Nitrogen in its gaseous form (N2) can’t be used by most living things. It has to be converted or ‘fixed’ to a more usable form through a process called fixation. Biologically: Nitrogen gas (N2) diffuses into the soil from the atmosphere, and species of bacteria convert this nitrogen to ammonium ions (NH4+), which can be used by plants.
Question- What is the one way nitrogen may be returned to the air?
Answer- Nitrogen fixation
Further Explanation On Answer- Nitrogen fixing bacteria in root nodules of legumes fix nitrogen from the atmosphere into ammonia. This is the natural equivalent of the Haber process. Nitrification: Nitrites and Nitrate are produced from ammonium by Nitrifying bacteria.
