To begin, it is necessary to know what the term nitrogen means, this is a chemical element whose symbol is "N". The earth's atmosphere is composed of this element in 78%, making it one of the most abundant elements on earth. This element is extremely important for living beings, since thanks to it it is possible to carry out most of the most significant biological processes.
The nitrogen cycle, therefore, is a biogeochemical cycle that is distinguished by the transit of nitrogen through different chemical and biological changes on the planet. This cycle usually repeats itself over and over again, that is, the air passes to the ground and vice versa. It is characterized by being a very complex cycle, since the element has to go through different processes until it returns to the atmosphere.
The stages through which nitrogen must pass are the following:
Fixation: this represents the first step for nitrogen to be fixed in the earth's atmosphere, this can occur thanks to the action of lightning flashes or by the activity of some bacteria, which bind nitrogen to plants.
Ammonification: the soil is full of bacteria, these bacteria have enzymes that transform gaseous nitrogen into ammonium ions that end up adhering to the soil.
Nitrification: once nitrogen is in the soil, another group of bacteria convert ammonia and ammonium into nitrite, which will then be transformed into nitrate.
Assimilation: plants absorb nitrate found in the soil and use it to make proteins, which are passed to animals through the food chain. This cycle starts again when animals and plants die.
Denitrification: a part of this nitrate found in the soil is lost during the denitrification process. Through this process, certain bacteria modify nitrate and nitrogen gas, releasing it into the atmosphere.
The importance of nitrogen lies in the benefits it provides to living beings. Nitrogen is essential for plant and animal cells to function effectively. Plants, for their part, need nitrogen to develop and produce seeds.
Both plants and animals cannot directly absorb nitrogen, which is why the nitrogen cycle is of vital importance to them.
