1. Fixation (bacteria converts nitrogen to ammonium so plants can use it)
2. Nitrification (bacteria changes ammonium to nitrates and plants absorb these nitrates)
3. Assimilation (plants absorbs nitrates it is then used for chlorophyll, nucleic, and amino acids)
4. Ammonification (plant or animal dies and turns nitrogen back into ammonium through decomposition)
5. Denitrification (bacteria release nitrogen into the air)