A compost heap is a collection of organic material which is kept in a state of aerobic decomposition, encouraging the material to break down into an extremely rich soil product which can be used in gardening. Many people in rural areas have compost heaps at home, and in some areas industrial compost heaps and municipal compost collection is available, encouraging citizens of cities and large businesses to dispose of greenwaste sustainably, rather than in landfills. In some regions, composting is actively encouraged by regional governments.
The concept of composting is quite ancient. Essentially, the process involves encouraging materials like food waste and cuttings of grasses and branches to rapidly decompose, returning the nutrients bound in these materials to the earth in the form of soil. Manure is also often included in compost heaps, furthering rapid breakdown. When a compost heap is well maintained and well balanced, it produces surprisingly minimal odor, and it can take less than three months for materials to break down, making composting a very efficient method for handling organic material.
There are several different forms of composting. Active or hot composting involves keeping a compost heap extremely well maintained, so that aerobic bacteria will flourish, breaking down the material in the compost heap quickly. This is known as hot composting because the bacteria generate heat as they break materials down, and such compost heaps sometimes actively steam. Biodegradeable plastics like containers made from corn can be broken down in hot compost piles. Aerated composting is a step down, involving routinely raking the material to keep fresh air circulating through the pile, while passive composting such as that in many small gardens doesn't reach high temperatures, so it takes longer for the contents of the compost heap to break down.
A wide variety of things can be added to a compost heap, including food scraps, wood chips, sawdust, dung, grass clippings, leaves, paper, light cardboard, coffee grounds, and so forth. Some people also inoculate compost heaps with bacteria to hasten the breakdown process, and in passive composting, worms may be added to keep the compost aerated and to facilitate decomposition. Once all of the material has broken down into a dark brown crumbly substance, it is ready to use; some people divide their compost heaps into several parts to generate a steady supply of fresh compost for their gardens.
Composting at home is not that challenging. You will require some space, either indoors or outdoors, and if you decide to compost in containers, the containers need to be very well drained, as compost likes to be fairly dry. One way to compost conveniently is to build extremely sturdy wire cages which are elevated, allowing finished compost to fall through the bottom for easy collection. As long as you aerate the compost regularly with a rake shovel, the odor should stay fairly minimal; you can also amend the compost with materials like sawdust to help it dry out.