Composting is the process of controlled decomposition of organic solid matter (e.g. organic wastes such as plant residues, kitchen wastes, excreta, etc.) into CO2 and heat in the presence moisture. Composting is carried out by aerobic (requiring free or molecular oxygen found in air) microorganisms, mainly bacteria and funghi. Composting is simple and practiced by individuals in their homes, farmers on their land, and industrially by industries and cities.