How do biofertilisers enrich the fertility of the soil?
Bio-fertilizers are living organisms which help in increasing the fertility of soil. It involves the selection of beneficial micro-organisms that help in improving plant growth through the supply of plant nutrients. These are introduced to seeds, roots, or soil to mobilize the availability of nutrients by their biological activity. Thus, they are extremely beneficial in enriching the soil with organic nutrients. Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen. Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants.
Azospirillium and Azotobocter are free living nitrogen-fixing bacteria, whereas Anabena, Nostoc, and Oscillitoria are examples of nitrogen-fixing cyanobacteria. Biofertilizers are cost effective and eco-friendly.
Relation between bacteria and legume having nodulated roots is that of
Azotobacter and Bacillus polymyxa are
Azolla possesses symbiotic association with
Which is correct about nitrogen fixation by legumes. They fix nitrogen through
Azolla is used as biofertilizer as it has