Question

A biofertilizer is

• A. a cyanobacterium like Anabaena sp living in cavities of Azolla leaves
• B. Symbiotic bacteria like Azotobacter which fix atmospheric nitrogen
• C. farm yard manure consisting of mixture of cattle dung and crop
• D. green manure in which quickly growing crop is cultivated and ploughs under

Answer 1

The correct option is A a cyanobacterium like Anabaena sp living in cavities of Azolla leaves

Biofertilizers are those organisms which can bring about enrichment of soil. For example the leaves of Azolla house colonies of the cyanobacteria Anabaena which fix atmospheric nitrogen for the plant to make use of. Azotobacter is also a fertilizer but it is a free – living nitrogen fixing cyanobacteria.