Phosphate solubilising microorganisms: role in phosphorus nutrition of crop plants-A review

Phosphorus is the least mobile nutrient element in plant and soil compared to other essential macronutrients. Root development, stalk, stem strength, flower, seed formation, crop maturity, N-fixation in legumes and crop quality are the attributes associated with phosphorus (P) nutrition. Phosphorus solubilizing microorganisms play role in P nutrition by enhancing its availability to plants through release from inorganic and organic soil P pools by solubilization and mineralization. Principal mechanism in soil for P solubilization is lowering of soil pH by microbial production of organic acids and mineralization of organic P by acid phosphatases. Use of phosphorus solubilizing microorganisms alone or in combination with other beneficial bacteria and mycorrhiza as inoculants increase prospects of direct application of rock phosphate (RP) in P uptake and crop production.