What are the 7 parts of the nitrogen cycle

The nitrogen cycle is a natural process that describes the movement and transformation of nitrogen through various forms in the environment. The nitrogen cycle involves several major processes and steps. Although there is no universally agreed division into seven parts, the nitrogen cycle is often conceptualized with the following main components:

What are the 7 parts of the nitrogen cycle

Nitrogen fixation:

Nitrogen fixation is the process by which atmospheric nitrogen (N2) is converted into ammonia (NH3) or other nitrogen compounds. This can be done by nitrogen-fixing bacteria, some of which live in the soil, or form symbiotic relationships with some plants.


Ammonification is the decomposition of organic nitrogen compounds into ammonia (NH3) by bacteria and other microorganisms. This process occurs when organic matter, such as dead plants or animal remains, breaks down.


Nitrification is the conversion of ammonia (NH3) to nitrite (NO2-) and then to nitrate (NO3-) by specific bacteria. These bacteria are called nitrifying bacteria and they play an important role in providing nitrogen compounds to plants.


Assimilation involves the incorporation of nitrate (NO3-) or ammonium (NH4+) by plants into their tissues. Plants assimilate nitrogen to form proteins, nucleic acids and other essential organic molecules.

Nitrate leaching:

Nitrate leaching is the process by which nitrate (NO3-) is removed from soil by water. This can lead to the loss of nitrogen from the soil, affecting both terrestrial and aquatic ecosystems.


Denitrification is the conversion of nitrate (NO3-) and nitrite (NO2-) back into nitrogen gas (N2) or nitrous oxide (N2O) by bacteria. This process releases nitrogen back into the atmosphere, completing the cycle.

Ammonium Evaporation:

Ammonium volatilization occurs when ammonium (NH4+) is converted to ammonia (NH3) gas and released into the atmosphere. This process is affected by environmental factors such as pH and temperature.

These phases represent key processes in the nitrogen cycle, highlighting the transformation of nitrogen between different forms and its movement through the atmosphere, soil, and living organisms. Keep in mind that the nitrogen cycle is a dynamic and interconnected system, and the boundaries between these phases are not always distinct, as nitrogen is constantly undergoing changes.