Composting is an easy, environmentally beneficial way to turn yard and kitchen wastes into a dark, crumbly, sweet-smelling soil amendment that will build your soil, increase garden production and do wonders for your landscaping.
Composting recycles organic household and yard waste and manures into an extremely useful humus-like, soil end-product called compost. Ultimately this permits the return of needed organic matter and nutrients into the foodchain.
Composting is widely believed to speed up the natural process of decomposition appreciably as a result of the raised temperatures that often accompany it. The elevated heat results from exothermic processes, and the heat in turn reduces the generational time of microorganisms and thereby speeds the energy and nutrient exchanges taking place. It is a very popular misnomer that composting is a "controlled" process; if the right environmental circumstances are present the process virtually runs itself. Hence a popular expression, "compost happens".
Decomposition similar to composting occurs throughout nature in the absence of all the conditions that modern composters talk about; however, the process can be slow. For example, in the forest bark, wood and leaves break down into humus over 3-7 years. In restricted environments, for example, vegetables in a plastic trash container, decomposition with a lack of air encourages growth of anaerobic microbes, which produce disagreeable odors. Another form of degradation practiced deliberately in absence of oxygen is called anaerobic digestion- an increasingly popular companion to composting as it enables capture of residual energy in the form of biogas, whereas composting releases the majority of bound carbon-energy as excess heat (which helps sanitize the material) as well as copious amounts of biogenic CO2 to the atmosphere.