Horticulture Principles and Practices

the temperate zone, however, sunlight is required to keep the heap warm. It is wise to locate
the heap so that the house is not downwind from it; in the case of poor decomposition, the
foul odors will not blow into the house with the wind. The site should be well draining.
Container Design
Containers or retaining walls may be constructed out of a wide variety of materials
including blocks, plastic, wood, and even baled straw (Figure 22–2). On a well-drained
location, the ground may be used as the bottom wall of the container (Figure 22–3). The
advantage of using bare earth for the bottom of the container is that natural decomposers
in the soil have the opportunity to act on the material in the pile. Wooden and wire bins
are also used (Figure 22–4). Since wood is biodegradable, a wood preserver or latex paint
coating reduces the danger of its decomposition. Wire bins are well ventilated and as
such lose heat rapidly. Barrels, drums, tumblers, and plastic bins may be used as
containers for composting (Figure 22–5).
Pit composting is simply burying the composting materials in a pit dug in the soil
until they decompose (Figure 22–6). When ready, which may be up to a year, the
FIGURE 22-2
a concrete pit.
Composting in
Compost pile
Retaining wall
Insulation (thick layer of
straw, leaves, burlap, etc.)
Soil
Manure
Activators
Plant material (leaves,
clippings, etc.)
Drainage pipe (fitted under the
bottom of the bin from the center)
FIGURE 22-3 Composting
directly on the ground.
Grass is cleared; the shallow
bottom is lined with gravel
or other coarse material
before layers of compost
material are arranged
Ventilation
(for accelerated
decomposition)
Compost heap is
covered with an
insulation layer
666 Chapter 22 Organic Farming