Microbial Inoculants for Sustainable Legume Production

Abstract

The role of legumes in improving soil fertility is well known and hence is being introduced to newer areas to enrich the soil with plant nutrients, especially nitrogen. Since legumes are an important source of dietary protein, their production is linked to food security. Furthermore, identification of insecticidal components in legume extract and fiber in pea offers other interesting opportunities to legume growers. All these properties together have generated greater interest in growing legumes worldwide. Therefore, there is a need to enhance the productivity of legumes. To optimize the productivity of legumes, synthetic chemicals are used which are not only costly but also adversely affect the environment when used inadvertently. To circumvent both cost and environmental hazards and to increase productivity of legumes, rhizobial inoculation either alone or in combination with other plant growth promoting microorganisms (PGPMs), such as phosphate-solubilizing microbes and mycorrhizal fungi, have been practiced over the years. In a number of studies, inoculations of legumes with various PGPMs have shown enhanced production. Inoculation with PGPMs has been found to improve uptake of nutrients and protection against pests, pathogens and induce systemic acquired resistance to legumes. It may, however, be important to identify the combination of PGPMs that work synergistically to enhance productivity of various legume crops. In this review, the published literature on the use of PGPMs in legume cultivation has been compiled so as to identify microbial inoculants for sustainable production of legumes.