All animals including human beings require proteins for survival. One such protein crucial for survival is nitrogen. Dry air contains approximately 78% of the nitrogen in volume and is the most abundant gas present in the atmosphere. Animals cannot absorb this nitrogen available directly from the air in order to synthesize proteins while certain plants can. Life would not function on the planet as there is no way to fix nitrogen from the air.
Nitrogen is required to produce amino acids which in turn produce proteins in both plants and animals. Living creatures cannot grow without fixing nitrogen. Some primitive bacteria may possibly sustain life without nitrogen cycle but plant life would just not be possible. The nitrogen cycle is a 5 step process with different stages, namely:
- Nitrogen fixation
We obtain our proteins from plants and excrete nitrogen in various forms and hence the nitrogen cycle continues. Nitrogen is known to be a key nutrient for animal and plant growth. It is fixed by a few bacteria present in the atmosphere naturally.
Nitrification is a biological process and a part of the nitrogen cycle wherein ammonium gets converted into nitrite and nitrate. Nitrate is the favored form of nitrogen which can be consumed by plants and plants are the primary producers of the ecosystem. Hence we derive our nitrogen requirements from plants.
It is a microbial process that takes place in the presence of oxygen wherein specialized bacteria present in the atmosphere oxidizes ammonium to nitrate. It is a two-step process wherein the first stage involves the bacteria of genus Nitrosomonas that are involved in the oxidation of ammonium to nitrite and the second step involves the bacteria of the genus Nitrobacter wherein nitrite is immediately oxidized to nitrate.
In comparison to ammonium, nitrites and nitrates are more mobile in the soil hence the process of nitrification is observed to be a process that mobilizes nitrogen hence making it easier in its uptake by plants.
Comparing Nitrification AndDenitrification
Nitrification and denitrification are two different stages in the nitrogen cycle, however, they differ. Listed below are a few differences:
- Nitrification is a part of the nitrogen cycle where ammonia is converted into nitrate whereas denitrification is also a part of the nitrogen cycle but in this stage, nitrate is reduced to nitrogen gas.
- The process of nitrification involves bacteria such as Nitrosomonas and Nitrobacter and the process grows at a slow pace whereas denitrification moves at a faster pace and involves bacteria such as Spirillium, Pseudomonas, Lactobacillus.
- Denitrification is an anaerobic stage whereas nitrification requires aerobic conditions.
- The microbes involved in the process of denitrification are heterotrophic wherein the outcome of the process is nitrogen. Nitrification, on the other hand, involves autotrophic microbes producing nitrate as the end product.
- The process of denitrification is utilized in wastewater treatment and is advantageous for aquatic inhabitants. The favorable temperature for denitrification is between 26-38and the pH range between 7-8.5. The process of nitrification supplies nitrate to plants and hence serves as an important source. The ideal temperature for nitrification ranges from 16-35and the suitable pH range is between 6.5-8.5.
Apart from the nitrogen cycle, there are other important biogeochemical cycles taking place simultaneously in the environment, such as:
- Nutrient cycle
- Carbon cycle
- Oxygen cycle
- Water cycle
- Phosphorous cycle
- Sulfur cycle
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