ORGANIC GARDENER'S COMPOSTING TEXT

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 demand. 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 compost 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 than none. 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 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. Manure 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 3 63 4 60 6 58 11 55 12 53 13 49 14 49 _First Turn_ 18 49 20 51 22 48 24 47 29 46 _Second Turn_ 37 49 38 45 40 40 43 39 57 39 _Third Turn_ 61 41 66 39 76 38 82 36 90 33 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 _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 vice-versa. 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