Creating a compost pile as a classroom project will demonstrate
to students that natural materials can be recycled.
A location for the project, organic waste materials, a garden
pitchfork, soil, water. (Lime, manure, nitrogenous fertilizer,
materials to construct an enclosure, a ½inch mesh screen,
and a soil thermometer are optional.) Volunteers must be available
to construct and maintain the compost pile.
Compost is an inexpensive and effective soil conditioner that
recycles organic waste materials. Nutrients in plant material
are returned to the soil through the breakdown of organic material
by the action of microscopic fungi and aerobic bacteria. Organic
wastes are decomposed, and the result is a material useful as
a natural fertilizer.
In Japan, Europe, and recently in the United
States, municipalities have established large-scale solid municipal
composting facilities. The volume of organic material composted
is diverted from other disposal facilities. Municipalities have
found that composting leaves collected in the fall can save disposal
When properly managed, a compost pile will
not produce odors or attract pests. The finished product can be
ready for use as a garden mulch in as little as six weeks with
proper management. Compost has proven valuable for use in land
reclamation efforts where erosion or earth moving activities have
disturbed the topsoil.
1. Find a suitable outdoor site to locate the compost pile. The pile should be exposed to rainfall, but may work best in a shaded location. Proximity to a water source is suggested.
A good time to start a compost pile is whenever
organic materials are available. The fall of the year is quite
suitable, since composting can serve as an alternative to the
burning or landfilling of leaves. Tree-trimmings, grass clippings,
garden refuse, kitchen and lunchroom food wastes, sawdust, manure,
wood ashes, hay and straw are among the organic wastes suitable
for composting. Meat and dairy products should be avoided.
2. Develop a plan of operation that outlines
the procedures for conducting the composting project. Present
the plan to the school principal. Permission and support from
administrative and maintenance personnel must be obtained before
initiation of the composting project.
3. An easy to manage compost pile can be enclosed on three sides by utilizing wooden pallets, used concrete block, fencing, snow-fencing, or hay bales. The fourth side should be accessible to permit turning the pile. A 4'x4'x4' enclosure can yield a ton of compost.
A compost pile can be constructed without
an enclosure. A shallow pit may be excavated and the organic material
simply piled. The excavated soil will be added to the pile.
4. Begin the compost pile with a layer of branches or cornstalks to help promote ventilation and drainage. The compost pile is then built with successive eight-inch layers consisting of a six-inch layer of organic material moistened with water and covered with two inches of soil, lime, manure or nitrogenous fertilizer. Shredding the organic materials will accelerate the decomposition process.
The eight-inch layers are repeated until the
pile is four feet high. Each layer should be moistened, but not
soaked. Materials in the compost pile should always remain as
damp as a squeezed sponge. A depression created at the top center
of the pile will collect precipitation. (Layering of materials
is not essential to the process.)
5. The compost pile is now ready for decomposition.
During this phase the temperature within the pile may reach 175o F.
The heat is effective in eliminating most disease organisms, insects,
and weed seeds. Diseased or infested materials should not be added
to the compost pile.
The pile should be turned over and mixed every
few weeks to move outer materials to the center. Less frequent
turning will delay decomposition. A steady decrease in the temperature
at the center of the pile will signal the end of the fermentation
process. When the compost is finished, it will have a dark color
and a crumbly soil-like texture.
6. Maintain a record of the composting process.
Enter the date of compost pile construction, the organic materials
added to the pile, the days the compost pile is turned, the date
the compost is ready, how the compost is used and other observations.
7. A soil thermometer can be used to monitor
the temperature of the pile. Create a compost pile temperature
chart plotting thermometer readings over the term of the project.
8. The finished compost may be sifted through
a ½" mesh screen with rejected particles returned
to the compost pile, or the compost may be added directly to garden
soil. Applied as a mulch or top dressing around plants shrubs
and trees, the compost will provide soil nutrients, retain moisture,
and inhibit weed growth. Look for uses for compost around the
school grounds. Consider marketing sifted compost as a fund-raising
9. Prepare a report that will describe the
composting project. Refer to the project log (Item 6) for
key information. Present the report to the school principal. Consider
publicizing the project in the school and community newspaper.