What is the main advantage of using biofertilisers in agriculture?

Step-by-step solution

Biofertilisers are organisms that enrich the soil's nutrient quality and reduce the dependence on chemical fertilisers, thus reducing environmental pollution. The nodules on the roots of leguminous plants formed by the symbiotic association of Rhizobium. These bacteria fix atmospheric nitrogen into organic forms, which is used by the plant as nutrient. Other bacteria can fix atmospheric nitrogen while free-living in the soil (examples Azospirillum and Azotobacter), thus enriching thenitrogen content of the soil.