Question

Discuss about the Biofertilizers.

Answer 1

• Chemical fertilizers major pollutant.
• Switch to organic farming and use of biofertilizers need of the time.
• Main sources of biofertilizers. Bacteria, Fungi & Cyanobacteria. Eg Rhizobium present in roots of leguminious plants fix atmospheric nitrogen into usable organic form. Azospirillium and Azotobacter – free living bacteria – fix atmospheric Nitrogen.
• Symbiotic Associations Eg.Genus Glomus sp. form mycorrhiza.
• Fungal symbiont absorbs phosphorus from soil and passes it to plant.
• Plants show resistance to root – borne pathogens.
• Tolerance to salinity and drought.
• Increase in growth and development.
• Cynobacteria– autotrophic – fix atmospheric nitrogen Eg. e.g. Anabaena, Nostoc, Oscillatoria.
• Blue green algae – increase fertility by adding organic matter