Nitrogen Cycle is a biogeochemical process where atmospheric nitrogen is passed to soil , plants ,animals and humans then is returned to the atmosphere again.Nitrogen is absorbed by the soil then fed to the plants by means of nitrogen fixing bacteria living in legume root nodules or undergoes ammonification by means of nitrogen fixing soil bacteria.Animals and humans consume plants then make wastes which are decomposed by means of bacteria and fungi to ammonium compounds.Ammonium compounds is changed to nitrates(NO2) by means of nitrification soil bacteria , then changed to nitrates (NO3).Nitrates (NO3) is then fed to certain plants or decomposed by denitrifying bacteria and nitrogen is freed to the atmosphere again.
