Question

Bio-fertilizers include:

• A. Nitrogen fixing bacteria
• B. Nitrogen fixing cyanobacteria
• C. Both bacteria and cyanobacteria
• D. Bacteria, cyanobacteria and mycorrhizal fungi

Answer 1

The correct option is D Bacteria, cyanobacteria and mycorrhizal fungi

Bio-fertilizers are microorganisms which bring about the nutrient enrichment of soil by enhancing the availability of nutrients to crops. The microorganisms which act as bio-fertilizers are bacteria, cyanobacteria (blue-green algae) and mycorrhizal fungi. Bacteria and cyanobacteria have the property of nitrogen fixation while mycorrhizal fungi preferentially withdraw min­erals from organic matter for the plant with which they are associated.