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 are drawbacks.

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 before loading.

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 composter.

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 the bottom.

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 California.

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 water.

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 hand tools.

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 compaction.

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 selects.

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.

Sheet Composting

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 harmful effect.

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.

Mulch Gardening

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 grow vegetables.

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 year.

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 results.

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 are:

Kemp Company. 160 Koser Road., Lititz, PA 17543. (also compost drums)

Troy-Bilt Manufacturing Company, 102D St. & 9th Ave., Troy, NY 12180

Mail-order catalog sources of compost containers and garden accessories

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



CHAPTER SIX

Vermicomposting



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 said:

"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 yours, too."

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 a difficulty.

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.

Containers

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 inches deep.

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

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.

Soil

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 worms.

Redworms

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 laid.

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 casts.

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 vermicomposting?

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 moderately hard.

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 cut worms.

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 sour smell.

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 worms.

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 disturbed.

Seasonal Overloads

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, undernourished worms."

Vacations

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

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.

Maintenance

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 castings.

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 on it.

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 fresh bedding.

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 bedding.

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.

PART TWO

Composting For The Food Gardener

Introduction

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, advise:

"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 observed:

"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 ideology.

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 intervention.

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 loss.

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 stuff."

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' arguments.

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 ambiguity.

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 humans.

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 Organic Gardening.

Today's Confusions

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.



CHAPTER SEVEN

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 state.

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 better.

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.