Role of bioinoculants as plant growth-promoting microbes for sustainable agriculture

Abstract

The green revolution bought amazing consequences in food grain production but with insufficient concern for agriculture and environmental sustainability. The efficient biofertilizers are gaining importance in sustaining agriculture. Various complementing combinations of microbial inoculants for management of major nutrients are necessary for agriculture sustainability. In such case, microorganisms are useful for biomineralization of bound soil and make nutrients available to their host and/or its surroundings. Nitrogen and phosphorus are major plant nutrients which occupy a key place in the balanced use of fertilizer. Leguminous crop fixes the atmospheric nitrogen by Rhizobium which requires optimum level of phosphorus in plant tissue. Mineral solubilizers play an important role in seedling setting because more of the tropical soils are phosphate fixing and make it unavailable to the plants. Phosphate-solubilizing microorganisms (PSMs) that solubilize bound form of phosphorus and AM fungi act as uptaker of phosphorus and make it available to the host plants. Microorganisms facilitate plant mineral nutrition by changing the amounts, concentrations and properties of minerals available to plants. Because of the various challenges faced in screening, formulation and application, PGPB have yet to fulfil their promise and potential as commercial inoculants. This chapter focuses on some important information regarding the various types of biofertilizing potential of some important group of microbes, their formulations, their application for the development of sustainable technology, their scope of improvement by promising new technique and commercially available biofertilizer and its application in India.