Biofertilizers are organisms that enrich the nutrient quality of the soil. Which of the following can be used as biofertilizers?
Nitrogen fixing cynobacteria
Nitrogen fixing bacteria
Mycorrhizae
All of these
As we have already discussed in Microbes as Biofertilizers -
Blue green algae
- wherein
They add organic matter to the soil and increase its fertility
Hence, the correct option is (d).