At present, one of the new challenges is to obtain more and more agricultural food production from shrinking per capita arable land. Biofertilizers have important and long term environmental implications, negating the adverse effects of chemicals. At the farm level, the gains from increased usage of technology can spill over to other farms and sectors through lesser water pollution than chemical fertilizers and to an extent even organic manures can be created. The gains from the new technology coming through the arrest of soil damage may not be perceived over a short span of time, unlike chemical fertilizers, which yield quick returns. Liquid bio-fertilizers are special liquid formulations containing not only the desired microorganisms and their nutrients but also special cell protectants or chemicals that promote formation of resting spores or cysts for longer shelf life and tolerance to adverse conditions.
Moreover, Biofertilizers, more commonly known as microbial inoculants, are artificially multiplied cultures of certain soil organisms that can improve soil fertility and crop productivity.
Although the benefits of legumes in improving soil fertility was known since ancient times and their role in biological N-fixation was discovered more than 100 years ago, commercial exploitation of such biological processes is of most interest and practice. Latent cells of efficient strains of nitrogen fixing, phosphate solubilizing or cellulolytic micro-organisms are used for application to seed, soil or composting areas with the objective to increase the number of such micro-organisms and accelerate those microbial processes which augment the availability of nutrients that can be easily assimilated by plants.
Not all Plant Growth Regulators (PGR’s) can be considered biofertilizers. There are bacteria that promote plant growth by control of deleterious organisms as bio-pesticides, but not biofertilizers. Similarly bacteria can enhance plant growth by producing phytohormones and are regarded as bio enhancers, not biofertilizers. Biofertilizers play a very significant role in improving soil fertility by fixing atmospheric N, both, in association with plant roots and without it, solubilise insoluble soil phosphates and produces plant growth substances in the soil. Biofertilizers are the preparations containing cells of microorganisms which may be N fixers, P solubilizers, S- oxidisers or organic matter decomposers. In short, they are called as bio inoculants which on supply to plants improve their growth and yield. In present times a need has arisen for organic fertilizers including biofertilizers to minimise our dependence on fertilizer N. The experiments conducted on biofertilizers revealed that legumes such as beans, soybean, chickpea, pigeon pea can fix 50-500 kg atmospheric N/hectare under ideal conditions of environment. Therefore, Bio-fertilizers offer a safe option to utilize renewable inputs to improve the fertility of land using biological wastes with those beneficial micro-organisms which impart organic nutrients to the farm produces.
Biofertilizers have emerged as potential environment friendly inputs that are supplemented for proper plant growth. They hold vast potential in meeting plant nutrient requirements while minimizing the use of chemical fertilizers. These, bio-inputs or bio inoculants, which on supply to plants improve their growth and yield, are the products containing living cells of different types of microorganisms which have an ability to mobilize nutritionally important elements from non-usable form through biological stress. In modern agriculture, due to heavy usage of chemical fertilizers and harmful pesticides on the crops, sustainability of the agriculture systems collapsed, cost of cultivation soared at a high rate, income of farmers stagnated and food security and safety became a daunting challenge. Indiscriminate and imbalanced use of chemical fertilizers, especially urea, along with chemical pesticides and unavailability of organic manures has led to considerable reduction in soil health.
