The nitrogen cycle might be the most complicated of the three.
Nitrogen is fixed to the soil in nitrogen fixation. N2 -> NO3 Mineralization: organic matter (R) binds with nitrogen. R-NO3, R-NH2 Denitrification results in nitrates becoming nitrites. NO3 -> NO2 Volatilization means nitrogen gas, N2, is going back into the air. Leaching refers to nitrogen seeping into groundwater. This is inevitable but should be controlled to preserve water quality. The Nitrogen Cycle is regulated naturally by bacteria, legumes and organic matter. |