ABSTRACT
Soil organic matter is derived from the soil biomass, and strictly speaking it consists of both living and dead organic matter. It is the most important fraction in soils and has attracted considerable attention since the early days of agriculture because of its pronounced effect on the physical, chemical, and biological condition of soils (Russell and Russell, 1950; Tan, 2000). The growth and yield of crops have always been noted to be better when plants are grown in soils rich in organic matter. Lack of scientific data in the past is perhaps one of the reasons for the presence of some reservations as to its beneficial effect on soils and plants (Stevenson, 1994).
