Bio fertilizer is one of the best modern tools for agriculture, containing those microorganisms that can play a great role in the improvement of soil fertility and crop productivity. They are live or latent cells of efficient strains or biologically active products or microbial inoculants of bacteria, algae, and fungi which help crops to the uptake of nutrients by their interactions in the rhizosphere when applied to seed, soil and plant surface. They are helpful in a conversion of complex nutrients into simple nutrients for the availability of the plants.

Azotobacter, Azospirillum, Rhizobium, phosphorus, and potassium solubilizing microorganisms and mycorrhizae are some of the plant growth promoting rhizobacteria that add nutrients through the natural processes of fixing atmospheric nitrogen, solubilization of phosphorus, potash and stimulating plant growth through the synthesis of growth promoting substances.

Now, a current challenge of the new millennium 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 chemical fertilizers. Use of biofertilizers is one of the important components of integrated nutrient management, as they are a cost-effective, environment-friendly and renewable source of plant nutrients to supplement the chemical fertilizers for sustainable agriculture.