How do biofertilisers enrich the fertility of the soil?

Biofertilizers are organisms that help in enriching the soil with nutrients. Example of few microbes that are common biofertilizers are as below:

• Rhizobium, Azospirillum and Azotobacter help in nitrogen fixation and hence, enrich the soil with nitrogen.

• Fungi such as mycorrhiza form symbiont relationship with plants and absorbs phosphorus from soil and passes it to the plant.

• Cyanobactaria help in nitrogen fixation and is an important biofertilizer.