By piling kitchen scraps and garden debris in a bin or heap, gardeners create an ideal habitat for decay organisms. These microorganisms break organic material down to form humus. In addition, the heat inside the pile from all the biologic activity will kill off many disease organisms and unwanted seeds. Compost piles benefit from the addition of manures (for their high nitrogen count and the beneficial bacteria they harbor), occasional watering (so that it is moist not wet), and frequent turning (for aeration).
The biological , process of organic materials such as leaves, grass clippings, brush, and food waste into a soil amendment.