Screening of Efficient Phosphate Solubilizing Microorganisms from Rhizosphere of Some Export Agricultural Crops

Abstract

Nutrient deficiency, chemical fertilizer application and soil deterioration is a well-known cyclic occurrence associated with agriculture in which successive cycles lead to more and more deterioration of soil. With the advancement of technology, sustainable and environmentally friendly solutions are sought to address such problems. Development of biofertilizers to supplement soil with nutrients eases the demand on chemical fertilizers and its negative impacts on the environment. Phosphorus (P) is one of the major plant nutrients. Its deficiency limits the plant growth and development in almost all agricultural soils. Due its high reactivity, applied P readily combines with soil minerals forming insoluble phosphates, lowering its availability to plants. As such, development of an economical and environmentally friendly alternative for successful soil P management is a major concern in crop production and phosphate solubilizing microorganisms (PSM) attracted attention in this regard (Rodriguez and Fraga, 1999). Export agricultural crops (EAC) are important contributors to the Gross National Product. Although Eppawala rock phosphate (ERP) is applied to EACs concerning the perennial nature of the plant, it has been shown that phosphate availability of ERP for EACs can be increased using PSMs (Mala et al, 2010). Hence, the main objective of this study is to develop a phosphate biofertilizer for EACs using suitable phosphate solubilizing microorganisms.