‘Biofertilizer’ is a substance which contains living microorganism which, when applied to seed, plant surfaces, or soil, colonizes the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant. Biofertilizers are not fertilizers. Fertilizers directly increase soil fertility by adding nutrients. It add nutrients through the natural processes of fixing atmospheric nitrogen, solubilizing phosphorus, and stimulating plant growth through the synthesis of growth promoting substances. They can be grouped in different ways based on their nature and function.

1. Nintrogen fixing biofertilizers, Free-living Azotobacter, Symbiotic Rhizobium, Associative Symbiotic Azospirillum
2. Phosprous solubilizing biofertilizers, Bacteria Fungi
3. Phosprous mobilizing biofertilizers, Arbuscular mycorrhizae, Ecto mycorrhizae, Orchid mycorrhizea
4. Biofertilizers for micro nutrients, Silicate and Zinc solubilizers
5. Plant growth promoting rhizobacteria, Pseudomonas

ADVANTAGES OF BIOFERTILIZERS

These are cost effective relative to chemical fertilizers. These are environment friendly not only prevent damaging the natural resource but help to clean the nature from precipitated chemical fertilizers and thus can provide better nourishment to plants.

• Beneficial microbes are required right from the stage of seed development to plant.
• Helps to build immunity against abiotic stress
• Nitrogen fixation in soil to make it available to plants
• Solubilization of unavailable forms of nutrients to make them plant-available