Rhizobial Inoculants for Sustainable Agriculture: Prospects and Applications

Abstract

Due to continuous growth of world population, there is dire need of serious efforts and innovative approaches to meet food demands through sustainable production practices, improvement in supply chain, and control of food wastage. All these efforts should ensure the access to nutritious food to all suffering from hunger and malnutrition. Due to intensive crop cultivation and use of synthetic fertilizers, soil health is seriously deteriorating. However, soil fertility can be improved by incorporating legumes in the cropping system and/or use of rhizobial inoculants, which not only increase nitrogen fixation but also improve soil fertility and crop production through several other attributes such as phosphate solubilization, siderophores production, phytohormones production, enzymes synthesis, and exopolysaccharides production. Moreover, these bacteria can be helpful for improvement in crop production on marginal lands due to their tolerance against various biotic and abiotic stresses. All these characteristics make rhizobia equally important for non-legumes as for legumes. The use of rhizobial inoculants can ensure improvement in crop productivity and environment sustainability by enhancing soil fertility and reduction in use of synthetic chemical fertilizers. Present review focuses on important plant growth-promoting mechanisms of rhizobia and the use of these rhizobia for sustainable crop production through improvement in crop nutrition, physiology, productivity, and stress tolerance of crop plants. The potential of the synergistic use of rhizobia with other soil microorganisms for sustainable agriculture has also been elucidated with examples, followed by their future prospects.