Answer:
Starting from the air
Explanation:
First Nitrogen in the air makes its way into the soil where nitrogen fixation occurs. This is done by specialised nitrogen fixing bacteria where it either becomes ammonia or ammonium. This is called ammonification. Nitrifying bacteria uses these components to create nitrates and the cycle moves into assimilation where this is taken up by plants and animals. Finally, denitrification occurs when the organic matter that took up the nitrogen decomposes to release the nitrogen back into the air.
