Organic Gardener's Composting

l Compos

pose and humus will eventually form but, without heat, the process can take a long, long time. Getting a pile to heat up p

ng is to continue the pile must allow its living inhabitants sufficient air to breath. Hot piles tend to dry out rapidly, but must be kept moist

incorrectly there can be problems with odor and flies. Th

Comp

nd the primary agents of decomposition are soil animals. Bacteria and other microorganisms are secondary. In a compost pile the opposite occurs: we substitute

rs every twenty to thirty minutes, increasing geometrically: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1,024, 2,048, 4,

ellular burning does not happen violently with flame and light. Living things use enzymes to break complex organic molecules down into simpler ones like sugar (and others) and then enzyma

their food, and consequently radiate heat. When working hard, living things give off more heat; when resting, less. The ebb and flow of heat production matches their oxyg

ture. However, compostable materials do not transfer heat readily. In the language of architecture and home building they might be said to have a high "R" value or to be good insulat

chemistry constant by holding their body temperature steady. Most animals and all microorganisms have no ability to regulate their internal temperature; when they

f garden seed, the time it takes seed to germinate and the storage of food in the refrigerator. At the temperature of frozen water most living chemical pr

les with each 20 degree increase of temperature. So, at 70 degree F decomposition is running at twice the rate it does at 50 degree, while at 90 degree four times as rapidly as at 50 degree and so on. However, when temperat

inorganic chemical reactions accelerate with increases in temperature almost without limit, those processes conducted by living things usually have a much lower terminal temperature. Above some poi

e waiting in the cooler outer layers of the heap to reoccupy the core once things cool down. However, there are unique bacteria and fungi that only work effectively at temperatures exceeding 110 degree. Soil scientists and other acad

ambient temperature increases generate even more heat, the ultimate temperature is reached when the pile gets so hot that even thermophilic organisms begin to d

ulator. If the bales in the center of a large hay stack are just moist enough to encourage rapid bacterial decomposition, the heat generated may incr

mposter controls a number of factors. These are so

secrete digestive enzymes that break down and then dissolve organic matter. Some larger single-cell creatures can surround or

microorganisms multiply to consume the food supply. And the more heat is created. As particle size decreases, the amount of surface a

materials. Although compost heaps are made of much larger particles than soil, the relationship between particle size and surface area is the same. Clearly,

material to di

ccelerate d

h higher te

ot requiring oxygen. Anaerobic chemistry is slow and does not generate much heat, so a pile that suddenly cools off is giving a strong indication that the core may lack air. The primary waste products of aerobes are water and carbon dioxide gas-inoffensive substances. When most people think of putrefaction they are actually picturing decomposition by anaerobic bacteria. Wit

y draws in a supply of fresh, cool air. But heaps made exclusively of large particles not only present little surface area to microorganisms, they permit so much airflow that they are rapidly cooled. This is one reason that a wet firewood rick or a pile of damp wood ch

f One Gram of

ameter of Number

Particles per

e Sand 2.0

nd 1.00-0

d 0.50-0.2

0.25-0.1

and 0.10-00

-0.002 5,

f materials maintain a loose texture while soft, flexible stuff tends to partially fill in the spaces. However, even if the heap start

e the outer surfaces of a compost pile do not get hot, tend to completely dry out, and fail to decompose, turning the pile also rotates the unrotted skin to the core and then

hy material. This porous base tends to enhance the inflow of air from beneath the pile. One powerfu

arge-diameter plastic pipes with numerous quarter-inch holes drilled in them are spaced every three or four feet. Once the pile has been formed and begins to heat, the wooden posts are wiggled around and then l

th bacteria and fungi die off. The upwelling of heated air exiting the pile tends to rapidly dehydrate the compost heap. It usually is necessary to periodically add water to a hot work

neously be rehydrated. When I fork over a heap I take brief breaks and spray water over the new

diately slumps into a chilled, airless mass. Having large quantities of water pass through a pile can also leach out vital nutrients that feed organisms of decompos

sters, who can afford scientific guidance to optimize their activities, try to establish and maintain a laboratory-measured moisture content of 50 to 60 percent by weight. When building a pile, keep in mind that certain materials like fresh grass clippings and vegetab

to make a pile heat up that is less than three feet high and three feet in diameter. And a tiny pile like that one tends to heat only for a short time and then cool off rapidly. Larger piles tend to heat much faster and remain hot long enou

y have power equipment that simultaneously turns and sprays water, mechanically oxygenating and remoistening a massive windrow every few days. Even poorly-financed municipal composting systems have tractors with scoop loaders to tur

owing doesn't supply that many clippings; my own kitchen compost bucket is larger and fills faster than anyone else's I know of but still only amounts to a few gallons a week except during August when we're making jam, canning vege

ing thin layers of grass clippings, leaves, weeds, garbage, grass, weeds, garbage, and a sprinkling of soil, repeated until the heap is five feet tall. It can take months to build

r wet materials come available the can be covered with and mixed into this dry material. The wetter, greener items will rehydra

o becoming compost and much of the pile may have already dried out by the time it is fully formed. So th

, molasses, sunflower seeds, and oil aren't layered, they're thoroughly blended and then kneaded and worked togethe

of the compost that results. Piles composed primarily of materials with a high ratio of carbon to nitrogen do not get very hot or

enough with just grass clippings and kitchen garbage. Heaps made essentially of high C/N materials need significant additions of the most potent manures and/or highly concentra

ould be foolish. Even more wasteful of energy would be the composter's attempt to compute the ratio of carbon to nitrogen resul

ncin

roblem that illustrates how

6:1, how much chicken manure (C/N of 8:1) do I have

st at 25:1 would have about 4 pounds of nitrogen, so I need to add about 2.5 more pounds of N. Eight pounds of chicken manure contain 1 pound of N; 16 pounds have 2.

N was more or less right. If, after several turnings and reheatings, the material has not thoroughly decomposed, then the initial C/N was probably too high. The words "thoroughly decomposed" mean here that there are no rec

itrogen-deficient pile is to turn it, simultaneously blending in more nutrient-rich materials and probably a bit of water too. After a few pil

and probably smell of ammonia, indicating that valuable fixed nitrogen is escaping into the atmosphere. When proteins decompose their nitrogen content is normally released as ammonia gas. Most people have smelled small

but cannot survive the extreme high temperatures that a really hot pile can achieve. They also live only in soil. That is why it is very important to ensure that about 10 percent of a compost pile is soil and to coat the outside of a pile with a f

re it is promptly and completely altered into nitrates. A very hot pile leaking ammonia may contain too little soil, but more likely it is also so hot th

f at all possible, make compost in a sheltered location. Heavy, cold rains can chill and waterlog a pile. Composting under a roof will also keep hot sun from ba

compost pile made from autumn cleanup. This stack of leaves and frost-bitten garden plants may have to await the spring thaw, then to be mixed with potent spring grass clippings and other nitrogenous materials in order

aller or not as tall. Chapter Nine describes in great detail how Sir Albert Ho

izing Valu

certain that your compost may be the equal of or superior to almost any commercially made product and certainly will be better fertilizer than the h

il, whether for lawns, ornamental plantings, or vegetable gardens. Compared to the fertilizer you would have purchased in its place, an

lly participate in a natural cycle: the endless rotation of carbon from air to organic matter in the form of plants, to animals, and finally all of it back into

he growth response you'll get from compost depends on what went into the heap, on how much nitrate nitrogen was lost as ammonia during de

ach 80 degree for much of the frost-free season, organic matter rots really fast and a little compost of average quality makes a huge increase in plant growth. Where summer is cool and soil organic matter decomposes slowly, poorer grades of compost have little immediate effect, or worse, may temporarily interfere

. This aspect of gardening is so important and so widely misunderstood, especially by organic

ng th

making the corn patch get one foot taller. Making everything get as large as possible wouldn't result in maximum nutrition either. But just for fun, how

ed welder liked his liquor. Having more time than money and little respect for legal absurdities, he had constructed a small stainless steel pot still, fermented his own mash, and made a harsh, hangover-producing whi

them were four or five feet tall but those plants on the end housing the mash barrel were seven feet t

eet in diameter for individual plants. We can use well-finished, strong compost to increase the humus content of that soil, and supplement that with manure tea or liquid fertilizer to provide all the nutrients the plant could possibly use. We can allocate only one plant to that space and make sure absolute

small amounts of organic matter. Two or three hundred pounds (dry weight) of compost per thousand square feet per year will keep coarse-textured soils in wonderfu

in humus will crust over and puddle when it rains hard. These may need a little more comp

l properties of clay soils greatly benefit from additions of organic matter several times larger than what soils composed of

of compost, connect that to what they were made from and that to the kind of growing results one might get from them. I apologize that despite considerable researc

minate mixture of all sorts of urban organic waste: paper, kitchen garbage, leaves, chipped tree trimmings, commercial organic garbage like restaurant waste, cannery wastes, etc. Unfortunately, paper comprises the largest single ing

omposition-resistant forms like paper, and since the use of soil in the compost heap is essential to prevent nitrate loss, municipal composts tend to be low in nitrogen and high in carbon. By comparison, the poorest home garden compost I could find test results for was about equal to the best municipal compost. The best garden sample ("B") is pretty fine stuff. I could not di

of Variou

N% P% K

ings & paper 1.

fuse 0.97 0.

efuse 0.91 0.2

refuse 0.57 0

st "A" 1.40

st "B" 3.50

cken manure compost. The most potent I've ever purchased is inexpensively sold in one-cubic-foot plastic sacks stacked up in front of my local supermarket every spring. The sacks are labeled 4-3-2.

ificent garden. Most certainly a similar amount of the high analysis Garden "B" compost would do about the same job. Would three times as much less potent compost from Garden "A" or fi

specially important. Even if the C/N is still high soil animals will continue the job of decomposition much as happens on the forest floor. Eventually their excre

f only slight improvements are made in their soil. The same is true for most herbs. Difficulties with ornamentals or herbs are usually caused by attempting to grow a species t

them demand very high levels of available nutrients as well as soft, friable soil containing reasonable levels of organic matter. So it is extremely impo

call great compost like this, "stable humus," because it is slow to decompose. Its presence in soil steadily feeds a healthy ecology of microorganisms important to plant health, and whose activity accelerates release of plant nutrients from undecompos

comes other plant nutrients. This accelerated nitrification continues until the remaining nitrogen balances with the remaining carbon at a ratio of about 12:1. Then the soil returns to equilibrium. The lower the C/N the more rapid

match any food supply. But to construct their bodies these microorganisms need the same nutrients that plants need to grow-nitrogen, potassium, phosphorus, calcium, magnesium, etc. There are never enough of these nutrients in high C/

quently, germination failures may occur. When I was in the seed business I'd get a few complaints every year from irate gardeners demanding to know why every seed packet they sowed failed to come up well. There were two usual causes. Either before sowing all the seeds were exposed to temperatur

not expect it to nitrify humus while it was also being required to digest organic matter. That's one reason he thought composting was such a valua

eased back into the soil. How long the soil remains inhospitable to plant growth and seed germination depends on soil temperature, the amount of the material and how high its C/N i

making. One governmental composting operation that does succeed in selling everything they can produce is Lane County, Oregon. Their yard waste co

ting and comprise no more than 20 percent of the total undecayed mass by weight. Although no nutrient analysis has been done by the county other than testing for pH (around 7.0) and, because of the use of weed and feed fe

. They reasonably offer to deliver their compost for a small fee if at least one y

ost everything you have available and use all you wish to make. If tilling your compost into soil seems to slow the growth of pl

the fall for next year's planting, by which time it will have become stable humus, or read further. The second half of this book contains numerous hin