Mention the role of cyanobacteria as a biofertilizer?

Hint: Biofertilizers are the microorganism which brings about soil nutrient enrichment, maximizes the ecological benefits, and minimize the environment.

Complete answer: The most suitable source of biofertilizer is achieved by the use of biofertilizers by the use of cyanobacteria (Blue-green algae), particularly in rice fields.
1. These organisms grow well in rice fields. These organisms grow well in symbiotic association with other plants or as free-living individuals on the surface of moist soil or under waterlogged conditions.
2. More than one hundred species and strains of nitrogen-fixing cyanobacteria are known.
Some of them are - Anabaena, nostoc, phalaenopsis, aulosira, chlorogloea, Cylindrospernum, Calothrix, Scytonema, Tolypothrix, wollea, etc.
3. The forms of cyanobacteria that posses heterocysts are considered associated with atmospheric nitrogen fixation.

Additional information: In India, the soil conditions in rice fields provide a suitable environment for the growth of nitrogen-fixing cyanobacteria.
1. They have the ability to provide the total nitrogen requirement of the rice crop and soil needs no chemical fertilizer of nitrogen.
2. These organisms have the potential to provide about 7-8 lakh tonnes of biologically fixed nitrogen to the rice cultivation, area per season in our country.
3. On average, the application of cyanobacteria can provide 20 -30 kg of biologically fixed nitrogen per hectare under normal conditions which can be doubled if optimum amounts of phosphate and molybdenum are available in the soil.

Note: The cyanobacterial biofertilizer is of many advantages and economical to the farmers because of:-
1. Its simplicity of operation
2. Easy adaptability
3. Storage facility.
The dried flakes of this biofertilizer can be stored for over 2-3 years without any loss in its viability.