What are biofertilizers ? Give two examples.

Explanation

Biofertilisers. Organic farming involves the use of biofertilisers instead of chemical fertilisers.
Biofertilisers are the organisms that enrich the nutrient quality of the soil. Diverse group of organisms such as bacteria, cyanobacteria and fungi are used as biofertilisers.
(i) Rhizobium-N.-fixing bacteria forms symbiotic association with roots of leguminous plants and produce root-nodules. These bacteria fix atmospheric nitrogen into organic compounds which are used by the plant as nutrient.
(ii) Azospirillum and Azotobacter are the free-living bacteria in soil which can fix atmospheric nitrogen, thus, enriching the nitrogen contents of the soil.
(iii) Mycorrhiza is a symbiotic association between fungus and the roots of higher plants. Fungal partner absorbs water, nitrogen, potassium and the phosphorus from the soil and passes it to plant.