Q.Justify the role of microbes as a bio-fertilizer.

Step 1. Biofertilisers are formulations of living microorganisms that enrich the nutrient quality of soil and improve its physico-chemical properties, such as structure, texture, water-holding capacity, cation-exchange capacity and pH.

Step 2. Rhizobium symbiotically fixes atmospheric nitrogen within the root nodules of leguminous plants, converting it into organic nitrogen forms the plant can absorb, while free-living bacteria such as Azospirillum and Azotobacter independently fix atmospheric nitrogen and enrich the surrounding soil.

Step 3. Mycorrhizal fungi (e.g. Glomus species) absorb phosphorus from the soil and transfer it to their host plant, additionally conferring resistance to root-borne pathogens and tolerance to salinity and drought, while nitrogen-fixing cyanobacteria such as Nostoc and Anabaena are especially valuable in water-logged paddy fields and also secrete plant-growth-promoting substances. …

Justify the biofertiliser role by naming specific organisms, the nutrients/benefits each provides, and the sus …

• Listing organisms without explaining what nutrient or soil benefit each specifically provides. …