Compost is a dark crumbly humus derived from the breakdown of organic waste. It is used to add nutrients to soil, improve soil texture, and increase the ability of soil to hold air and water. It will not harm plant roots like commercial fertilizers can.
A properly constructed compost pile will generate heat when microorganisms feed on the organic waste. Heat accelerates decomposition and kills harmful bacteria. To build a compost pile, you should start with a 50/50 mix by weight of greens and browns. Green materials, such as fresh grass clippings, garden refuse, coffee grounds, feathers, and food scraps, are high in nitrogen, while brown materials, such as autumn leaves, paper, peat moss, sawdust, cornstalks, straw, and dried grass, are high in carbon. You want a pile that is large enough to prevent rapid loss of heat and moisture, yet small enough to allow good air circulation. Storing the materials in a container during the decomposition process helps to retain heat, control moisture, and keep out rodents.