EVERYDAY SCIENCE

Detailed explanation-1: -Nostoc is blue-green algae that fixes atmospheric nitrogen into ammonia and the plants can use this ammonia for their living processes. Thus nostoc acts as a free-living or symbiotic nitrogen-fixing bacteria for the plants and therefore, is used as a biofertilizer.

Detailed explanation-2: -Biofertilizers today Biofertilizers such as Rhizobium, Azotobacter, Azospirilium and blue green algae(BGA) have been in use a long time. Rhizobium inoculant is used for leguminous crops. Azotobacter can be used with crops like wheat, maize, mustard, cotton, potato and other vegetable crops.

Detailed explanation-3: -Azolla-Anabaena as a Biofertilizer for Rice Paddy Fields in the Po Valley, a Temperate Rice Area in Northern Italy.

Detailed explanation-4: -Biofertilisers are the organisms that enrich soil nutrient quality. Azolla is used as a biofertilizer because it possesses a symbiotic association with Nitrogen fixing cyanobacteria.

Detailed explanation-5: -The main sources of bio-fertilisers are bacteria, fungi and cyanobacteria. 5. Rhizobium is a free-living bacterium that fixes atmospheric nitrogen.