Diazotroph

[3] Fixation is shut off when other sources of nitrogen are available, and, for many species, when oxygen is at high partial pressure.

Under the laboratory conditions, extra nitrogen sources are not needed to grow free-living diazotrophs.

Carbon sources (such as sucrose or glucose) and a small amount of inorganic salt are added to the medium.

[12] From the ancient time, people grow the leguminous crops to make the soil more fertile.

Diazotroph biofertilizers used today include Rhizobium, Azotobacter, Azospirilium and Blue green algae (a genus of cyanobacteria).

These nitrogen-fixation fertilizer has a certain effect on increasing the production of cotton, rice, wheat, peanuts, rape, corn, sorghum, potatoes, tobacco, sugarcane and various vegetables.

In organisms the symbiotic associations greatly exceed the free-living species, with the exception of cyanobacteria.

In the terrestrial ecosystem, the diazotroph fix the (N2) from the atmosphere and provide the available nitrogen for the primary producer.

Also the available nitrogen fixed by the diazotroph is environmentally sustainable, which can reduce the use of fertilizer, which can be an important topic in agricultural research.