Role of phosphorus solubilizing cultures in sustainable agriculture

Phosphorus (P) is a key elementrequired for the growth and metabolism in crop plants. Unlike nitrogen, there is no atmospheric source for phosphorus (P) which can be made biologically available. In the soil, Phosphorus is present in varying forms, with lowest availability in Oxisols. Plants acquire phosphorus from the soil as phosphate anion, which is least mobile element in plants and soil, in comparison to other macronutrients. Most of the soil phosphorus is in unavailable form and hardly about 1 to 2% of it gets incorporated in above ground parts of the plants. It precipitates in soil as orthophosphate or is adsorbed by Fe and Al oxides through legend exchange. Root development, stalk, stem strength, flower, seed formation, crop maturity, production, N-fixation in legumes, crop quality and resistance to plant diseases are the attributes associated with phosphorus nutrition. In this respect, apart from chemical fertilizers as a source of phosphorus, mic robial inoculants are becoming most popular as those are cost effective, ecofriendly, and renewable sources of plant nutrients