ABSTRACT
Plants are the generators or the primary source of organic matter while animals are the transformers- secondary source of organic matter. In agriculture, plants add 10-30 percent of organic matter through their roots stubbles and leaf fall and exudations. The excreta of livestock, the organic wastes of urban and rural residential areas include the garbage and sewage and sludge. Soil organic matter binds individual soil particles into aggregates that are responsible for good structure and porosity distribution which allow aeration, root penetration and movement and retention of water. Polysaccharides are formed by the action of microbes which act as cementing agents which improves the aggregate stability. Carbon-nitrogen ratio is significant in management of crop residue and green manure. When crop residues with wider C: N is used the sowing of crop should be taken after 3 weeks of incorporation of crop residues.
