Microbial biofertilizer: Types, applications, and current challenges for sustainable agricultural production

Abstract With ever-increasing population of the world, which has now reached 7.75 billion, it has become a major challenge for world to meet the sustainable development goal (SDG) of zero hunger via meeting demand for food, feed, and other agricultural products especially in developing countries. Therefore, improving and sustaining agricultural crops yield without posing negative impact on environment should be the ultimate goal to meet food and nutritional requirement around the world. Application of chemical fertilizers although has increased the crop productivity but simultaneously has posed serious threat to human and environmental health. Therefore, biofertilizers from microorganisms have potential to replace these chemical fertilizers in sustaining agricultural productivity and maintaining environmental health. Moreover biofertilizers are easy to use and less expensive than chemical fertilizers. Biofertilizers includes one or more beneficial microbes that facilitate better nutrient uptake, greater production of growth hormone and beneficial phytochemicals in crops leading to higher quantity as well quality crop production. Nitrogen-fixing microbes, phosphate-solubilizing bacteria (PSB), sulfur-solubilizing bacteria (SSB), potassium-solubilizing bacteria (KSB), and vesicular-arbuscular mycorrhiza (VAM) etc. are already being utilized in combination for making biofertilizers formulations for enhancing crop production but on small scale. Thus, large scale exploitation of agriculturally important microbes for sustaining agricultural productivity is the need of the hour. This chapter highlights the types, quality control measures, inoculation techniques of microbial biofertilizers; their role in sustaining agricultural productionand challenges as well as ways forward to promote the use of biofertilizers in order to achieve sustainable agricultural production to meet out the SDG of zero hunger.