What is the role of nitrogen-fixing bacteria in the nitrogen cycle

Nitrogen-fixing bacteria are  microorganisms capable of transforming atmospheric nitrogen into fixed nitrogen (inorganic compounds usable by plants).

A commonly known fact : More than 90 percent of all nitrogen fixation is effected by these organisms, which thus play an important role in the nitrogen cycle.

Explanation: Hope it helps:)

i think that you are smart and you should fit for it out