a. Farmers prefer biofertilizers to chemical fertilizers because.
1. They help to get high yield of crops by making the soil rich with nutrients and useful microorganisms necessary for the growth of the plants.
2. Chemical fertilizers make the environment polluted by releasing harmful chemicals.
3. Biofertilizers destroy those harmful components from the soil that cause diseases in the plants.
4. Biofertilizers are environment friendly and protect the environment against pollutants.
b. Fungi are known to form symbiotic association with plants called Mycorrhiza. Many members of the genes Glomus forms mycorrhiza. The fungal symbiont in this association absorbs phosphorous from soil. Arbuscular mycorrhizal fungi play a vital role as a phosphatic biofertilizer.
Cyanobacteria are autotrophic microbes widely distributed in aquativ terrestrial environments many of which can fix atmospheric nitrogen, e.g., Anabaena, Nostoc, Oscillatoria, etc.