Nitrogen fixing bacteria ?

Nitrogen fixation is the essential biological process and the initial stage of the nitrogen cycle. In this process, nitrogen in the atmosphere is converted into ammonia (another form of nitrogen) by certain bacterial species like Rhizobium, Azotobacter, etc. and by other natural phenomena.

Plants are the main of the sources of food. The nutrients obtained from plants are synthesized by plants using various elements which they obtain from the atmosphere as well as from the soil. This group of elements includes nitrogen as well. Plants obtain nitrogen from the soil through the process of protein synthesis. Unlike carbon dioxide and oxygen, atmospheric nitrogen cannot be obtained through stomata of leaves. Because the concentration of nitrogen gas present in the atmosphere can not be directly used by plants and also the concentration of the usable form of nitrogen in the atmosphere is very less. There are certain bacteria and some natural phenomenon which help in Nitrogen fixation.