Question

Name the different types of microorganisms used as bio-fertilizers in organic farming and explain how each contributes to soil fertility. 

Answer 1

Biofertilisers are living microorganisms that enrich soil nutrients and improve plant growth.

1. Rhizobium: Forms root nodules on legumes and fixes atmospheric N2 into plant‑available nitrogen, raising soil N.
2. Azotobacter/Azospirillum: Fix atmospheric N in the rhizosphere or inside roots of non‑legumes, supplying N and promoting root growth.
3. Mycorrhizal fungi: Extend root uptake via fungal hyphae, increase phosphorus and micronutrient uptake, improve water uptake and soil structure.