The reason of our thus treating composts of various soils and substances,
is not only to dulcify, sweeten, and free them from the noxious qualities they otherwise retain. . . .
[Before composting, they are] apter to ingender vermin, weeds, and fungous . . . than to produce wholsome [sic] plants, fruits and roots, fit for the table.
—J. evelyn, 17th Century
Decomposition of organic materials takes place
it may cause extreme drying and triggers a die-off of all
naturally in forests and fields all around us. Composting
but the most heat-resistant organisms. At temperatures
is the art and science of combining available organic
below 110°F, the more prolific mesophilic organisms take
wastes so that they decompose to form a uniform and
over and the rate of composting again slows down, espe-
stable finished product. Composts are excellent organic
cially as it drops toward ambient temperatures, a process
amendments for soils. Composting reduces bulk, sta-
known as “curing.” The composting process is slowed by
bilizes soluble nutrients, and hastens the formation of
anything that inhibits good aeration or the maintenance
humus. Most organic materials, such as manures, crop
of high enough temperatures and sufficient moisture.
residues, grass clippings, leaves, sawdust, and many
Composting farm wastes and organic residues
kitchen wastes, can be composted.
from off the farm has become a widespread practice.
The microorganisms that do much of the work of
rapid composting perform well at elevated temperatures
tYPes of coMPostInG
with plenty of oxygen and moisture. These compost-
Some people talk about “low-temperature” com-
adapted organisms cover the entire range of warm,
posting—including “sheet,” worm (vermicomposting),
or mesophilic (up to 110°F), and hot, or thermophilic
and small-pile composting—and “high-temperature”
(from 110ůp to 130°F and even higher), conditions.
composting. We like to use the term “composting”
Temperatures above 160°F can develop in compost piles,
only when talking about the rapid decomposition that
helping kill off weed seeds and disease organisms, but
takes place at high temperatures.
this overheating usually slows down the process, since
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Building SoilS for Better CropS: SuStainaBle Soil ManageMent