How do nitrogen fixing bacteria on root nodules function in the nitrogen cycle?

Answer 1

Although the air is made up of about 70% nitrogen, plants cannot use nitrogen in this N2 form. Nitrogen fixing bacteria change nitrogen into the form of soluble nitrates so that plants can use it. Other bacteria, known as de-nitrifying bacteria, change nitrates back into N2, which completes the nitrogen cycle. Some nitrifying bacteria lives in the roots of legumes, and do the same job.

Answer 2

Nitrogen-fixing bacteria in root nodules convert atmospheric nitrogen into a form that plants can use, such as ammonia. This process is called nitrogen fixation, and it helps to enrich the soil with nitrogen, benefiting the plant and other organisms in the ecosystem. The fixed nitrogen is then available for uptake by the plant, promoting its growth and overall health.