The use of fertilizer on arable land has increased 60% during the past 50 years. The challenge related to the availability of fertilizers by 2050 is crucial since fertilizers ultimately play a key role in feeding the increasing population. Increased use of fertilizers and stimulants has led to soil quality and environmental degradation, biodiversity loss eutrophication, and heavy metal pollution. Moreover, the overuse of Nitrogen containing chemical fertilizers like urea produces ammonia emanation and this contributes to acid rain, groundwater contamination and ozone depletion by the release of nitrous oxide by the denitrification process.
A better alternative to these chemicals is biofertilizers, which can replace chemical fertilizers to increase crop production. Biofertilizers are microbial inoculants that have cells of microorganisms, and through this high soil productivity is enhanced. These fertilizers have the role of stimulating the plants’ growth via synthesis. In principle, biofertilizers are less expensive and are more environmentally friendly than chemical fertilizers.
Biofertilizers are heterogeneous in nature comprising bacteria, fungi and actinomycetes that survive in and around the root rhizosphere. They enhance the plant growth and yield either directly or indirectly. They involve in the solubilization or mobilization of essential nutrients (phosphorous, potash, zinc, sulphur, and iron) or fixing atmospheric nitrogen for the uptake of plants. They are also known to produce various plant growth promoting hormones like indole acetic acid, gibberellic acid, cytokinins, and ethylene. They also indirectly reduce the deleterious effect of phytopathogens.