Cyanobacteria are one of the main sources of biofertilizers which add organic matter to the soil and increase its fertility in paddy field.
Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments. These microbes replenish soil nutrients and reduce dependence on chemical fertilizers greatly.
Important examples of cyanobacteria are Anabaena, Nostoc and Oscillatoria.