Biofertilizer is the biologically active products or microbial inoculants of bacteria, algae and fungi, which may help biological nitrogen fixation for the benefit of plants.
Biofertilzers also include organic fertilizers (manures, etc.), which are rendered in an available form due to the interaction of microorganisms or due to the interaction of micro-organisms or due to their association with plants.
Biofertilzers thus include (i) symbiotic nitrogen fixers e.g. Rhizobium spp.; (ii) asymbiotic free nitrogen fixer e.g. Azotobacter, Azospirillum, etc. (iii) algae biofertilisers e.g. blue green algae or BGA in association with Azolla; (iv) phosphate solubilising bacteria; (v) mycorrhizae; (vi) organic fertilizers.
The need for the use of biofertilzers has arisen, primarily of two reasons. First, because increase in the use of fertilizers leads to increased usage of chemical fertilizer leads to damage in soil texture and raises other environmental problems.
Therefore, the use of biofertilzers is both economical and environments friendly. The pragmatic approach will be to develop the integrated nutrient supply system involving a combination of the use of chemical fertilizers and biofertilzers.