Question

What are biofertilizers main sources? 

Answer 1

The main sources of biofertilizers are bacteria, fungi, and cyanobacteria. Key examples include Rhizobium bacteria (symbiotic with legume roots fixing atmospheric nitrogen), free-living nitrogen-fixing bacteria like Azospirillum and Azotobacter, cyanobacteria such as Anabaena and Nostoc, mycorrhizal fungi, phosphate-solubilizing bacteria and fungi, and actinobacteria like Frankia. These microbes enhance soil fertility by fixing nitrogen and solubilizing nutrients for plant use.