Microbial inoculants: Identification, characterization, and applications in the field

Abstract

Microorganisms play a very important role in recycling of nutrients and organic compounds. They are also involved in improving structure and fertility of soils and managing plant health and ecosystem functioning. Microbes show interactions with plants, animals, and soils, working sometimes as pathogens while sometimes for mutual benefits. Currently very advanced biochemical, microbial, and molecular tools and techniques have been developed which provide accurate, rapid methods for determining microbial diversity in any ecosystem. About 99 % of the microbes in the environment are non-culturable; therefore, much more efforts are required to make them culturable and then identifiable. Microorganisms are potentially useful for accelerating plant growth and increasing crop yields. It has been observed that significant numbers of microbial species, usually associated with the plant rhizosphere, are able to exert a beneficial effect upon the growth of plant. They possess inevitable role in nutrient supply (N2 fixation, P solubilization, IAA production, etc.) or biocontrol mechanism. In field, the beneficial effects of microbial inoculants has been proved by various researchers. In this chapter, various approaches employed in identification and characterization of culturable microbes, their various plant growth-promoting features, and role as bioinoculants have been given.