Nitrogen Cycle- Definition, Steps, Process, Significance

The movement of nitrogen between the atmosphere, biosphere, and geosphere in different forms is called the nitrogen cycle and is one of the major biogeochemical cycles.

• It may also be considered as the movement of nitrogen through the food chain from simple inorganic compounds, mainly ammonia, to complex organic compounds.
• This complex cycle involves bacteria, plants, and animals.
• All organisms can convert ammonia (NH₃) to organic nitrogen compounds that are compounds containing C–N bonds. However, only a few microorganisms can synthesize ammonia from nitrogen gas (N₂).
• Although N₂ gas makes up about 80% of the earth’s atmosphere, it is a chemically unreactive compound and thus needs to be changed in order to be utilized by living beings.
• Within the biosphere, there is a balance between total inorganic and total organic forms of nitrogen.
• The conversion of organic to inorganic nitrogen comes about through catabolism, de-nitrification, and decay.