The steps of the nitrogen cycle are nitrogen fixation, nitrification, ammonifcation and denitrification. During the first step, nitrogen fixation, special bacteria convert nitrogen gas into ammonia which is used by plants. The second step, nitrification, involves converting ammonia into nitrite ions that are taken by plants as nutrients.
After living organisms have used the nitrogen, the next step in the cycle is ammonification, in which decomposing bacteria convert the waste compounds that are rich in nitrogen into simpler compounds.
The last step in the nitrogen cycle is denitrification, wherein bacteria convert simple nitrogen compounds back into nitrogen gas, which then returns to the atmosphere and starts the cycle again. In this cycle, plants absorb nitrogen, and then animals consume the plants. When bacteria decompose the animals, nitrogen is released back into the soil, leading into a continuous and repetitive cycle. Nitrogen is converted into different chemical forms, with both biological and non-biological methods used in the cycle.
Nitrogen is the most abundant and most valuable gas for all organisms on Earth. It exists in proteins which are the building blocks of life among humans and all other organisms. Although nitrogen is a component of air, it is not in usable form; that’s why bacteria need to convert the atmospheric nitrogen into compounds that living beings can use, and this process is the nitrogen cycle.