Biofertilizers

• The term “bio” means living; so bio-fertilizers refer to living, microbial inoculants that are added to the soil.
• These bio-fertilizers are products consisting of selected and beneficial microorganisms, which are known to improve plant growth through supply of plant nutrients.

Types of biofertilizers

1. Nitrogen fixers

a. Symbiotic Rhizobium

b. Non-symbiotic

I. Aerobic: Azotobacter

ii. Anaerobic: Clostridium, Closteridium

2. Non nitrogen fixing bacteria

a. Aerobic: Ammonifiers

b. Anaerobic: Denitrifiers

3. Phosphate solubilizing micro-organisms

4. Cellulolytic and lignolytic micro-organisms

5. Sulphur dissolving bacteria

6. Blue Green Algae

7. Azolla : Azolla filiculoides, Azolla rubra

8. Vesicular Arbuscular Mycorrhizas

Plant growth promoting Rhizobacteria (PGPR)