The goal of composting is to take the organic materials through the initial stages of decomposition so that they will not be a source of disease, pests or weeds, and will more rapidly provide humus for the soil, support an array of beneficial organisms and release essential nutrients for plant growth. Aerobic decomposition is a heat generating process that requires oxygen and it usually takes place in a pile above ground. Anaerobic decomposition does not require oxygen and does not produce heat. It is usually done in a pit below the soil surface. Aerobic decomposition is a more rapid process and relatively odor free.
Anaerobic decomposition is slower and can generate strong odors.
Both types of decomposition can result in excellent compost. Aerobic composting is the more common process when composting is done in the back yard, but anaerobic is also common and both are used in commercial programs. Few things are as good for the garden or field as an application of a generous dose of organic matter. Grass clippings, tree leaves, kitchen scraps, weeds, old hay, manures, wood shavings, and plants from the vegetable garden are all good examples of compostable materials. Fats and bones from the kitchen should not be added to the pile, plants with disease-causing pathogens that would not be destroyed in the decomposition process should not be added, and cat manure should be kept out of the compost pile.