Composting Part 1
What is Compost?
Compost is a dark, crumbly mixture of decomposed organic matter, such as grass clippings, leaves, twigs, and branches.
How Does Composting Work?
Even the first-
Materials
Anything that was once alive will naturally decompose. However, some organic wastes should not be composted at home.
DO compost these items: grass clippings, leaves, plant stalks, hedge trimmings, old potting soil, twigs, annual weeds without seed heads, vegetable scraps, coffee filters, and tea bags.
Do NOT compost these items: diseased plants, weeds with seed heads, invasive weeds such a quack grass and morning glory, pet feces, dead animals, bread and grains, meat or fish parts, dairy products, grease, cooking oil, or oily foods.
Making It Work
To prepare compost, organic material, microorganisms, air, water, and a small amount of nitrogen are needed.
Organic material is leaves, grass clippings, etc. that you are trying to decompose. Microorganisms are small forms of plant and animal life, which break down the organic material. A small amount of garden soil or manure provides sufficient microorganisms.
The nitrogen, air, and water provide a favorable environment for the microorganisms to make the compost. A small amount of nitrogen fertilizer can add sufficient nitrogen to the compost. You can purchase nitrogen fertilizers at many hardware stores, feed stores, or nurseries.
Air is the only part which cannot be added in excess. Too much nitrogen can kill microbes; too much water causes insufficient air in the pile.
Biology
Bacteria are the first to break down plant tissue and are the most numerous and effective compost makers in your compost pile. Fungi and protozoans soon join the bacteria and, somewhat later in the cycle, centipedes, millipedes, beetles, and worms complete the composting process.
Source: United States Department of Agriculture