This article throws light upon the nine important groups of bio fertilizers. The groups are: 1. Azolla-Anabaena Symbiosis 2. Nitrogen-Fixing Bacteria Rhizobium 3. Diazotrophs 4. Frankia 5. Cyanobacteria 6. Phosphate Solubilizing Bacteria 7. Phosphate-Solubilizing Fungi 8. Plant Growth Promoting Rhizobacteria (PGPR) 9. Mycorrhiza for Sustainable Agriculture. 1. Azolla-Anabaena Symbiosis: Azolla is the globally distributed small […]