mulch fed a worm population, infiltration of water was far
Amendment to clay soil Percolation rate in inches per minute
Without worms With worms
None 0.0 0.0
Grass and fertilizer 0.2 0.8
Mulch 0.0 1.5
Most people who honestly consider these facts conclude that the
earthworm's activities are a major factor in soil productivity.
Study after scientific study has shown that the quality and yield of
pastures is directly related to their earthworm count. So it seems
only reasonable to evaluate soil management practices by their
effect on earthworm counts.
Earthworm populations will vary enormously according to climate and
native soil fertility. Earthworms need moisture; few if any will be
found in deserts. Highly mineralized soils that produce a lot of
biomass will naturally have more worms than infertile soils lacking
humus. Dr. Hopp surveyed worm populations in various farm soils. The
table below shows what a gardener might expect to find in their own
garden by contrasting samples from rich and poor soils. The data
also suggest a guideline for how high worm populations might be
usefully increased by adding organic matter. The worms were counted
at their seasonal population peak by carefully examining a section
of soil exactly one foot square by seven inches deep. If you plan to
take a census in your own garden, keep in mind that earthworm counts
will be highest in spring.
Earthworms are inhibited by acid soils and/or soils deficient in
calcium. Far larger populations of worms live in soils that
weathered out of underlying limestone rocks. In one experiment,
earthworm counts in a pasture went up from 51,000 per acre in acid
soil to 441,000 per acre two years after lime and a non-acidifying
chemical fertilizer was spread. Rodale and Howard loudly and
repeatedly contended that chemical fertilizers decimate earthworm
populations. Swept up in what I view as a self-righteous crusade
against chemical agriculture, they included all fertilizers in this
category for tactical reasons.
Location Worms per sq. ft. Worms per acre
Marcellus, NY 38 1,600,000
Ithica, NY 4 190,000
Frederick, MD 50 2,200,000
Beltsville, MD 8 350,000
Zanesville, OH 37 1,600,000
Coshocton, OH 5 220,000
Mayaquez, P.R.* 6 260,000
*Because of the high rate of bacterial decomposition, few earthworms
are found in tropical soils unless they are continuously ammended
with substantial quantities of organic matter.
Howard especially denigrated sulfate of ammonia and single
superphosphate as earthworm poisons. Both of these chemical
fertilizers are made with sulfuric acid and have a powerful
acidifying reaction when they dissolve in soil. Rodale correctly
pointed out that golf course groundskeepers use repeated
applications of ammonium sulfate to eliminate earthworms from
putting greens. (Small mounds of worm casts made by nightcrawlers
ruin the greens' perfectly smooth surface so these worms are the
bane of greenskeepers.) However, ammonium sulfate does not eliminate
or reduce worms when the soil contains large amounts of chalk or
other forms of calcium that counteract acidity.
The truth of the matter is that worms eat decaying organic matter
and any soil amendment that increases plant growth without
acidifying soil will increase earthworm food supply and thus worm
population. Using lime as an antidote to acid-based fertilizers
prevents making the soil inhospitable to earthworms. And many
chemical fertilizers do not provoke acid reactions. The organic
movement loses this round-but not the battle. And certainly not the
Food supply primarily determines earthworm population. To increase
their numbers it is merely necessary to bring in additional organic
matter or add plant nutrients that cause more vegetation to be grown
there. In one study, simply returning the manure resulting from hay
taken off a pasture increased earthworms by one-third. Adding lime
and superphosphate to that manure made an additional improvement of
another 33 percent. Every time compost is added to a garden, the
soil's ability to support earthworms increases.
Some overly enthusiastic worm fanciers believe it is useful to
import large numbers of earthworms. I do not agree. These same
self-interested individuals tend to breed and sell worms. If the
variety being offered is _Eisenia foetida,_ the brandling, red
wiggler, or manure worm used in vermicomposting, adding them to soil
is a complete waste of money. This species does not survive well in
ordinary soil and can breed in large numbers only in decomposing
manure or other proteinaceous organic waste with a low C/N. All worm
species breed prolifically. If there are _any_ desirable worms
present in soil, their population will soon match the available food
supply and soil conditions. The way to increase worm populations is
to increase organic matter, up mineral fertility, and eliminate
Earthworms and their beneficial activities are easily overlooked and
left out of our contemplations on proper gardening technique. But
understanding their breeding cycle allows gardeners to easily assist
the worms efforts to multiply. In temperate climates, young
earthworms hatch out in the fall when soil is cooling and moisture
levels are high. As long as the soil is not too cold they feed
actively and grow. By early spring these young worms are busily
laying eggs. With summer's heat the soil warms and dries out. Even
if the gardener irrigates, earthworms naturally become less active.
They still lay a few eggs but many mature worms die. During high
summer the few earthworms found will be small and young. Unhatched
eggs are plentiful but not readily noticed by casual inspection so
gardeners may mistakenly think they have few worms and may worry
about how to increase their populations. With autumn the population
cycle begins anew.
Soil management can greatly alter worm populations. But, how the
field is handled during summer has only a slight effect. Spring and
summer tillage does kill a few worms but does not damage eggs. By
mulching, the soil can be kept cooler and more favorable to worm
activities during summer while surface layers are kept moister.
Irrigation helps similarly. Doing these things will allow a gardener
the dubious satisfaction of seeing a few more worms during the main
gardening season. However, soil is supposed to become inhospitably
hot and dry during summer (worm's eye view) and there's not much
point in struggling to maintain large earthworm populations during
that part of the year. Unfortunately, summer is when gardeners pay
the closest attention to the soil.
Worms maintain their year-round population by overwintering and then
laying eggs that hatch late in the growing season. The most harm to
worm multiplication happens by exposing bare soil during winter.
Worm activity should be at a peak during cool weather. Though worms
inadvertently pass a lot of soil through their bodies as they
tunnel, soil is not their food. Garden worms and nightcrawlers
intentionally rise to the surface to feed. They consume decaying
vegetation lying on the surface. Without this food supply they die
off. And in northern winters worms must be protected from suddenly
experiencing freezing temperatures while they "harden off" and adapt
themselves to surviving in almost frozen soil. Under sod or where
protected by insulating mulch or a layer of organic debris, soil
temperature drops gradually as winter comes on. But the first day or
two of cold winter weather may freeze bare soil solid and kill off
an entire field full of worms before they've had a chance to adapt.
Almost any kind of ground cover will enhance winter survival. A
layer of compost, manure, straw, or a well-grown cover crop of
ryegrass, even a thin mulch of grass clippings or weeds can serve as
the food source worms need. Dr. Hopp says that soil tilth can be
improved a great deal merely by assisting worms over a single
Gardeners can effectively support the common earthworm without
making great alterations in the way we handle our soil. From a
worm's viewpoint, perhaps the best way to recycle autumn leaves is
to till them in very _shallowly_ over the garden so they serve as
insulation yet are mixed with enough soil so that decomposition is
accelerated. Perhaps a thorough garden clean-up is best postponed
until spring, leaving a significant amount of decaying vegetation on
top of the soil. (Of course, you'll want to remove and compost any
diseased plant material or species that may harbor overwintering
pests.) The best time to apply compost to tilled soil may also be
during the autumn and the very best way is as a dressing atop a leaf
mulch because the compost will also accelerate leaf decomposition.
This is called "sheet composting" and will be discussed in detail
Certain pesticides approved for general use can severely damage
earthworms. Carbaryl (Sevin), one of the most commonly used home
garden chemical pesticides, is deadly to earthworms even at low
levels. Malathion is moderately toxic to worms. Diazinon has not
been shown to be at all harmful to earthworms when used at normal
Just because a pesticide is derived from a natural source and is
approved for use on crops labeled "organically grown" is no
guarantee that it is not poisonous to mammals or highly toxic to
earthworms. For example, rotenone, an insecticide derived from a
tropical root called derris, is as poisonous to humans as
organophosphate chemical pesticides. Even in very dilute amounts,
rotenone is highly toxic to fish and other aquatic life. Great care
must be taken to prevent it from getting into waterways. In the
tropics, people traditionally harvest great quantities of fish by
tossing a handful of powdered derris (a root containing rotenone)
into the water, waiting a few minutes, and then scooping up stunned,
dead, and dying fish by the ton. Rotenone is also deadly to
earthworms. However, rotenone rarely kills worms because it is so
rapidly biodegradable. Sprayed on plants to control beetles and
other plant predators, its powerful effect lasts only a day or so
before sun and moisture break it down to harmless substances. But
once I dusted an entire raised bed of beetle-threatened bush bean
seedlings with powdered rotenone late in the afternoon. The spotted
beetles making hash of their leaves were immediately killed.
Unexpectedly, it rained rather hard that evening and still-active
rotenone was washed off the leaves and deeply into the soil. The
next morning the surface of the bed was thickly littered with dead
earthworms. I've learned to treat rotenone with great caution.
Microbes and Soil Fertility
There are still other holistic standards to measure soil
productivity. With more than adequate justification the great
Russian soil microbiologist N.S. Krasilnikov judged fertility by
counting the numbers of microbes present. He said,
". . soil fertility is determined by biological factors, mainly by
microorganisms. The development of life in soil endows it with the
property of fertility. The notion of soil is inseparable from the
notion of the development of living organisms in it. Soil is created
by microorganisms. Were this life dead or stopped, the former soil
would become an object of geology [not biology]."
Louise Howard, Sir Albert's second wife, made a very similar
judgment in her book, _Sir Albert Howard in India._
"A fertile soil, that is, a soil teeming with healthy life in the
shape of abundant microflora and microfauna, will bear healthy
plants, and these, when consumed by animals and man, will confer
health on animals and man. But an infertile soil, that is, one
lacking in sufficient microbial, fungous, and other life, will pass
on some form of deficiency to the plants, and such plant, in turn,
who pass on some form of deficiency to animal and man."
Although the two quotes substantively agree, Krasilnikov had a
broader understanding. The early writers of the organic movement
focused intently on mycorrhizal associations between soil fungi and
plant roots as _the_ hidden secret of plant health. Krasilnikov,
whose later writings benefited from massive Soviet research did not
deny the significance of mycorrhizal associations but stressed
plant-bacterial associations. Both views contain much truth.
Krasilnikov may well have been the greatest soil microbiologist of
his era, and Russians in general seem far ahead of us in this field.
It is worth taking a moment to ask why that is so. American
agricultural science is motivated by agribusiness, either by direct
subsidy or indirectly through government because our government is
often strongly influenced by major economic interests. American
agricultural research also exists in a relatively free market where
at this moment in history, large quantities of manufactured
materials are reliably and cheaply available. Western agricultural
science thus tends to seek solutions involving manufactured inputs.
After all, what good is a problem if you can't solve it by
profitably selling something.
But any Soviet agricultural researcher who solved problems by using
factory products would be dooming their farmers to failure because
the U.S.S.R.'s economic system was incapable of regularly supplying
such items. So logically, Soviet agronomy focused on more holistic,
low-tech approaches such as manipulating the soil microecology. For
example, Americans scientifically increase soil nitrogen by
spreading industrial chemicals; the Russians found low-tech ways to
brew bacterial soups that inoculated a field with slightly more
efficient nitrogen-fixing microorgamsms.
Soil microbiology is also a relatively inexpensive line of research
that rewards mental cleverness over massive investment. Multimillion
dollar laboratories with high-tech equipment did not yield big
answers when the study was new. Perhaps in this biotech era,
recombinant genetics will find high-tech ways to tailor make
improved microorganisms and we'll surpass the Russians.
Soil microorganism populations are incredibly high. In productive
soils there may be billions to the gram. (One gram of fluffy soil
might fill 1/2 teaspoon.) Krasilnikov found great variations in
bacterial counts. Light-colored nonproductive earths of the North
growing skimpy conifer trees or poor crops don't contain very many
microorganisms. The rich, black, grain-producing soils of the
Ukraine (like our midwestern corn belt) carry very large microbial
One must be clever to study soil microbes and fungi. Their life
processes and ecological interactions can't be easily observed
directly in the soil with a microscope. Usually, scientists study
microorganisms by finding an artificial medium on which they grow
well and observe the activities of a large colony or pure culture--a
very restricted view. There probably are more species of
microorganisms than all other living things combined, yet we often
can't identify one species from another similar one by their
appearance. We can generally classify bacteria by shape: round ones,
rod-shaped ones, spiral ones, etc. We differentiate them by which
antibiotic kills them and by which variety of artificial material
they prefer to grow on. Pathogens are recognized by their prey.
Still, most microbial activities remain a great mystery.
Krasilnikov's great contribution to science was discovering how soil
microorganisms assist the growth of higher plants. Bacteria are very
fussy about the substrate they'll grow on. In the laboratory, one
species grows on protein gel, another on seaweed. One thrives on
beet pulp while another only grows on a certain cereal extract.
Plants "understand" this and manipulate their soil environment to
enhance the reproduction of certain bacteria they find desirable
while suppressing others. This is accomplished by root exudates.
For every 100 grams of above-ground biomass, a plant will excrete
about 25 grams of root exudates, creating a chemically different
zone (rhizosphere) close to the root that functions much like the
culture medium in a laboratory. Certain bacteria find this region
highly favorable and multiply prolifically, others are suppressed.
Bacterial counts adjacent to roots will be in hundreds of millions
to billions per gram of soil. A fraction of an inch away beyond the
influence of the exudates, the count drops greatly.
Why do plants expend energy culturing bacteria? Because there is an
exchange, a _quid pro quo._ These same bacteria assist the plant in
numerous ways. Certain types of microbes are predators. Instead of
consuming dead organic matter they attack living plants. However,
other species, especially actinomycetes, give off antibiotics that
suppress pathogens. The multiplication of actinomycetes can be
enhanced by root exudates.
Perhaps the most important benefit plants receive from soil bacteria
are what Krasilnikov dubbed "phytamins," a word play on vitamins
plus _phyta_ or "plant" in Greek. Helpful bacteria exude complex
water-soluble organic molecules that plants uptake through their
roots and use much like humans need certain vitamins. When plants
are deprived of phytamins they are less than optimally healthy, have
lowered disease resistance, and may not grow as large because some
phytamins act as growth hormones.
Keep in mind that beneficial microorganisms clustering around plant
roots do not primarily eat root exudates; exudates merely optimize
environmental conditions to encourage certain species. The main food
of these soil organisms is decaying organic matter and humus.
Deficiencies in organic matter or soil pH outside a comfortable
range of 5.75-7.5 greatly inhibit beneficial microorganisms.
For a long time it has been standard "chemical" ag science to deride
the notion that plant roots can absorb anything larger than simple,
inorganic molecules in water solution. This insupportable view is no
longer politically correct even among adherents of chemical usage.
However, if you should ever encounter an "expert" still trying to
intimidate others with these old arguments merely ask them, since
plant roots cannot assimilate large organic molecules, why do people
succeed using systemic chemical pesticides? Systemics are large,
complex poisonous organic molecules that plants uptake through their
roots and that then make the above-ground plant material toxic to
predators. Ornamentals, like roses, are frequently protected by
systemic chemical pesticides mixed into chemical fertilizer and fed
through the soil.
Root exudates have numerous functions beyond affecting
microorganisms. One is to suppress or encourage the growth of
surrounding plants Gardeners experience this as plant companions and
antagonists. Walnut tree root exudates are very antagonistic to many
other species. And members of the onion family prevent beans from
growing well if their root systems are intermixed.
Many crop rotational schemes exist because the effects of root
exudates seem to persist for one or even two years after the
original plant grew That's why onions grow very well when they are
planted where potatoes grew the year before. And why farmers grow a
three year rotation of hay, potatoes and onions. That is also why
onions don't grow nearly as well following cabbage or squash.
Farmers have a much easier time managing successions. They can grow
40 acres of one crop followed by 40 acres of another. But squash
from 100 square feet may overwhelm the kitchen while carrots from
the same 100 square feet the next year may not be enough. Unless you
keep detailed records, it is hard to remember exactly where
everything grew as long as two years ago in a vegetable garden and
to correlate that data with this year's results. But when I see half
a planting on a raised bed grow well and the adjacent half grow
poorly, I assume the difficulty was caused by exudate remains from
whatever grew there one, or even, two years ago.
In 1990, half of crop "F" grew well, half poorly. this was due to
the presence of crop "D" in 1989. The gardener might remember that
"D" was there last year. But in 1991, half of crop "G" grew well,
half poorly. This was also due to the presence of crop "D" two years
ago. Few can make this association.
These effects were one reason that Sir Albert Howard thought it was
very foolish to grow a vegetable garden in one spot for too many
years. He recommended growing "healing grass" for about five years
following several years of vegetable gardening to erase all the
exudate effects and restore the soil ecology to normal.
Mycorrhizal association is another beneficial relationship that
should exist between soil organisms and many higher plants. This
symbiotic relationship involves fungi and plant roots. Fungi can be
pathogenic, consuming living plants. But most of them are harmless
and eat only dead, decaying organic matter. Most fungi are soil
dwellers though some eat downed or even standing trees.
Most people do not realize that plant roots adsorb water and
water-soluble nutrients only through the tiny hairs and actively
growing tips near the very end of the root. The ability for any new
root to absorb nutrition only lasts a short time, then the hairs
slough off and the root develops a sort of hard bark. If root system
growth slows or stops, the plant's ability to obtain nourishment is
greatly reduced. Roots cannot make oxygen out of carbon dioxide as
do the leaves. That's why it is so important to maintain a good
supply of soil air and for the soil to remain loose enough to allow
rapid root expansion.
When roots are cramped, top growth slows or ceases, health and
disease resistance drops, and plants may become stressed despite
applications of nutrients or watering. Other plants that do not seem
to be competing for light above ground may have ramified (filled
with roots) far wider expanses soil than a person might think. Once
soil is saturated with the roots and the exudates from one plant,
the same space may be closed off to the roots of another. Gardeners
who use close plantings and intensive raised beds often unknowingly
bump up against this limiting factor and are disappointed at the
small size of their vegetables despite heavy fertilization, despite
loosening the earth two feet deep with double digging, and despite
regular watering. Thought about in this way, it should be obvious
why double digging improves growth on crowded beds by increasing the
depth to which plants can root.
The roots of plants have no way to aggressively breakdown rock
particles or organic matter, nor to sort out one nutrient from
another. They uptake everything that is in solution, no more, no
less while replacing water evaporated from their leaves. However,
soil fungi are able to aggressively attack organic matter and even
mineral rock particles and extract the nutrition they want. Fungi
live in soil as long, complexly interconnected hair-like threads
usually only one cell thick. The threads are called "hyphae." Food
circulates throughout the hyphae much like blood in a human body.
Sometimes, individual fungi can grow to enormous sizes; there are
mushroom circles hundreds of feet in diameter that essentially are
one single very old organism. The mushrooms we think of when we
think "fungus" are actually not the organism, but the transitory
fruit of a large, below ground network.
Certain types of fungi are able to form a symbiosis with specific
plant species. They insert a hyphae into the gap between individual
plant cells in a root hair or just behind the growing root tip. Then
the hyphae "drinks" from the vascular system of the plant, robbing
it of a bit of its life's blood. However, this is not harmful
predation because as the root grows, a bark develops around the
hyphae. The bark pinches off the hyphae and it rapidly decays inside
the plant, making a contribution of nutrients that the plant
couldn't otherwise obtain. Hyphae breakdown products may be in the
form of complex organic molecules that function as phytamins for the
Not all plants are capable of forming mycorrhizal associations.
Members of the cabbage family, for example, do not. However, if the
species can benefit from such an association and does not have one,
then despite fertilization the plant will not be as healthy as it
could be, nor grow as well. This phenomenon is commonly seen in
conifer tree nurseries where seedling beds are first completely
sterilized with harsh chemicals and then tree seeds sown. Although
thoroughly fertilized, the tiny trees grow slowly for a year or so.
Then, as spores of mycorrhizal fungi begin falling on the bed and
their hyphae become established, scattered trees begin to develop
the necessary symbiosis and their growth takes off. On a bed of
two-year-old seedlings, many individual trees are head and shoulders
above the others. This is not due to superior genetics or erratic
soil fertility. These are the individuals with a mycorrhizal
Like other beneficial microorganisms, micorrhizal fungi do not
primarily eat plant vascular fluid, their food is decaying organic
matter. Here's yet another reason to contend that soil productivity
can be measured by humus content.
Maintaining Soil Humus
Organic matter benefits soil productivity not because it is present,
but because all forms of organic matter in the soil, including its
most stable form--humus--are disappearing. Mycorrhizal fungi and
beneficial bacterial colonies around plant roots can exist only by
consuming soil organic matter. The slimes and gums that cement soil
particles into relatively stable aggregates are formed by
microorganisms as they consume soil organic matter. Scats and casts
that _are_ soil crumbs form only because organic matter is being
consumed. If humus declines, the entire soil ecology runs down and
with it, soil tilth and the health and productivity of plants.
If you want to manage your garden soil wisely, keep foremost in mind
that the rate of humus loss is far more important than the amount of
humus present. However, natural processes remove humus without our
aid or attention while the gardener's task is to add organic matter.
So there is a very understandable tendency to focus on addition, not
subtraction. But, can we add too much? And if so, what happens when
How Much Humus is Soil Supposed to Have?
If you measured the organic matter contents of various soils around
the United States there would be wide differences. Some variations
on crop land are due to great losses that have been caused by
mismanagement. But even if you could measure virgin soils never used
by humans there still would be great differences. Hans Jenny, a soil
scientist at the University of Missouri during the 1940s, noticed
patterns in soil humus levels and explained how and why this occurs
in a wonderfully readable book, _Factors in Soil Formation._ These
days, academic agricultural scientists conceal the basic simplicity
of their knowledge by unnecessarily expressing their data with
exotic verbiage and higher mathematics. In Jenny's time it was not
considered demeaning if an intelligent layman could read and
understand the writings of a scientist or scholar. Any serious
gardener who wants to understand the wide differences in soil should
become familiar with _Factors in Soil Formation._ About organic
matter in virgin soils, Jenny said:
"Within regions of similar moisture conditions, the organic matter
content of soil . . . decreases from north to south. For each fall
of 10 degree C (18 degree F) in annual temperature the average
organic matter content of soil increases two or three times,
provided that [soil moisture] is kept constant."
Moist soil during the growing season encourages plant growth and
thus organic matter production. Where the soil becomes dry during
the growing season, plant growth slows or stops. So, all things
being equal, wet soils contain more organic matter than dry ones.
All organic matter eventually rots, even in soil too dry to grow
plants. The higher the soil temperature the faster the
decomposition. But chilly (not frozen) soils can still grow a lot of
biomass. So, all things being equal, hot soils have less humus in
them than cold ones. Cool, wet soils will have the highest levels;
hot, dry soils will be lowest in humus.
This model checks out in practice. If we were to measure organic
matter in soils along the Mississippi River where soil moisture
conditions remain pretty similar from south to north, we might find
2 percent in sultry Arkansas, 3 percent in Missouri and over 4
percent in Wisconsin, where soil temperatures are much lower. In
Arizona, unirrigated desert soils have virtually no organic matter.
In central and southern California where skimpy and undependable
winter rains peter out by March, it is hard to find an unirrigated
soil containing as much as 1 percent organic matter while in the
cool Maritime northwest, reliable winter rains keep the soil damp
into June and the more fertile farm pastures or natural prairies may
develop as much as 5 percent organic matter.
Other factors, like the basic mineral content of the soil or its
texture, also influence the amount of organic matter a spot will
create and will somewhat increase or decrease the humus content
compared to neighboring locations experiencing the same climate. But
the most powerfully controlling influences are moisture and
On all virgin soils the organic matter content naturally sustains
itself at the highest possible level. And, average annual additions
exactly match the average annual amount of decomposition. Think
about that for a moment. Imagine that we start out with a plot of
finely-ground rock particles containing no life and no organic
matter. As the rock dust is colonized by life forms that gradually
build in numbers it becomes soil. The organic matter created there
increases nutrient availability and accelerates the breakdown of
rock particles, further increasing the creation of organic matter.
Soil humus steadily increases. Eventually a climax is sustained
where there is as much humus in the soil as there can be.
The peak plant and soil ecology that naturally lives on any site is
usually very healthy and is inevitably just as abundant as there is
moisture and soil minerals to support it. To me this suggests how
much organic matter it takes to grow a great vegetable garden. My
theory is that in terms of soil organic matter, vegetables grow
quite well at the humus level that would peak naturally on a virgin
site. In semi-arid areas I'd modify the theory to include an
increase as a result of necessary irrigation. Expressed as a rough
rule of thumb, a mere 2 percent organic matter in hot climates
increasing to 5 percent in cool ones will supply sufficient
biological soil activities to grow healthy vegetables if _the
mineral nutrient levels are high enough too._
Recall my assertion that what is most important about organic matter
is not how much is present, but how much is lost each year through
decomposition. For only by decomposing does organic matter release
the nutrients it contains so plants can uptake them; only by being
consumed does humus support the microecology that so markedly
contributes phytamins to plant nutrition, aggressively breaks down
rock particles and releases the plant nutrients they contain; only
by being eaten does soil organic matter support bacteria and
earthworms that improve productivity and create better tilth.
Here's something I find very interesting. Temperate climates having
seasons and winter, vary greatly in average temperature. Comparing
annual decomposition loss from a hot soil carrying 2 percent humus
with annual decomposition loss from a cooler soil carrying 5
percent, roughly the same amount of organic matter will decay out of
each soil during the growing season. _This means that in temperate
regions we have to replace about the same amount of organic matter
no matter what the location._
Like other substantial colleges of agriculture, the University of
Missouri ran some very valuable long-term studies in soil
management. In 1888, a never-farmed field of native prairie grasses
was converted into test plots. For fifty succeeding years each plot
was managed in a different but consistent manner. The series of
experiments that I find the most helpful recorded what happens to
soil organic matter as a consequence of farming practices. The
virgin prairie had sustained an organic matter content of about 3.5
percent. The lines on the graph show what happened to that organic
matter over time.
Timothy grass is probably a slightly more efficient converter of
solar energy into organic matter than was the original prairie.
After fifty years of feeding the hay cut from the field and
returning all of the livestock's manure, the organic matter in the
soil increased about 1/2 percent. Obviously, green manuring has very
limited ability to increase soil humus above climax levels. Growing
oats and returning enough manure to represent the straw and grain
fed to livestock, the field held its organic matter relatively
Growing small grain and removing everything but the stubble for
fifty years greatly reduced the organic matter. Keep in mind that
half the biomass production in a field happens below ground as
roots. And keep in mind that the charts don't reveal the sad
appearance the crops probably had once the organic matter declined
significantly. Nor do they show that the seed produced on those
degenerated fields probably would no longer sprout well enough to be
used as seedgrain, so new seed would have been imported into the
system each season, bringing with it new supplies of plant
nutrients. Without importing that bushel or so of wheat seed on each
acre each year, the curves would have been steeper and gone even
Corn is the hardest of the cereals on soil humus. The reason is,
wheat is closely broadcast in fall and makes a thick grassy
overwintering stand that forms biomass out of most of the solar
energy striking the field from spring until early summer when the
seed forms. Leafy oats create a little more biomass than wheat.
Corn, on the other hand, is frost tender and can't be planted early.
It is also not closely planted but is sown in widely-spaced rows.
Corn takes quite a while before it forms a leaf canopy that uses all
available solar energy. In farming lingo, corn is a "row crop."
Vegetables are also row crops. Many types don't form dense canopies
that soak up all solar energy for the entire growing season like a
virgin prairie. As with corn, the ground is tilled bare, so for much
of the best part of the growing season little or no organic matter
is produced. Of all the crops that a person can grow, vegetables are
the hardest on soil organic matter. There is no way that vegetables
can maintain soil humus, even if all their residues are religiously
composted and returned. Soil organic matter would decline markedly
even in an experiment in which we raised some small animals
exclusively on the vegetables and returned all of their manure and
When growing vegetables we have to restore organic matter beyond the
amount the garden itself produces. The curves showing humus decline
at the University of Missouri give us a good hint as to how much
organic matter we are going to lose from vegetable gardening. Let's
make the most pessimistic possible estimate and suppose that
vegetable gardening is twice as hard on soil as was growing corn and
removing everything but the stubble and root systems.
With corn, about 40 percent of the entire organic matter reserve is
depleted in the first ten years. Let's suppose that vegetables might
remove almost _all_ soil humus in ten years, or 10 percent each year
for the first few years. This number is a crude. and for most places
in America, a wildly pessimistic guess.
However, 10 percent loss per year may understate losses in some
places. I have seen old row crop soils in California's central
valley that look like white-colored blowing dust. Nor does a 10
percent per year estimate quite allow for the surprising durability
I observe in the still black and rich-looking old vegetable seed
fields of western Washington State's Skaget Valley. These
cool-climate fields have suffered chemical farming for decades
without having been completely destroyed--yet.
How much loss is 10 percent per year? Let's take my own garden for
example. It started out as an old hay pasture that hadn't seen a
plow for twenty-five or more years and where, for the five years
I've owned the property, the annual grass production is not cut,
baled, and sold but is cut and allowed to lie in place. Each year's
accumulation of minerals and humus contributes to the better growth
of the next year's grass. Initially, my grass had grown a little
higher and a little thicker each year. But the steady increase in
biomass production seems to have tapered off in the last couple of
years. I suppose by now the soil's organic matter content probably
has been restored and is about 5 percent.
I allocate about one acre of that old pasture to garden land. In any
given year my shifting gardens occupy one-third of that acre. The
other two-thirds are being regenerated in healing grass. I measure
my garden in fractions of acres. Most city folks have little concept
of an acre; its about 40,000 square feet, or a plot 200' x 200'.
Give or take some, the plow pan of an acre weighs about two million
pounds. The plow pan is that seven inches of topsoil that is flipped
over by a moldboard plow, the seven inches where most biological
activity occurs, where virtually all of the soil's organic matter
resides. Two million pounds equals one thousand tons of topsoil in
the first seven inches of an acre. Five percent of that one thousand
tons can be organic matter, up to fifty priceless tons of life that
changes 950 tons of dead dust into a fertile, productive acre. If 10
percent of that fifty tons is lost as a consequence of one year's
vegetable gardening, that amounts to five tons per acre per year
lost or about 25 pounds lost per 100 square feet.
Patience, reader. There is a very blunt and soon to be a very
obvious point to all of this arithmetic. Visualize this! Lime is
spread at rates up to four tons per acre. Have you ever spread 1 T/A
or 50 pounds of lime over a garden 33 x 33 feet? Mighty hard to
accomplish! Even 200 pounds of lime would barely whiten the ground
of a 1,000 square-foot garden. It is even harder to spread a mere 5
tons of compost over an acre or only 25 pounds on a 100-square-foot
bed. It seems as though nothing has been accomplished, most of the
soil still shows, there is no _layer _of compost, only a thin
But for the purpose of maintaining humus content of vegetable ground
at a healthy level, a thin scattering once a year is a gracious
plenty. Even if I were starting with a totally depleted, dusty,
absolutely humusless, ruined old farm field that had no organic
matter whatsoever and I wanted to convert it to a healthy vegetable
garden, I would only have to make a one-time amendment of 50 tons of
ripe compost per acre or 2,500 pounds per 1,000 square feet. Now
2,500 pounds of humus is a groaning, spring-sagging, long-bed pickup
load of compost heaped up above the cab and dripping off the sides.
Spread on a small garden, that's enough to feel a sense of
accomplishment about. Before I knew better I used to incorporate
that much composted horse manure once or twice a year and when I did
add a half-inch thick layer that's about what I was applying.
Fertilizing Vegetables with Compost
Will a five ton per acre addition of compost provide enough
nutrition to grow great vegetables? Unfortunately, the answer
usually is no. In most gardens, in most climates, with most of what
passes for "compost," it probably won't. That much compost might
well grow decent wheat.
The factors involved in making this statement are numerous and too
complex to fully analyze in a little book like this one. They
include the intrinsic mineralization of the soil itself, the
temperature of the soil during the growing season, and the high
nutritional needs of the vegetables themselves. In my experience, a
few alluvial soils that get regular, small additions of organic
matter can grow good vegetable crops without additional help.
However, these sites are regularly flooded and replenished with
highly mineralized rock particles. Additionally, they must become
very warm during the growing season. But not all rock particles
contain high levels of plant nutrients and not all soils get hot
enough to rapidly break down soil particles.
Soil temperature has a great deal to do with how effectively compost
can act as fertilizer. Sandy soils warm up much faster in spring and
sand allows for a much freer movement of air, so humus decomposes
much more rapidly in sand. Perhaps a sunny, sandy garden on a
south-facing slope might grow pretty well with small amounts of
strong compost. As a practical matter, if most people spread even
the most potent compost over their gardens at only twenty-five
pounds per 100 square feet, they would almost certainly be
Well then, if five tons of quality compost to the acre isn't
adequate for most vegetables, what about using ten or twenty tons of
the best. Will that grow a good garden? Again, the answer must allow
for a lot of factors but is generally more positive. If the compost
has a low C/N and that compost, or the soil itself, isn't grossly
deficient in some essential nutrient, and if the soil has a coarse,
airy texture that promotes decomposition, then somewhat heavier
applications will grow a good-looking garden that yields a lot of
However, one question that is rarely asked and even more rarely
answered satisfactorily in the holistic farming and gardening lore
is: Precisely how much organic matter or humus is needed to maximize
plant health and the nutritional qualities of the food we're
growing? An almost equally important corollary of this is: Can there
be too much organic matter?
This second question is not of practical consequence for biological
grain/livestock farmers because it is almost financially impossible
to raise organic matter levels on farm soils to extraordinary
amounts. Large-scale holistic farmers must grow their own humus on
their own farm. Their focus cannot be on buying and bringing in
large quantities of organic matter; it must be on conserving and
maximizing the value of the organic matter they produce themselves.
Where you do hear of an organic farmer (not vegetable grower but
cereal/livestock farmer) building extraordinary fertility by
spreading large quantities of compost, remember that this farmer
must be located near an inexpensive source of quality material. If
all the farmers wanted to do the same there would not be enough to
go around at an economic price unless, perhaps, the entire country
became a "closed system" like China. We would have to compost every
bit of human excrement and organic matter and there still wouldn't
be enough to meet the demand. Even if we became as efficient as
China, keep in mind the degraded state of China's upland soils and
the rapid desertification going on in their semi-arid west. China is
robbing Peter to pay Paul and may not have a truly sustainable
I've frequently encountered a view among devotees of the organic
gardening movement that if a little organic matter is a good thing,
then more must be better and even more better still. In Organic
Gardening magazine and Rodale garden books we read eulogies to soils
that are so high in humus and so laced with earthworms that one can
easily shove their arm into the soft earth elbow deep but must yank
it out fast before all the hairs have been chewed off by worms,
where one must jump away after planting corn seeds lest the stalk
poke you in the eye, where the pumpkins average over 100 pounds
each, where a single trellised tomato vine covers the entire south
side of a house and yields bushels. All due to compost.
I call believers of the organic faith capital "O" organic gardeners.
These folks almost inevitably have a pickup truck used to gather in
their neighborhood's leaves and grass clippings on trash day and to
haul home loads from local stables and chicken ranches. Their large
yards are ringed with compost bins and their annual spreadings of
compost are measured in multiples of inches. I was one once, myself.
There are two vital and slightly disrespectful questions that should
be asked about this extreme of gardening practice. Is this much
humus the only way to grow big, high-yielding organic vegetable
gardens and two, are vegetables raised on soils super-high in humus
maximally nutritious. If the answer to the first question is no,
then a person might avoid a lot of work by raising the nutrient
level of their soil in some other manner acceptable to the organic
gardener. If the answer to the second question is less nutritious,
then serious gardeners and homesteaders who are making home-grown
produce into a significant portion of their annual caloric intake
had better reconsider their health assumptions. A lot of organic
gardeners cherish ideas similar to the character Woody Allen played
in his movie, Sleeper.
Do you recall that movie? It is about a contemporary American who,
coming unexpectedly close to death, is frozen and then reanimated
and healed 200 years in the future. However, our hero did not expect
to die or be frozen when he became ill and upon awakening believes
the explanation given to him is a put on and that his friends are
conspiring to make him into a fool. The irritated doctor in charge
tells Woody to snap out of it and be prepared to start a new life.
This is no joke, says the doctor, all of Woody's friends are long
since dead. Woody's response is a classic line that earns me a few
chuckles from the audience every time I lecture: 'all my friends
can't be dead! I owned a health food store and we all ate brown
Humus and the Nutritional Quality of Food
I believe that the purpose of food is not merely to fill the belly
or to provide energy, but to create and maintain health. Ultimately,
soil fertility should be evaluated not by humus content, nor
microbial populations, nor earthworm numbers, but by the long-term
health consequences of eating the food. If physical health
degenerates, is maintained, or is improved we have measured the
soil's true worth. The technical name for this idea is a "biological
assay." Evaluating soil fertility by biological assay is a very
radical step, for connecting long-term changes in health with the
nutritional content of food and then with soil management practices
invalidates a central tenet of industrial farming: that bulk yield
is the ultimate measure of success or failure. As Newman Turner, an
English dairy farmer and disciple of Sir Albert Howard, put it:
"The orthodox scientist normally measures the fertility of a soil by
its bulk yield, with no relation to effect on the ultimate consumer.
I have seen cattle slowly lose condition and fall in milk yield when
fed entirely on the abundant produce of an apparently fertile soil.
Though the soil was capable of yielding heavy crops, those crops
were not adequate in themselves to maintain body weight and milk
production in the cow, without supplements. That soil, though
capable of above-average yields, and by the orthodox quantitative
measure regarded as fertile, could not, by the more complete measure
of ultimate effect on the consumer, be regarded but anything but
deficient in fertility.
Fertility therefore, is the ability to produce at the highest
recognized level of yield, crops of quality which, when consumed
over long periods by animals or man, enable them to sustain health,
bodily condition and high level of production without evidence of
disease or deficiency of any kind.
Fertility cannot be measured quantitatively. Any measure of soil
fertility must be related to the quality of its produce. . . . the
most simple measure of soil fertility is its ability to transmit,
through its produce, fertility to the ultimate consumer."
Howard also tells of creating a super-healthy herd of work oxen on
his research farm at Indore, India. After a few years of meticulous
composting and restoration of soil life, Howard's oxen glowed with
well-being. As a demonstration he intentionally allowed his animals
to rub noses across the fence with neighboring oxen known to be
infected with hoof and mouth and other cattle plagues. His animals
remained healthy. I have read so many similar accounts in the
literature of the organic farming movement that in my mind there is
no denying the relationship between the nutritional quality of
plants and the presence of organic matter in soil. Many other
organic gardeners reach the same conclusion. But most gardeners do
not understand one critical difference between farming and
gardening: most agricultural radicals start farming on run-down land
grossly deficient in organic matter. The plant and animal health
improvements they describe come from restoration of soil balance,
from approaching a climax humus level much like I've done in my
pasture by no longer removing the grass.
But home gardeners and market gardeners near cities are able to get
their hands on virtually unlimited quantities of organic matter.
Encouraged by a mistaken belief that the more organic matter the
healthier, they enrich their soil far beyond any natural capacity.
Often this is called "building up the soil." But increasing organic
matter in gardens well above a climax ecology level does not further
increase the nutritional value of vegetables and in many
circumstances will decrease their value markedly.
For many years I have lectured on organic gardening to the Extension
Service's master gardener classes. Part of the master gardener
training includes interpreting soil test results. In the early 1980s
when Oregon State government had more money, all master gardener
trainees were given a free soil test of their own garden.
Inevitably, an older gentlemen would come up after my lecture and
ask my interpretation of his puzzling soil test.
Ladies, please excuse me. Lecturing in this era of women's lib I've
broken my politically incorrect habit of saying "the gardener, he ..."
but in this case it _was _always a man, an organic gardener who
had been building up his soil for years.
The average soils in our region test moderately-to strongly acid;
are low in nitrogen, phosphorus, calcium, and magnesium; quite
adequate in potassium; and have 3-4 percent organic matter. Mr.
Organic's soil test showed an organic matter content of 15 to 20
percent with more than adequate nitrogen and a pH of 7.2. However
there was virtually no phosphorus, calcium or magnesium and four
times the amount of potassium that any farm agent would ever
recommend. On the bottom of the test, always written in red ink,
underlined, with three exclamation points, "No more wood ashes for
five years!!!" Because so many people in the Maritime northwest heat
with firewood, the soil tester had mistakenly assumed that the soil
became alkaline and developed such a potassium imbalance from heavy
applications of wood ashes.
This puzzled gardener couldn't grasp two things about his soil test
report. One, he did not use wood ashes and had no wood stove and
two, although he had been "building up his soil for six or seven
years," the garden did not grow as well as he had imagined it would.
Perhaps you see why this questioner was always a man. Mr. Organic
owned a pickup and loved to haul organic matter and to make and
spread compost. His soil was full of worms and had a remarkably high
humus level but still did not grow great crops.
It was actually worse than he understood. Plants uptake as much
potassium as there is available in the soil, and concentrate that
potassium in their top growth. So when vegetation is hauled in and
composted or when animal manure is imported, large quantities of
potassium come along with them. As will be explained shortly,
vegetation from forested regions like western Oregon is even more
potassium-rich and contains less of other vital nutrients than
vegetation from other areas. By covering his soil several inches
thick with manure and compost every year he had totally saturated
the earth with potassium. Its cation exchange capacity or in
non-technical language, the soil's ability to hold other nutrients
had been overwhelmed with potassium and all phosphorus, calcium,
magnesium, and other nutrients had largely been washed away by rain.
It was even worse than that! The nutritional quality of the
vegetables grown on that superhumusy soil was very, very low and
would have been far higher had he used tiny amounts of compost and,
horror of all horrors, chemical fertilizer.
Climate and the Nutritional Quality of Food
Over geologic time spans, water passing through soil leaches or
removes plant nutrients. In climates where there is barely enough
rain to grow cereal crops, soils retain their minerals and the food
produced there tends to be highly nutritious. In verdant, rainy
climates the soil is leached of plant nutrients and the food grown
there is much less nutritious. That's why the great healthy herds of
animals were found on scrubby, semi-arid grasslands like the
American prairies; in comparison, lush forests carry far lower
quantities of animal biomass.
Some plant nutrients are much more easily leached out than others.
The first valuable mineral to go is calcium. Semi-arid soils usually
still retain large quantities of calcium. The nutrient most
resistant to leaching is potassium. Leached out forest soils usually
still retain relatively large amounts of potassium. William Albrecht
observed this data and connected with it a number of fairly obvious
and vital changes in plant nutritional qualities that are caused by
these differences in soil fertility. However obvious they may be,
Albrecht's work was not considered politically correct by his peers
or the interest groups that supported agricultural research during
the mid-twentieth century and his contributions have been largely
ignored. Worse, his ideas did not quite fit with the ideological
preconceptions of J.l. Rodale, so organic gardeners and farmers are
also ignorant of Albrecht's wisdom.
Albrecht would probably have approved of the following chart that
expresses the essential qualities of dryland and humid soils.
Soil Mineral Content by Climate Area
Plant Nutrient Dryland Prairie Soil Humid Forest Soil
nitrogen high low
phosphorus high low
potassium high moderately high
calcium very high low
pH neutral acid
Dryland soils contain far higher levels of all minerals than leached
soils. But Albrecht speculated that the key difference between these
soils is the _ratio _of calcium to potassium. In dryland soils there
is much more calcium in the soil than there is potassium while in
wetter soils there is as much or more potassium than calcium. To
test his theory he grew some soybeans in pots. One pot had soil with
a high amount of calcium relative to the amount of potassium,
imitating dryland prairie soil. The other pot had just as much
calcium but had more potassium, giving it a ratio similar to a high
quality farm soil in the eastern United States. Both soils grew
good-looking samples of soybean plants, but when they were analyzed
for nutritional content they proved to be quite different.
Soil Yield Calories Protein Calcium Phosphorus Potassium
Humid 17.8 gm High 13% 0.27% 0.14% 2.15%
Dryland 14.7 gm Medium 17% 0.74% 0.25% 1.01%
The potassium-fortified soil gave a 25 percent higher bulk yield but
the soybeans contained 25 percent less protein. The consumer of
those plants would have to burn off approximately 30 percent more
carbohydrates to obtain the same amount of vital amino acids
essential to all bodily functions. Wet-soil plants also contain only
one-third as much calcium, an essential nutrient, whose lack over
several generations causes gradual reduction of skeletal size and
dental deterioration. They also contain only half as much
phosphorus, another essential nutrient. Their oversupply of
potassium is not needed; humans eating balanced diets usually
excrete large quantities of unnecessary potassium in their urine.
Albrecht then analyzed dozens of samples of vegetation that came
from both dryland soils and humid soils and noticed differences in
them similar to the soybeans grown under controlled conditions. The
next chart, showing the average composition of plant vegetation from
the two different regions, is taken directly from Albrecht's
research. The figures are averages of large numbers of plant
samples, including many different food crops from each climate.
Average Nutritional Content by Climate
Nutrient Dryland Soil Humid Soil
Potassium 2.44% 1.27%
Calcium 1.92% 0.28%
Phosphorus 0.78% 0.42%
Total mineral nutrition 5.14% 1.97%
Ratio of Potassium to Calciuim 1.20/1 4.50/1
Analyzed as a whole, these data tell us a great deal about how we
should manage our soil to produce the most nutritious food and about
the judicious use of compost in the garden as well. I ask you to
refer back to these three small charts as I point out a number of
conclusions that can be drawn from them.
The basic nutritional problem that all animals have is not about
finding energy food, but how to intake enough vitamins, minerals and
usable proteins. What limits our ability to intake nutrients is the
amount of bulk we can process--or the number of calories in the
food. With cows, for example, bulk is the limiter. The cow will
completely fill her digestive tract at all times and will process
all the vegetation she can digest every day of her life. Her health
depends on the amount of nutrition in that bulk. With humans, our
modern lifestyle limits most of us to consuming 1,500 to 1,800
calories a day. Our health depends on the amount of nutrients coming
along with those calories.
So I write the fundamental equation for human health as follows:
HEALTH = NUTRITION IN FOOD DIVIDED BY CALORIES IN THAT FOOD
If the food that we eat contains all of the nutrients that food
could possibly contain, and in the right ratios, then we will get
sufficient nutrition while consuming the calories we need to supply
energy. However, to the degree that our diet contains denatured food
supplying too much energy, we will be lacking nutrition and our
bodies will suffer gradual degeneration. This is why foods such as
sugar and fat are less healthful because they are concentrated
sources of energy that contain little or no nutrition. Nutritionless
food also contributes to "hidden hungers" since the organism craves
something that is missing. The body overeats, and becomes fat and
Albrecht's charts show us that food from dry climates tends to be
high in proteins and essential minerals while simultaneously lower
in calories. Food from wet climates tends to be higher in calories
while much lower in protein and essential mineral nutrients.
Albrecht's writings, as well as those of Weston Price, and Sir
Robert McCarrison listed in the bibliography, are full of examples
showing how human health and longevity are directly associated with
these same variations in climate, soil, and food nutrition.
Albrecht pointed out a clear example of soil fertility causing
health or sickness. In 1940, when America was preparing for World
War II, all eligible men were called in for a physical examination
to determine fitness for military service. At that time, Americans
did not eat the same way we do now. Food was produced and
distributed locally. Bread was milled from local flour. Meat and
milk came from local farmers. Vegetables and potatoes did not all
come from California. Regional differences in soil fertility could
be seen reflected in the health of people.
Albrecht's state, Missouri, is divided into a number of distinct
rainfall regions. The northwestern part is grassy prairie and
receives much less moisture than the humid, forested southeastern
section. If soil tests were compared across a diagonal line drawn
from the northwest to the southeast, they would exactly mimic the
climate-caused mineral profile differences Albrecht had identified.
Not unexpectedly, 200 young men per 1,000 draftees were medically
unfit for military service from the northwest part of Missouri while
400 per 1,000 were unfit from the southeastern part. And 300 per
1,000 were unfit from the center of the state.
Another interesting, and rather frightening, conclusion can be drawn
from the second chart. Please notice that by increasing the amount
of potassium in the potting soil, Albrecht increased the overall
yield by 25 percent while simultaneously lowering all of the other
significant nutritional aspects. Most of this increase of yield was
in the form of carbohydrates, that in a food crops equates to
calories. Agronomists also know that adding potassium fertilizer
greatly and inexpensively increases yield. So American farm soils
are routinely dosed with potassium fertilizer, increasing bulk yield
and profits without consideration for nutrition, or for the ultimate
costs in public health. Organic farmers often do not understand this
aspect of plant nutrition either and may use "organic" forms of
potassium to increase their yields and profits. Buying organically
grown food is no guarantee that it contains the ultimate in
So, if health comes from paying attention to the ratio of nutrition
to calories in our food, then as gardeners who are in charge of
creating a significant amount of our own fodder, we can take that
equation a step further:
HEALTH = Nutrition/Calories = Calcium/Potassium
When we decide how to manage our gardens we can take steps to
imitate dryland soils by keeping potassium levels lower while
maintaining higher levels of calcium.
Now take another close look at the third chart. Average vegetation
from dryland soils contains slightly more potassium than calcium
(1.2:1) while average vegetation from wetland soils contains many
more times more potassium than calcium (4.5:1). When we import
manure or vegetation into our garden or farm soils we are adding
large quantities of potassium. Those of us living in rainy climates
that were naturally forested have it much worse in this respect than
those of us gardening on the prairies or growing irrigated gardens
in desert climates because the very vegetation and manure we use to
"build up" our gardens contains much more potassium while most of
our soils already contain all we need and then some.
It should be clear to you now why some organic gardeners receive the
soil tests like the man at my lecture. Even the soil tester,
although scientifically trained and university educated, did not
appreciate the actual source of the potassium overdose. The tester
concluded it must have been wood ashes when actually the potassium
came from organic matter itself.
I conclude that organic matter is somewhat dangerous stuff whose use
should be limited to the amount needed to maintain basic soil tilth
and a healthy, complex soil ecology.
Fertilizing Gardens Organically
Scientists analyzing the connections between soil fertility and the
nutritional value of crops have repeatedly remarked that the best
crops are grown with compost and fertilizer. Not fertilizer alone
and not compost alone. The best place for gardeners to see these
data is Werner Schupan's book (listed in the bibliography).
But say the word "fertilizer" to an organic gardener and you'll
usually raise their hackles. Actually there is no direct linkage of
the words "fertilizer" and "chemical." A fertilizer is any
concentrated plant nutrient source that rapidly becomes available in
the soil. In my opinion, chemicals are the poorest fertilizers;
organic fertilizers are far superior.
The very first fertilizer sold widely in the industrial world was
guano. It is the naturally sun-dried droppings of nesting sea birds
that accumulates in thick layers on rocky islands off the coast of
South America. Guano is a potent nutrient source similar to dried
chicken manure, containing large quantities of nitrogen, fair
amounts of phosphorus, and smaller quantities of potassium. Guano is
more potent than any other manure because sea birds eat ocean fish,
a very high protein and highly mineralized food. Other potent
organic fertilizers include seed meals; pure, dried chicken manure;
slaughterhouse wastes; dried kelp and other seaweeds; and fish meal.
Composition of Organic Fertilizers
Material % Nitrogen % Phos. % Potassium
Alfalfa meal 2.5 0.5 2.1
Bone meal (raw) 3.5 21.0 0.2
Bone meal (steamed) 2.0 21.0 0.2
Chicken manure (pure, fresh) 2.6 1.25 0.75
Cottonseed meal 7.0 3.0 2.0
Blood meal 12.0 3.0 --
Fish meal 8.0 7.0 --
Greensand -- 1.5 7.0
Hoof and Horn 12.5 2.0 --
Kelp meal 1.5 0.75 4.9
Peanut meal 3.6 0.7 0.5
Tankage 11.0 5.0 --
Growing most types of vegetables requires building a level of soil
fertility that is much higher than required by field crops like
cereals, soybeans, cotton and sunflowers. Field crops can be
acceptably productive on ordinary soils without fertilization.
However, because we have managed our farm soils as depreciating
industrial assets rather than as relatively immortal living bodies,
their ability to deliver plant nutrients has declined and the
average farmer usually must add additional nutrients in the form of
concentrated, rapidly-releasing fertilizers if they are going to
grow a profitable crop.
Vegetables are much more demanding than field crops. They have long
been adapted to growing on potent composts or strong manures like
fresh horse manure or chicken manure. Planted and nourished like
wheat, most would refuse to grow or if they did survive in a wheat
field, vegetables would not produce the succulent, tender parts we
Building higher than normal levels of plant nutrients can be done
with large additions of potent compost and manure. In semi-arid
parts of the country where vegetation holds a beneficial ratio of
calcium to potassium food grown that way will be quite nutritious.
In areas of heavier rainfall, increasing soil fertility to vegetable
levels is accomplished better with fertilizers. The data in the
previous section gives strong reasons for many gardeners to limit
the addition of organic matter in soil to a level that maintains a
healthy soil ecology and acceptable tilth. Instead of supplementing
compost with low quality chemical fertilizers, I recommend making
and using a complete organic fertilizer mix to increase mineral
Making and Using Complete Organic Fertilizer
The basic ingredients used for making balanced organic fertilizers
can vary and what you decide on will largely depend on where you
live. Seed meal usually forms the body of the blend. Seed meals are
high in nitrogen and moderately rich in phosphorus because plants
concentrate most of the phosphorus they collect during their entire
growth cycle into their seeds to serve to give the next generation a
strong start. Seed meals contain low but more than adequate amounts
The first mineral to be removed by leaching is calcium. Adding lime
can make all the difference in wet soils. Dolomite lime also adds
magnesium and is the preferable form of lime to use in a fertilizer
blend on most soils. Gypsum could be substituted for lime in arid
areas where the soils are naturally alkaline but still may benefit
from additional calcium. Kelp meal contains valuable trace minerals.
If I were short of money, first I'd eliminate the kelp meal, then
the phosphate source.
All ingredients going into this formula are measured by volume and
the measurements can be very rough: by sack, by scoop, or by coffee
can. You can keep the ingredients separated and mix fertilizer by
the bucketful as needed or you can dump the contents of half a dozen
assorted sacks out on a concrete sidewalk or driveway and blend them
with a shovel and then store the mixture in garbage cans or even in
the original sacks the ingredients came in.
This is my formula.
4 parts by volume: Any seed meal such as cottonseed meal, soybean
meal, sunflower meal, canola meal, linseed meal, safflower, peanut
meal or coconut meal. Gardeners with deep pocketbooks and
insensitive noses can also fish meal. Gardeners without vegetarian
scruples may use meat meal, tankage, leather dust, feather meal or
other slaughterhouse waste.
1 part by volume: Bone meal or rock phosphate
1 part by volume: Lime, preferably dolomite on most soils.
(Soils derived from serpentine rock contain almost toxic levels of
magnesium and should not receive dolomite. Alkaline soils may still
benefit from additional calcium and should get gypsum instead of
1/2 part by volume: kelp meal or other dried seaweed.
To use this fertilizer, broadcast and work in about one gallon per
each 100 square feet of growing bed or 50 feet of row. This is
enough for all low-demand vegetables like carrots, beans and peas.
For more needy species, blend an additional handful or two into
about a gallon of soil below the transplants or in the hill. If
planting in rows, cut a deep furrow, sprinkle in about one pint of
fertilizer per 10-15 row feet, cover the fertilizer with soil and
then cut another furrow to sow the seeds in about two inches away.
Locating concentrations of nutrition close to seeds or seedlings is
I have a thick file of letters thanking me for suggesting the use of
this fertilizer blend. If you've been "building up your soil" for
years, or if your vegetables never seem to grow as large or lustily
as you imagine they should, I strongly suggest you experiment with a
small batch of this mixture. Wouldn't you like heads of broccoli
that were 8-12 inches in diameter? Or zucchini plants that didn't
Making Superior Compost
The potency of composts can vary greatly. Most municipal solid waste
compost has a high carbon to nitrogen ratio and when tilled into
soil temporarily provokes the opposite of a good growth response
until soil animals and microorganisms consume most of the undigested
paper. But if low-grade compost is used as a surface mulch on
ornamentals, the results are usually quite satisfactory even if
If the aim of your own composting is to conveniently dispose of yard
waste and kitchen garbage, the information in the first half of the
book is all you need to know. If you need compost to make something
that dependably GROWS plants like it was fertilizer, then this
chapter is for you.
A Little History
Before the twentieth century, the fertilizers market gardeners used
were potent manures and composts. The vegetable gardens of country
folk also received the best manures and composts available while the
field crops got the rest. So I've learned a great deal from old
farming and market gardening literature about using animal manures.
In previous centuries, farmers classified manures by type and
purity. There was "long" and "short" manure, and then, there was the
supreme plant growth stimulant, chicken manure.
Chicken manure was always highly prized but usually in short supply
because preindustrial fowl weren't caged in factories or permanently
locked in hen houses and fed scientifically formulated mixes. The
chicken breed of that era was usually some type of bantam,
half-wild, broody, protective of chicks, and capable of foraging. A
typical pre-1900 small-scale chicken management system was to allow
the flock free access to hunt their own meals in the barnyard and
orchard, luring them into the coop at dusk with a bit of grain where
they were protected from predators while sleeping helplessly. Some
manure was collected from the hen house but most of it was dropped
where it could not be gathered. The daily egg hunt was worth it
because, before the era of pesticides, having chickens range through
the orchard greatly reduced problems with insects in fruit.
The high potency of chicken manure derives from the chickens' low
C/N diet: worms, insects, tender shoots of new grass, and other
proteinaceous young greens and seeds. Twentieth-century chickens
"living" in egg and meat factories must still be fed low C/N foods,
primarily grains, and their manure is still potent. But anyone who
has savored real free-range eggs with deep orange yokes from
chickens on a proper diet cannot be happy with what passes for
"eggs" these days.
Fertilizing with pure chicken manure is not very different than
using ground cereal grains or seed meals. It is so concentrated that
it might burn plant leaves like chemical fertilizer does and must be
applied sparingly to soil. It provokes a marked and vigorous growth
response. Two or three gallons of dry, pure fresh chicken manure are
sufficient nutrition to GROW about 100 square feet of vegetables in
raised beds to the maximum.
Exclusively incorporating pure chicken manure into a vegetable
garden also results in rapid humus loss, just as though chemical
fertilizers were used. Any fertilizing substance with a C/N below
that of stabilized humus, be it a chemical or a natural substance,
accelerates the decline in soil organic matter. That is because
nitrate nitrogen, the key to constructing all protein, is usually
the main factor limiting the population of soil microorganisms. When
the nitrate level of soil is significantly increased, microbe
populations increase proportionately and proceeds to eat organic
matter at an accelerated rate.
That is why small amounts of chemical fertilizer applied to soil
that still contains a reasonable amount of humus has such a powerful
effect. Not only does the fertilizer itself stimulate the growth of
plants, but fertilizer increases the microbial population. More
microbes accelerate the breakdown of humus and even more plant
nutrients are released as organic matter decays. And that is why
holistic farmers and gardeners mistakenly criticize chemical
fertilizers as being directly destructive of soil microbes.
Actually, all fertilizers, chemical or organic, _indirectly_ harm
soil life, first increasing their populations to unsustainable
levels that drop off markedly once enough organic matter has been
eaten. Unless, of course, the organic matter is replaced.
Chicken manure compost is another matter. Mix the pure manure with
straw, sawdust, or other bedding, compost it and, depending on the
amount and quantity of bedding used and the time allowed for
decomposition to occur, the resultant C/N will be around 12:1 or
above. Any ripened compost around 12:1 still will GROW plants
beautifully. Performance drops off as the C/N increases.
Since chicken manure was scarce, most pre-twentieth century market
gardeners depended on seemingly unlimited supplies of "short
manure," generally from horses. The difference between the "long"
and the "short" manure was bedding. Long manure contained straw from
the stall while short manure was pure street sweepings without
adulterants. Hopefully, the straw portion of long manure had
absorbed a quantity of urine.
People of that era knew the fine points of hay quality as well as
people today know their gasoline. Horses expected to do a day's work
were fed on grass or grass/clover mixes that had been cut and dried
while they still had a high protein content. Leafy hay was highly
prized while hay that upon close inspection revealed lots of stems
and seed heads would be rejected by a smart buyer. The working
horse's diet was supplemented with a daily ration of grain.
Consequently, uncomposted fresh short manure probably started out
with a C/N around 15:1. However, don't count on anything that good
from horses these days. Most horses aren't worked daily so their
fodder is often poor. Judging from the stemmy, cut-too-late grass
hay our local horses have to try to survive on, if I could find
bedding-free horse manure it would probably have a C/N more like
20:1. Manure from physically fit thoroughbred race horses is
Using fresh horse manure in soil gave many vegetables a harsh flavor
so it was first composted by mixing in some soil (a good idea
because otherwise a great deal of ammonia would escape the heap).
Market gardeners raising highly demanding crops like cauliflower and
celery amended composted short manure by the inches-thick layer.
Lesser nutrient-demanding crops like snap beans, lettuce, and roots
followed these intensively fertilized vegetables without further
Long manures containing lots of straw were considered useful only
for field crops or root vegetables. Wise farmers conserved the
nitrogen and promptly composted long manures. After heating and
turning the resulting C/N would probably be in a little below 20:1.
After tilling it in, a short period of time was allowed while the
soil digested this compost before sowing seeds. Lazy farmers spread
raw manure load by load as it came from the barn and tilled it in
once the entire field was covered. This easy method allows much
nitrogen to escape as ammonia while the manure dries in the sun.
Commercial vegetable growers had little use for long manure.
One point of this brief history lesson is GIGO: garbage in, garbage
out. The finished compost tends to have a C/N that is related to the
ingredients that built the heap. Growers of vegetables will wisely
Anyone interested in learning more about preindustrial market
gardening might ask their librarian to seek out a book called
_French Gardening_ by Thomas Smith, published in London about 1905.
This fascinating little book was written to encourage British market
gardeners to imitate the Parisian marcier, who skillfully
earned top returns growing out-of-season produce on intensive,
double-dug raised beds, often under glass hot or cold frames. Our
trendy American Biodynamic French Intensive gurus obtained their
inspiration from England through this tradition.
Curing the Heap
The easiest and most sure-fire improver of compost quality is time.
Making a heap with predominantly low C/N materials inevitably
results in potent compost if nitrate loss is kept to a minimum. But
the C/N of almost any compost heap, even one starting with a high
C/N will eventually lower itself. The key word here is _eventually._
The most dramatic decomposition occurs during the first few turns
when the heap is hot. Many people, including writers of garden
books, mistakenly think that the composting ends when the pile cools
and the material no longer resembles what made up the heap. This is
not true. As long as a compost heap is kept moist and is turned
occasionally, it will continue to decompose. "Curing" or "ripening"
are terms used to describe what occurs once heating is over.
A different ecology of microorganisms predominates while a heap is
ripening. If the heap contains 5 to 10 percent soil, is kept moist,
is turned occasionally so it stays aerobic, and has a complete
mineral balance, considerable bacterial nitrogen fixation may occur.
Most gardeners are familiar with the microbes that nodulate the
roots of legumes. Called rhizobia, these bacteria are capable of
fixing large quantities of nitrate nitrogen in a short amount of
time. Rhizobia tend to be inactive during hot weather because the
soil itself is supplying nitrates from the breakdown of organic
matter. Summer legume crops, like cowpeas and snap beans, tend to be
net consumers of nitrates, not makers of more nitrates than they can
use. Consider this when you read in carelessly researched garden
books and articles about the advantages of interplanting legumes
with other crops because they supposedly generate nitrates that
"help" their companions.
But during spring or fall when lowered soil temperatures retard
decomposition, rhizobia can manufacture from 80 to 200 pounds of
nitrates per acre. Peas, clovers, alfalfa, vetches, and fava beans
can all make significant contributions of nitrate nitrogen and smart
farmers prefer to grow their nitrogen by green manuring legumes.
Wise farmers also know that this nitrate, though produced in root
nodules, is used by legumes to grow leaf and stem. So the entire
legume must be tilled in if any net nitrogen gain is to be realized.
This wise practice simultaneously increases organic matter.
Rhizobia are not capable of being active in compost piles, but
another class of microbes is. Called azobacteria, these free-living
soil dwellers also make nitrate nitrogen. Their contribution is not
potentially as great as rhizobia, but no special provision must be
made to encourage azobacteria other than maintaining a decent level
of humus for them to eat, a balanced mineral supply that includes
adequate calcium, and a soil pH between 5.75 and 7.25. A
high-yielding crop of wheat needs 60-80 pounds of nitrates per acre.
Corn and most vegetables can use twice that amount. Azobacteria can
make enough for wheat, though an average nitrate contribution under
good soil conditions might be more like 30-50 pounds per year.
Once a compost heap has cooled, azobacteria will proliferate and
begin to manufacture significant amounts of nitrates, steadily
lowering the C/N. And carbon never stops being digested, further
dropping the C/N. The rapid phase of composting may be over in a few
months, but ripening can be allowed to go on for many more months if
Feeding unripened compost to worms is perhaps the quickest way to
lower C/N and make a potent soil amendment. Once the high heat of
decomposition has passed and the heap is cooling, it is commonly
invaded by redworms, the same species used for vermicomposting
kitchen garbage. These worms would not be able to eat the high C/N
material that went into a heap, but after heating, the average C/N
has probably dropped enough to be suitable for them.
The municipal composting operation at Fallbrook, California makes
clever use of this method to produce a smaller amount of high-grade
product out of a larger quantity of low-grade ingredients. Mixtures
of sewage sludge and municipal solid waste are first composted and
after cooling, the half-done high C/N compost is shallowly spread
out over crude worm beds and kept moist. More crude compost is added
as the worms consume the waste, much like a household worm box. The
worm beds gradually rise. The lower portion of these mounds is pure
castings while the worm activity stays closer to the surface where
food is available. When the beds have grown to about three feet
tall, the surface few inches containing worms and undigested food
are scraped off and used to form new vermicomposting beds. The
castings below are considered finished compost. By laboratory
analysis, the castings contain three or four times as much nitrogen
as the crude compost being fed to the worms.
The marketplace gives an excellent indicator of the difference
between their crude compost and the worm casts. Even though
Fallbrook is surrounded by large acreages devoted to citrus orchards
and row crop vegetables, the municipality has a difficult time
disposing of the crude product. But their vermicompost is in strong
Sir Albert Howard's Indore Method
Nineteenth-century farmers and market gardeners had much practical
knowledge about using manures and making composts that worked like
fertilizers, but little was known about the actual microbial process
of composting until our century. As information became available
about compost ecology, one brilliant individual, Sir Albert Howard,
incorporated the new science of soil microbiology into his
composting and by patient experiment learned how to make superior
During the 1920s, Albert Howard was in charge of a government
research farm at Indore, India. At heart a Peace Corps volunteer, he
made Indore operate like a very representative Indian farm, growing
all the main staples of the local agriculture: cotton, sugar cane,
and cereals. The farm was powered by the same work oxen used by the
surrounding farmers. It would have been easy for Howard to
demonstrate better yields through high technology by buying chemical
fertilizers or using seed meal wastes from oil extraction, using
tractors, and growing new, high-yielding varieties that could make
use of more intense soil nutrition. But these inputs were not
affordable to the average Indian farmer and Howard's purpose was to
offer genuine help to his neighbors by demonstrating methods they
_could_ easily afford and use.
In the beginning of his work at Indore, Howard observed that the
district's soils were basically fertile but low in organic matter
and nitrogen. This deficiency seemed to be due to traditionally
wasteful practices concerning manures and agricultural residues. So
Howard began developing methods to compost the waste products of
agriculture, making enough high-quality fertilizer to supply the
entire farm. Soon, Indore research farm was enjoying record yields
without having insect or disease problems, and without buying
fertilizer or commercial seed. More significantly, the work animals,
fed exclusively on fodder from Indore's humus-rich soil, become
invulnerable to cattle diseases. Their shining health and fine
condition became the envy of the district.
Most significant, Howard contended that his method not only
conserved the nitrogen in cattle manure and crop waste, not only
conserved the organic matter the land produced, but also raised the
processes of the entire operation to an ecological climax of
maximized health and production. Conserving the manure and
composting the crop waste allowed him to increase the soil's organic
matter which increased the soil's release of nutrients from rock
particles that further increased the production of biomass which
allowed him to make even more compost and so on. What I have just
described is not surprising, it is merely a variation on good
farming that some humans have known about for millennia.
What was truly revolutionary was Howard's contention about
increasing net nitrates. With gentle understatement, Howard asserted
that his compost was genuinely superior to anything ever known
before. Indore compost had these advantages: no nitrogen or organic
matter was lost from the farm through mishandling of agricultural
wastes; the humus level of the farm's soils increased to a maximum
sustainable level; and, _the amount of nitrate nitrogen in the
finished compost was higher than the total amount of nitrogen
contained in the materials that formed the heap._ Indore compost
resulted in a net gain of nitrate nitrogen. The compost factory was
also a biological nitrate factory.
Howard published details of the Indore method in 1931 in a slim book
called _The Waste Products of Agriculture. _The widely read book
brought him invitations to visit plantations throughout the British
Empire. It prompted farmers world-wide to make compost by the Indore
method. Travel, contacts, and new awareness of the problems of
European agriculture were responsible for Howard's decision to
create an organic farming and gardening movement.
Howard repeatedly warned in _The Waste Products of Agriculture_ that
if the underlying fundamentals of his process were altered, superior
results would not occur. That was his viewpoint in 1931. However,
humans being what we are, it does not seem possible for good
technology to be broadcast without each user trying to improve and
adapt it to their own situation and understanding. By 1940, the term
"lndore compost" had become a generic term for any kind of compost
made in a heap without the use of chemicals, much as "Rototiller"
has come to mean any motor-driven rotarytiller.
Howard's 1931 concerns were correct--almost all alterations of the
original Indore system lessened its value--but Howard of 1941 did
not resist this dilutive trend because in an era of chemical farming
any compost was better than no compost, any return of humus better
Still, I think it is useful to go back to the Indore research farm
of the 1920s and to study closely how Albert Howard once made the
world's finest compost, and to encounter this great man's thoughts
before he became a crusading ideologue, dead set against any use of
agricultural chemicals. A great many valuable lessons are still
contained in _The Waste Products of Agriculture. _Unfortunately,
even though many organic gardeners are familiar with the later works
of Sir Albert Howard the reformer, Albert Howard the scientist and
researcher, who wrote this book, is virtually unknown today.
At Indore, all available vegetable material was composted, including
manure and bedding straw from the cattle shed, unconsumed crop
residues, fallen leaves and other forest wastes, weeds, and green
manures grown specifically for compost making. All of the urine from
the cattle shed-in the form of urine earth--and all wood ashes from
any source on the farm were also included. Being in the tropics,
compost making went on year-round. Of the result, Howard stated that
"The product is a finely divided leafmould, of high nitrifying
power, ready for immediate use [without temporarily inhibiting plant
growth]. The fine state of division enables the compost to be
rapidly incorporated and to exert its maximum influence on a very
large area of the internal surface of the soil."
Howard stressed that for the Indore method to work reliably the
carbon to nitrogen ratio of the material going into the heap must
always be in the same range. Every time a heap was built the same
assortment of crop wastes were mixed with the same quantities of
fresh manure and urine earth. As with my bread-baking analogy,
Howard insured repeatability of ingredients.
Any hard, woody materials--Howard called them "refractory"--must be
thoroughly broken up before composting, otherwise the fermentation
would not be vigorous, rapid, and uniform throughout the process.
This mechanical softening up was cleverly accomplished without power
equipment by spreading tough crop wastes like cereal straw or pigeon
pea and cotton stalks out over the farm roads, allowing cartwheels,
the oxens' hooves, and foot traffic to break them up.
Decomposition must be rapid and aerobic, but not too aerobic. And
not too hot. Quite intentionally, Indore compost piles were not
allowed to reach the highest temperatures that are possible. During
the first heating cycle, peak temperatures were about 140 degree.
After two weeks, when the first turn was made, temperatures had
dropped to about 125 degree, and gradually declined from there.
Howard cleverly restricted the air supply and thermal mass so as to
"bank the fires" of decomposition. This moderation was his key to
preventing loss of nitrogen. Provisions were made to water the heaps
as necessary, to turn them several times, and to use a novel system
of mass inoculation with the proper fungi and bacteria. I'll shortly
discuss each of these subjects in detail. Howard was pleased that
there was no need to accept nitrogen loss at any stage and that the
reverse should happen. Once the C/N had dropped sufficiently, the
material was promptly incorporated into the soil where nitrate
nitrogen will be best preserved. But the soil is not capable of
doing two jobs at once. It can't digest crude organic matter and
simultaneously nitrify humus. So compost must be finished and
completely ripe when it was tilled in so that:
". . . there must be no serious competition between the last stages
of decay of the compost and the work of the soil in growing the
crop. This is accomplished by carrying the manufacture of humus up
to the point when nitrification is about to begin. In this way the
Chinese principle of dividing the growing of a crop into two
separate processes--(1) the preparation of the food materials
outside the field, and (2) the actual growing of the crop-can be
introduced into general agricultural practice."
And because he actually lived on a farm, Howard especially
emphasized that composting must be sanitary and odorless and that
flies must not be allowed to breed in the compost or around the work
cattle. Country life can be quite idyllic--without flies.
The Indore Compost Factory
At Indore, Howard built a covered, open-sided, compost-making
factory that sheltered shallow pits, each 30 feet long by 14 feet
wide by 2 feet deep with sloping sides. The pits were sufficiently
spaced to allow loaded carts to have access to all sides of any of
them and a system of pipes brought water near every one. The
materials to be composted were all stored adjacent to the factory.
Howard's work oxen were conveniently housed in the next building.
Soil and Urine Earth
Howard had been raised on an English farm and from childhood he had
learned the ways of work animals and how to make them comfortable.
So, for the ease of their feet, the cattle shed and its attached,
roofed loafing pen had earth floors. All soil removed from the
silage pits, dusty sweepings from the threshing floors, and silt
from the irrigation ditches were stored near the cattle shed and
used to absorb urine from the work cattle. This soil was spread
about six inches deep in the cattle stalls and loafing pen. About
three times a year it was scraped up and replaced with fresh soil,
the urine-saturated earth then was dried and stored in a special
covered enclosure to be used for making compost.
The presence of this soil in the heap was essential. First, the
black soil of Indore was well-supplied with calcium, magnesium, and
other plant nutrients. These basic elements prevented the heaps from
becoming overly acid. Additionally, the clay in the soil was
uniquely incorporated into the heap so that it coated everything.
Clay has a strong ability to absorb ammonia, preventing nitrogen
loss. A clay coating also holds moisture. Without soil, "an even and
vigorous mycelial growth is never quickly obtained." Howard said
"the fungi are the storm troops of the composting process, and must
be furnished with all the armament they need."
Crop wastes were protected from moisture, stored dry under cover
near the compost factory. Green materials were first withered in the
sun for a few days before storage. Refractory materials were spread
on the farm's roads and crushed by foot traffic and cart wheels
before stacking. All these forms of vegetation were thinly layered
as they were received so that the dry storage stacks became
thoroughly mixed. Care was taken to preserve the mixing by cutting
vertical slices out of the stacks when vegetation was taken to the
compost pits. Howard said the average C/N of this mixed vegetation
was about 33:1. Every compost heap made year-round was built with
this complex assortment of vegetation having the same properties and
the same C/N.
Special preliminary treatment was given to hard, woody materials
like sugarcane, millet stumps, wood shavings and waste paper. These
were first dumped into an empty compost pit, mixed with a little
soil, and kept moist until they softened. Or they might be soaked in
water for a few days and then added to the bedding under the work
cattle. Great care was taken when handling the cattle's bedding to
insure that no flies would breed in it.
Though crop wastes and urine-earth could be stored dry for later
use, manure, the key ingredient of Indore compost, had to be used
fresh. Fresh cow dung contains bacteria from the cow's rumen that is
essential to the rapid decomposition of cellulose and other dry
vegetation. Without their abundant presence composting would not
begin as rapidly nor proceed as surely.
Charging the Compost Pits
Every effort was made to fill a pit to the brim within one week. If
there wasn't enough material to fill an entire pit within one week,
then a portion of one pit would be filled to the top. To preserve
good aeration, every effort was made to avoid stepping on the
material while filling the pit. As mixtures of manure and bedding
were brought out from the cattle shed they were thinly layered atop
thin layers of mixed vegetation brought in from the dried reserves
heaped up adjacent to the compost factory. Each layer was thoroughly
wet down with a clay slurry made of three ingredients: water,
urine-earth, and actively decomposing material from an adjacent
compost pit that had been filled about two weeks earlier. This
insured that every particle within the heap was moist and was coated
with nitrogen-rich soil and the microorganisms of decomposition.
Today, we would call this practice "mass inoculation."
Pits Versus Heaps
India has two primary seasons. Most of the year is hot and dry while
the monsoon rains come from dune through September. During the
monsoon, so much water falls so continuously that the earth becomes
completely saturated. Even though the pits were under a roof, they
would fill with water during this period. So in the monsoon, compost
was made in low heaps atop the ground. Compared to the huge pits,
their dimensions were smaller than you would expect: 7 x 7 feet at
the top, 8 x 8 feet at the base and no more than 2 feet high. When
the rains started, any compost being completed in pits was
transferred to above-ground heaps when it was turned.
Howard was accomplishing several things by using shallow pits or low
but very broad heaps. One, thermal masses were reduced so
temperatures could not reach the ultimate extremes possible while
composting. The pits were better than heaps because air flow was
further reduced, slowing down the fermentation, while their
shallowness still permitted sufficient aeration. There were enough
covered pits to start a new heap every week.
Temperature Range in Normal Pit
Age in days Temperature in degree C
Period in days for each fall of 5i C
Temperature Range No. of Days
65 degree-60 degree 4
60 degree-55 degree 7
55 degree-50 degree 1
50 degree-45 degree 25
45 degree-40 degree 2
40 degree-35 degree 44
35 degree-30 degree 14
Total 97 days
_Turning the compost_ was done three times: To insure uniform
decomposition, to restore moisture and air, and to supply massive
quantities of those types of microbes needed to take the composting
process to its next stage.
The first turn was at about sixteen days. A second mass inoculation
equivalent to a few wheelbarrows full of 30 day old composting
material was taken from an adjacent pit and spread thinly over the
surface of the pit being turned. Then, one half of the pit was dug
out with a manure fork and placed atop the first half. A small
quantity of water was added, if needed to maintain moisture. Now the
compost occupied half the pit, a space about 15 x 14 and was about
three feet high, rising out of the earth about one foot. During the
monsoons when heaps were used, the above-ground piles were also mass
inoculated and then turned so as to completely mix the material, and
as we do today, placing the outside material in the core and
One month after starting, or about two weeks after the first turn,
the pit or heap would be turned again. More water would be added.
This time the entire mass would be forked from one half the pit to
the other and every effort would be made to fluff up the material
while thoroughly mixing it. And a few loads of material were removed
to inoculate a 15-day-old pit.
Another month would pass, or about two months after starting, and
for the third time the compost would be turned and then allowed to
ripen. This time the material is brought out of the pit and piled
atop the earth so as to increase aeration. At this late stage there
would be no danger of encouraging high temperatures but the
increased oxygen facilitated nitrogen fixation. The contents of
several pits might be combined to form a heap no larger than 10 x 10
at the base, 9 x 9 on top, and no more than 3-1/2 feet high. Again,
more water might be added. Ripening would take about one month.
Howard's measurements showed that after a month's maturation the
finished compost should be used without delay or precious nitrogen
would be lost. However, keep in mind when considering this brief
ripening period that the heap was already as potent as it could
become. Howard's problem was not further improving the C/N, it was
conservation of nitrogen.
The Superior Value of Indore Compost.
Howard said that finished Indore compost was twice as rich in
nitrogen as ordinary farmyard manure and that his target was compost
with a C/N of 10:1. Since it was long manure he was referring to,
let's assume that the C/N of a new heap started at 25:1.
The C/N of vegetation collected during the year is highly variable.
Young grasses and legumes are very high in nitrogen, while dried
straw from mature plants has a very high C/N. If compost is made
catch-as-catch-can by using materials as they come available, then
results will be highly erratic. Howard had attempted to make
composts of single vegetable materials like cotton residues, cane
trash, weeds, fresh green sweet clover, or the waste of field peas.
These experiments were always unsatisfactory. So Howard wisely mixed
his vegetation, first withering and drying green materials by
spreading them thinly in the sun to prevent their premature
decomposition, and then taking great care to preserve a uniform
mixture of vegetation types when charging his compost pits. This
strategy can be duplicated by the home gardener. Howard was
surprised to discover that he could compost all the crop waste he
had available with only half the urine earth and about one-quarter
of the oxen manure he had available. But fresh manure and urine
earth were essential.
During the 1920s a patented process for making compost with a
chemical fertilizer called Adco was in vogue and Howard tried it. Of
using chemicals he said:
"The weak point of Adco is that it does nothing to overcome one of
the great difficulties in composting, namely the absorption of
moisture in the early stages. In hot weather in India, the Adco pits
lose moisture so rapidly that the fermentation stops, the
temperature becomes uneven and then falls. When, however, urine
earth and cow-dung are used, the residues become covered with a thin
colloidal film, which not only retains moisture but contains
combined nitrogen and minerals required by the fungi. This film
enables the moisture to penetrate the mass and helps the fungi to
establish themselves. Another disadvantage of Adco is that when this
material is used according to the directions, the carbon-nitrogen
ratio of the final product is narrower than the ideal 10:1. Nitrogen
is almost certain to be lost before the crop can make use of it"
Fresh cow manure contains digestive enzymes and living bacteria that
specialize in cellulose decomposition. Having a regular supply of
this material helped initiate decomposition without delay.
Contributing large quantities of actively growing microorganisms
through mass inoculation with material from a two-week-old pile also
helped. The second mass inoculation at two weeks, with material from
a month-old heap provided a large supply of the type of organisms
required when the heap began cooling. City gardeners without access
to fresh manure may compensate for this lack by imitating Howard's
mass inoculation technique, starting smaller amounts of compost in a
series of bins and mixing into each bin a bit of material from the
one further along at each turning. The passive backyard composting
container automatically duplicates this advantage. It simultaneously
contains all decomposition stages and inoculates the material above
by contact with more decomposed material below. Using prepared
inoculants in a continuous composting bin is unnecessary.
City gardeners cannot readily obtain urine earth. Nor are American
country gardeners with livestock likely to be willing to do so much
work. Remember that Howard used urine earth for three reasons. One,
it contained a great deal of nitrogen and improved the starting C/N
of the heap. Second, it is thrifty. Over half the nutrient content
of the food passing through cattle is discharged in the urine. But,
equally important, soil itself was beneficial to the process. Of
this Howard said, "[where] there may be insufficient dung and urine
earth for converting large quantities of vegetable wastes which are
available, the shortage may be made up by the use of nitrate of soda
. . . If such artificials are employed, it will be a great advantage
to make use of soil." I am sure he would have made very similar
comments about adding soil when using chicken manure, or organic
concentrates like seed meals, as cattle manure substitutes.
Control of the air supply is the most difficult part of composting.
First, the process must stay aerobic. That is one reason that
single-material heaps fail because they tend to pack too tightly. To
facilitate air exchange, the pits or heaps were never more than two
feet deep. Where air was insufficient (though still aerobic) decay
is retarded but worse, a process called denitrification occurs in
which nitrates and ammonia are biologically broken down into gasses
and permanently lost. Too much manure and urine-earth can also
interfere with aeration by making the heap too heavy, establishing
anaerobic conditions. The chart illustrates denitrification caused
by insufficient aeration compared to turning the composting process
into a biological nitrate factory with optimum aeration.
Making Indore Compost in Deep and Shallow Pits
Pit 4 feet deep Pit 2 feet deep
Amount of material (lb. wet)
in pit at start 4,500 4,514
Total nitrogen (lb) at start 31.25 29.12
Total nitrogen at end 29.49 32.36
Loss or gain of nitrogen (lb) -1.76 +3.24
Percentage loss or gain of nitrogen -6.1% +11.1%
Finally, modern gardeners might reconsider limiting temperature
during composting. India is a very warm climate with balmy nights
most of the year. Heaps two or three feet high will achieve an
initial temperature of about 145 degree. The purchase of a
thermometer with a long probe and a little experimentation will show
you the dimensions that will more-or-less duplicate Howard's
temperature regimes in your climate with your materials.
Howard's technique of mass inoculation with large amounts of
biologically active material from older compost heaps speeds and
directs decomposition. It supplies large numbers of the most useful
types of microorganisms so they dominate the heap's ecology before
other less desirable types can establish significant populations. I
can't imagine how selling mass inoculants could be turned into a
But just imagine that seeding a new heap with tiny amounts of
superior microorganisms could speed initial decomposition and result
in a much better product. That _could _be a business. Such an
approach is not without precedent. Brewers, vintners, and bread
makers all do that. And ever since composting became interesting to
twentieth-century farmers and gardeners, entrepreneurs have been
concocting compost starters that are intended to be added by the
ounce(s) to the cubic yard.
Unlike the mass inoculation used at Indore, these inoculants are a
tiny population compared to the microorganisms already present in
any heap. In that respect, inoculating compost is very different
than beer, wine, or bread. With these food products there are few or
no microorganisms at the start. The inoculant, small as it might be,
still introduces millions of times more desirable organisms than
those wild types that might already be present.
But the materials being assembled into a new compost heap are
already loaded with microorganism. As when making sauerkraut, what
is needed is present at the start. A small packet of inoculant is
not likely to introduce what is not present anyway. And the complex
ecology of decomposition will go through its inevitable changes as
the microorganisms respond to variations in temperature, aeration,
This is one area of controversy where I am comfortable seeking the
advice of an expert. In this case, the authority is Clarence
Golueke, who personally researched and developed U.C. fast
composting in the early 1950s, and who has been developing municipal
composting systems ever since. The bibliography of this book lists
two useful works by Golueke.
Golueke has run comparison tests of compost starters of all sorts
because, in his business, entrepreneurs are constantly attempting to
sell inoculants to municipal composting operations. Of these
vendors, Golueke says with thinly disguised contempt:
"Most starter entrepreneurs include enzymes when listing the
ingredients of their products. The background for this inclusion
parallels the introduction of purportedly advanced versions of
starters-i.e., "advanced" in terms of increased capacity, utility
and versatility. Thus in the early 1950's (when [I made my]
appearance on the compost scene), starters were primarily microbial
and references to identities of constituent microbes were very
vague. References to enzymes were extremely few and far between. As
early ("pioneer") researchers began to issue formal and informal
reports on microbial groups (e.g., actinomycetes) observed by them,
they also began to conjecture on the roles of those microbial groups
in the compost process. The conjectures frequently were accompanied
by surmises about the part played by enzymes.
Coincidentally, vendors of starters in vogue at the time began to
claim that their products included the newly reported microbial
groups as well as an array of enzymes. For some reason, hormones
were attracting attention at the time, and so most starters were
supposedly laced with hormones. In time, hormones began to disappear
from the picture, whereas enzymes were given a billing parallel to
that accorded to the microbial component."
Golueke has worked out methods of testing starters that eliminates
any random effects and conclusively demonstrates their result.
Inevitably, and repeatedly, he found that there was no difference
between using a starter and not using one. And he says, "Although
anecdotal accounts of success due to the use of particular inoculum
are not unusual in the popular media, we have yet to come across
unqualified accounts of successes in the refereed scientific and
technical literature." I use a variation of mass inoculation when
making compost. While building a new heap, I periodically scrape up
and toss in a few shovels of compost and soil from where the
previous pile was made. Frankly, if I did not do this I don't think
the result would be any worse.
On composting and soil organic matter
_Workshop on the Role of Earthworms in the Stabilization of Organic
Residues, Vol. I and II._ Edited by Mary Appelhof. Kalamazoo,
Michigan: Beech Leaf Press of the Kalamazoo Nature Center, 1981. If
ever there was a serious investigation into the full range of the
earthworm's potential to help Homo Sapiens, this conference explored
it. Volume II is the most complete bibliography ever assembled on
Appelhof, Mary. _Worms Eat My Garbage._ Kalamazoo, Michigan: Flower
Press, 1982. A delightful, slim, easy reading, totally positive book
that offers enthusiastic encouragement to take advantage of
Barrett, Dr. Thomas J. _Harnessing the Earthworm._ Boston: Wedgewood
_The Biocycle Guide to the Art & Science of Composting._ Edited by
the Staff of _Biocycle: Journal of Waste Recycling._ Emmaus,
Pennsylvania: J.G. Press, 1991. The focus of this book is on
municipal composting and other industrial systems. Though imprinted
"Emmaus" this is not the Rodale organization, but a group that
separated from Rodale Press over ten years ago. included on the
staff are some old _Organic Gardening and Farming_ staffers from the
1970s, including Gene Logdson and Jerome Goldstein. A major section
discussing the biology and ecology of composting is written by
Clarence Golueke. There are articles about vermicomposting,
anaerobic digestion and biogasification, and numerous descriptions
of existing facilities.
Campbell, Stu. _Let It Rot! _Pownal, Vermont: Storey Communications,
Inc., 1975. Next to my book, the best in-print at-home compost
Darwin, Charles R. _The Formation of Vegetable Mould through the
Action of Worms with Observations on their Habits._ London: John
Murray & Co., 1881.
Dindal, Daniel L. _Ecology of Compost._ Syracuse, New York: N.Y.
State Council of Environmental Advisors and SUNY College of
Environmental Science and Forestry, 1972. Actually, a little booklet
but very useful.
Golueke, Clarence G., Ph.D. _Composting: A Study of the Process and
its Principles._ Emmaus: Rodale Press, 1972. Golueke, writing in
"scientific" says much of what my book does in one-third as many
words that are three times as long. He is America's undisputed
authority on composting.
Hopkins, Donald P. _Chemicals, Humus and the Soil._ Brooklyn:
Chemical Publishing Company, 1948. Any serious organic gardener
should confront Donald Hopkins' thoughtful critique of Albert
Howard's belief system. This book demolishes the notion that
chemical fertilizers are intrinsically harmful to soil life while
correctly stressing the vital importance of humus.
Hopp, Henry. _What Every Gardener Should Know About Earthworms.
_Charlotte, Vermont: Garden Way Publishing Company, 1973. Hopp was a
world-recognized expert on the earthworm.
Howard, Albert and Yeshwant D. Wad. _The Waste Products of
Agriculture: Their Utilization as Humus. _London: Oxford University
Press, 1931. Many organic gardeners have read Howard's _An
Agricultural Testament, _but almost none have heard of this book. It
is the source of my information about the original Indore composting
_An Agricultural Testament._ London & New York: Oxford
University Press, 1940. Describes Howard's early crusade to restore
humus to industrial farming.
_The Soil and Health._ New York: Devin Adair, 1947. Also
published in London by Faber & Faber, titled _Farming and Gardening
for Health or Disease._ A full development of Howard's theme that
humus is health for plants, animals and people.
Howard, Louise E. _The Earth's Green Carpet._ Emmaus: Rodale Press,
1947. An oft-overlooked book by Howard's second wife. This one, slim
volume expresses with elegant and passionate simplicity all of the
basic beliefs of the organic gardening and farming movement. See
also her _Albert Howard in India._
Kevan, D. Keith. _Soil Animals. _London: H. F. & G. Witherby Ltd.,
1962. Soil zoology for otherwise well-schooled layreaders.
King, F.H. _Farmers of Forty Centuries or Permanent Agriculture in
China, Korea and Japan._ Emmaus: Rodale Press, first published 1911.
Treasured by the organic gardening movement for its description of a
long-standing and successful agricultural system based completely on
composting. It is a great travel/adventure book.
Koepf, H.H., B.D. Petterson, and W. Shaumann. _Bio-Dynamic
Agriculture: An Introduction. _Spring Valley, New York:
Anthroposophic Press, 1976. A good introduction to this
philosophical/mystical system of farming and gardening that uses
magical compost inoculants.
Krasilnikov, N A. _Soil Microorganisms and Higher Plants.
_Translated by Y.A. Halperin. Jerusalem: Israel Program for
Scientific Translations, 1961. Organic gardeners have many vague
beliefs about how humus makes plants healthy. This book
scientifically explains why organic matter in soil makes plants
healthy. Unlike most translations of Russian, this one is an easy
Kuhnelt, Wilhelm. _Soil Biology: with special reference to the
animal kingdom. _East Lansing: Michigan State University Press,
1976. Soil zoology at a level assuming readers have university-level
biology, zoology and microbiology. Still, very interesting to
well-read lay persons who are not intimidated by Latin taxonomy.
Minnich, Jerry. _The Earthworm Book: How to Raise and Use Earthworms
for Your Farm and Garden. _Emmaus: Rodale Press, 1977. This book is
a thorough and encyclopedic survey of the subject
Minnich, Jerry and Marjorie Hunt. _The Rodale Guide to Composting.
_Emmaus, Pennsylvania: Rodale Press, 1979. A very complete survey of
composting at home, on the farm, and in municipalities. The book has
been through numerous rewritings since the first edition; this
version is the best. It is more cohesive and less seeming like it
was written by a committee than the version in print now. _Organic
Gardening and Farming _magazine may have been at its best when
Minnich was a senior editor.
Oliver, George Sheffield. _Our Friend the Earthworm. _Library no.
26. Emmaus: Rodale Press, 1945. During the 1940s Rodale Press issued
an inexpensive pamphlet library; this is one of the series.
Pfeiffer, E.E. _Biodynamic Farming and Gardening. _Spring Valley,
New York: Anthroposophic Press, 1938.
Poincelot, R.P. _The Biochemistry and Methodology of Composting.
_Vol. Bull. 727. Conn. Agric. Expt. Sta., 1972. A rigorous but
readable review of scientific literature and known data on
composting through 1972 including a complete bibliography.
Russell, Sir E. John. _Soil Conditions and Plant Growth._ Eighth
Ed., New York: Longmans, Green & Co., 1950. The best soil science
text I know of. Avoid the recent in-print edition that has been
revised by a committee of current British agronomists. They enlarged
Russell's book and made more credible to academics by making it less
comprehensible to ordinary people with good education and
intelligence through the introduction of unnecessary mathematical
models and stilted prose. it lacks the human touch and simpler
explanations of Russell's original statements.
Schaller, Friedrich. _Soil Animals. _Ann Arbor: University of
Michigan, 1968. Soil zoology for American readers without extensive
scientific background. Shaler was Kuhnelt's student.
Stout, Ruth. _Gardening Without Work: For the Aging, the Busy and
the Indolent._ Old Greenwich, Connecticut: Devin Adair, 1961. The
original statement of mulch gardening. Fun to read. Her disciple,
Richard Clemence, wrote several books in the late 1970s that develop
the method further.
Of interest to the serious food gardener
I have learned far more from my own self-directed studies than my
formal education. From time to time I get enthusiastic about some
topic and voraciously read about it. When I started gardening in the
early 1970s l quickly devoured everything labeled "organic" in the
local public library and began what became a ten-year subscription
to _Organic Gardening and Farming_ magazine. During the early 1980s
the garden books that I wrote all had the word "organic" in the
In the late 1980s my interest turned to what academics might call
'the intellectual history of radical agriculture.' I reread the
founders of the organic gardening and farming movement, only to
discover that they, like Mark Twain's father, had become far more
intelligent since l last read them fifteen years back. l began to
understand that one reason so many organic gardeners misunderstood
Albert Howard was that he wrote in English, not American. l also
noticed that there were other related traditions of agricultural
reform and followed these back to their sources. This research took
over eighteen months of heavy study. l really gave the interlibrary
loan librarian a workout.
Herewith are a few of the best titles l absorbed during that
research. l never miss an opportunity to help my readers discover
that older books were written in an era before all intellectuals
were afflicted with lifelong insecurity caused by cringing from an
imaginary critical and nattery college professor standing over their
shoulder. Older books are often far better than new ones, especially
if you'll forgive them an occasional error in point of fact. We are
not always discovering newer, better, and improved. Often we are
forgetting and obscuring and confusing what was once known, clear
and simple. Many of these extraordinary old books are not in print
and not available at your local library. However, a simple inquiry
at the Interlibrary Loan desk of most libraries will show you how
easy it is to obtain these and most any other book you become
Albrecht, William A. _The Albrecht Papers, Vols 1 &2._ Kansas City:
Acres, USA 1975.
Albert Howard, Weston Price, Sir Robert McCarrison, and William
Albrecht share equal responsibility for creating this era's movement
toward biologically sound agriculture. Howard is still well known to
organic gardeners, thanks to promotion by the Rodale organization
while Price, McCarrison, and Albrecht have faded into obscurity.
Albrecht was chairman of the Soil Department at the University of
Missouri during the 1930s. His unwavering investigation of soil
fertility as the primary cause of health and disease was considered
politically incorrect by the academic establishment and vested
interests that funded agricultural research at that time. Driven
from academia, he wrote prolifically for nonscientific magazines and
lectured to farmers and medical practitioners during the 1940s and
1950s. Albrecht was willing to consider chemical fertilizers as
potentially useful though he did not think chemicals were as
sensible as more natural methods. This view was unacceptable to J.l.
Rodale, who ignored Albrecht's profound contributions.
Balfour, Lady Eve B. _The Living Soil._ London: Faber and Faber,
Lady Balfour was one of the key figures in creating the organic
gardening and farming movement. She exhibited a most remarkable
intelligence and understanding of the science of health and of the
limitations of her own knowledge. Balfour is someone any serious
gardener will want to meet through her books. Lady Balfour proved
Woody Allen right about eating organic brown rice; she died only
recently in her late 90s, compus mentis to the end.
Borsodi, Ralph. _Flight from the City: An Experiment in Creative
Living on the Land._ New York: Harper and Brothers, 1933.
A warmly human back-to-the-lander whose pithy critique of industrial
civilization still hits home. Borsodi explains how production of
life's essentials at home with small-scale technology leads to
enhanced personal liberty and security. Homemade is inevitably more
efficient, less costly, and better quality than anything
mass-produced. Readers who become fond of this unique
individualist's sociology and political economy will also enjoy
Borsodi's _This Ugly Civilization _and _The Distribution Age._
Brady, Nyle C. _The Nature and Properties of Soils, _Eighth Edition.
New York: Macmillan, 1974.
Through numerous editions and still the standard soils text for
American agricultural colleges. Every serious gardener should
attempt a reading of this encyclopedia of soil knowledge every few
years. See also Foth, Henry D. _Fundamentals of Soil Science._
Bromfield, Louis. _Malibar Farm._ New York: Harper & Brothers, 1947.
Here is another agricultural reformer who did not exactly toe the
Organic Party line as promulgated by J.l. Rodale. Consequently his
books are relatively unknown to today's gardening public. If you
like Wendell Berry you'll find Bromfield's emotive and Iyrical prose
even finer and less academically contrived. His experiments with
ecological farming are inspiring. See also Bromfield's other farming
books: _Pleasant Valley, In My Experience,_ and _Out of the Earth._
Carter, Vernon Gill and Dale, Tom. _Topsoil and Civilization.
_Norman: University of Oklahoma Press, 1974. (first edition, 1954)
This book surveys seven thousand years of world history to show how
each place where civilization developed was turned into an
impoverished, scantily-inhabited semi-desert by neglecting soil
conservation. Will ours' survive any better? Readers who wish to
pursue this area further might start with Wes Jackson's _New Roots
Ernle, (Prothero) Lord. _English Farming Past and Present,_ 6th
edition. First published London: Longmans, Green & Co., Ltd., 1912,
and many subsequent editions. Chicago: Quadrangle Books, 1962.
Some history is dry as dust. Ernle's writing lives like that of
Francis Parkman or Gibbon. Anyone serious about vegetable gardening
will want to know all they can about the development of modern
Foth, Henry D. _Fundamentals of Soil Science, _Eighth Edition. New
York: John Wylie & Sons, 1990.
Like Brady's text, this one has also been through numerous editions
for the past several decades. Unlike Brady's work however, this book
is a little less technical, an easier read as though designed for
non-science majors. Probably the best starter text for someone who
wants to really understand soil.
Hall, Bolton. _Three Acres and Liberty. _New York: Macmillan, 1918.
Bolton Hall marks the start of our modern back-to-the-land movement.
He was Ralph Borsodi's mentor and inspiration. Where Ralph was
smooth and intellectual, Hall was crusty and Twainesque.
Hamaker, John. D. _The Survival of Civilization. _Annotated by
Donald A. Weaver. Michigan/ California: Hamaker-Weaver Publishers,
Forget global warming, Hamaker believably predicts the next ice age
is coming. Glaciers will be upon us sooner than we know unless we
reverse intensification of atmospheric carbon dioxide by
remineralization of the soil. Very useful for its exploration of the
agricultural use of rock flours. Helps one stand back from the
current global warming panic and ask if we really know what is
coming. Or are we merely feeling guilty for abusing Earth?
Hopkins, Cyril G. _Soil Fertility and Permanent Agriculture.
_Boston: Ginn and Company, 1910.
Though of venerable lineage, this book is still one of the finest of
soil manuals in existence. Hopkins' interesting objections to
chemical fertilizers are more economic than moral.
_The Story of the Soil: From the Basis of Absolute Science and Real
Life. _Boston: Richard G. Badger, 1911.
A romance of soil science similar to Ecotopia or Looking Backward.
No better introduction exists to understanding farming as a process
of management of overall soil mineralization. People who attempt
this book should be ready to forgive that Hopkins occasionally
expresses opinions on race and other social issues that were
acceptable in his era but today are considered objectionable by most
Jenny, Hans. _Factors of Soil Formation: a System of Quantitative
Pedology._ New York: McGraw Hill, 1941.
Don't let the title scare you. Jenny's masterpiece is not hard to
read and still stands in the present as the best analysis of how
soil forms from rock. Anyone who is serious about growing plants
will want to know this data.
McCarrison, Sir Robert. _The Work of Sir Robert McCarrison. _ed. H.
M. Sinclair. London Faber and Faber, 1953.
One of the forgotten discoverers of the relationship between soil
fertility and human health. McCarrison, a physician and medical
researcher, worked in India contemporaneously with Albert Howard. He
spent years "trekking around the Hunza and conducted the first
bioassays of food nutrition by feeding rat populations on the
various national diets of India. And like the various nations of
India, some of the rats became healthy, large, long-lived, and good
natured while others were small, sickly, irritable, and short-lived.
Nearing, Helen & Scott. _Living the Good Life: How to Live Sanely
and Simply in a Troubled World._ First published in 1950. New York:
Schocken Books, 1970.
Continuing in Borsodi's footsteps, the Nearings homesteaded in the
thirties and began proselytizing for the self-sufficient life-style
shortly thereafter. Scott was a very dignified old political radical
when he addressed my high school in Massachusetts in 1961 and
inspired me to dream of country living. He remained active until
nearly his hundredth birthday. See also: _Continuing the Good Life_
and _The Maple Sugar Book._
Parnes, Robert. _Organic and Inorganic Fertilizers. _Mt. Vernon,
Maine: Woods End Agricultural Institute, 1986.
Price, Weston A. _Nutrition and Physical Degeneration. _La Mesa,
California: Price-Pottenger Nutrition Foundation, reprinted 1970.
Sits on the "family bible" shelf in my home along with Albrecht,
McCarrison, and Howard. Price, a dentist with strong interests in
prevention, wondered why his clientele, 1920s midwest bourgeoisie,
had terrible teeth when prehistoric skulls of aged unlettered
savages retained all their teeth in perfect condition. So he
traveled to isolated parts of the Earth in the early 1930s seeking
healthy humans. And he found them--belonging to every race and on
every continent. And found out why they lived long, had virtually no
degeneration of any kind including dental degeneration. Full of
interesting photographs, anthropological data, and travel details. A
trail-blazing work that shows the way to greatly improved human
Rodale, J.I. _The Organic Front._ Emmaus: Rodale Press, 1948.
An intensely ideological statement of the basic tenets of the
Organic faith. Rodale established the organic gardening and farming
movement in the United States by starting up _Organic Gardening and
Farming_ magazine in 1942. His views, limitations and preferences
have defined "organic" ever since. See also: _Pay Dirt._
Schuphan, Werner. _Nutritional Values in Crops and Plants. _London:
Faber and Faber, 1965.
A top-rate scientist asks the question: "Is organically grown food
really more nutritious?" The answer is: "yes, and no."
Smith, J. Russell. _Tree Crops: A Permanent Agriculture._ New York:
Harcourt, Brace and Company, 1929.
No bibliography of agricultural alternatives should overlook this
classic critique of farming with the plow. Delightfully original!
Solomon, Steve. _Growing Vegetables West of the Cascades._ Seattle,
Washington: Sasquatch Books, 1989.
My strictly regional focus combined with the reality that the
climate west of the Cascades is radically different than the rest of
the United States has made this vegetable gardening text virtually
unknown to American gardeners east of the Cascades. It has been
praised as the best regional garden book ever written. Its analysis
of soil management, and critique of Rodale's version of the organic
gardening and farming philosophy are also unique. I founded and ran
Territorial Seed Company, a major, mail-order vegetable garden seed
business; no other garden book has ever encompassed my experience
with seeds and the seed world.
_Waterwise Gardening. _Seattle, Sasquatch Books, 1992.
How to grow vegetables without dependence on irrigation. Make your
vegetables able to survive long periods of drought and still be very
productive. My approach is extensive, old fashioned and contrarian,
the opposite of today's intensive, modern, trendy postage-stamp
Turner, Frank Newman. _Fertility, Pastures and Cover Crops Based on
Nature's Own Balanced Organic Pasture Feeds._ reprinted from: Faber
and Faber, 1955. ed., San Diego: Rateaver, 1975.
An encouragement to farm using long rotations and green manuring
systems from a follower of Albert Howard. Turner offered a
remarkably sensible definition for soil fertility, in essence, "if
my livestock stay healthy, live long, breed well, and continue doing
so for at least four generations, then my soil was fertile."
Voisin, Andre. _Better Grassland Sward. _London: Crosby Lockwood and
Sons, Ltd., 1960.
The first half is an amazing survey of the role of the earthworm in
soil fertility. The rest is just Voisin continuing on at his amazing
best. No one interested in soil and health should remain unfamiliar
with Voisin's intelligence. See also: _Grass Tetany, Grass
Productivity,_ and _Soil, Grass and Cancer._