ABSTRACT
By understanding the fate of fertilizers, measures for increasing their efficiency can be suggested and adopted. When fertilizers react with soils, the compounds produced are by and large similar to the ones which are present in soils and which are produced by the breakdown of minerals and organic matter. Nitrogen occurs in soil in both cationic and anionic forms, the greater parts occurs in organic forms. Mineralization of organic N involves two reactions, aminisation and ammonification, which occur through the activity of heterotrophic micro-organisms. Organic and inorganic forms of phosphorus occur in soils and both the forms are important to plants as source of phosphorus. The relative amounts of phosphorus in organic and inorganic forms vary greatly from soil to soil. Potassium in soil occurs in four phases namely soil solution phase, exchangeable phase, non-exchangeable phase and mineral phase.
