Discuss the role of Microbes as Biofertilizers
Role of microbes as biofertilizers: Bacteria, cyanobacteria, and fungi (mycorrhiza) are the three groups of organisms used as biofertilizers. 1. Bacteria: (a) Symbiotic bacteria Rhizobium. (b) Free-living bacteria Azospirillum and Azotobacter. (c) They fix the atmospheric nitrogen and enrich soil nutrients. 2. Cyanobacteria, e.g. Anabaena, Nostoc, Aulosira, Oscillatoria, etc. (a) They function as biofertilizers by fixing atmospheric nitrogen and (b) Increasing the organic matter of the soil through their photosynthetic activity. Fungi/mycorrhizae: (a) Fungi form a symbiotic association with roots of higher plants (mycorrhizae), e.g. Glomus. (b) The fungus absorbs phosphorus and passes it on to the plant. (c) Other benefits of mycorrhizae are : resistance to root-borne pathogens. tolerance to salinity. tolerance to drought. the overall increase in the plant growth and development
