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Nitrogen is an important protein, not made by animals, but required by the body. As the cycle goes, it can be obtained
by eating animals and plants. In the field of agriculture, nitrogen is the main component in fertilizer and makes plants
grow faster and fuller. It is also used in the detonation of explosives. Nitrogen is mainly based in the troposphere, where
it is also more abundant then any other element at 78%. However, nitrogen is useless in its gaseous form and must be converted
to a protein consumable for plants and animals. In order to do so, it undergoes a process called nitrogen fixation. This process
begins the nitrogen cycle.
Nitrogen cycles through the lithosphere
and atmosphere where it is transferred through organic and non-organic materials. To begin the cycle, the gaseous nitrogen
in the atmosphere reacts with gaseous oxygen due to powerful sources of heat and energy such as lightning, volcanic
eruptions and forest fires. This forms the compound nitrogen oxide (2NO). Proceeding after the formation of nitrogen oxide,
the compound becomes nitrogen dioxide (2NO2) through oxidation, which is a reaction with oxygen. Nitrogen dioxide is easily
converted to ammonia (NH3) through a reaction between it (2NO2) and rain water (H2O) where it drops to the lithosphere and
seeps into the soil. Another form of nitrogen fixation involves microorganisms that are bacteria and have the
capability to convert nitrogen to nitrate (NO3) naturally. In a mutual relationship with some plants, they provide
the plant with nitrogen along with providing the soil with the nutrient.
Plants uptake the nitrate, that are only located beneath the surface in the soil, through their
extensive root systems. Nitrate can also be consumed by the organisms that inhabit the soil such as bugs and other microorganisms.
The plants and bugs are eaten by larger animals and the presence of nitrogen continues to the very top of the food
chain. Nitrogen is continually returned to the soil through animal waste and the bodies of dead and decaying organisms.
Once back in the soil, microorganisms breakdown the remaining nitrates into its previous form of ammonium. This process is
known as mineralization. A further decay by specific bacteria and a reaction with oxygen causes a process called nitrification
to occur. During this process, the nitrogen in the form of ammonium is converted back to nitrate by bacteria. These nitrates
are the source for more energy to be consumed by plants and for nitrogen to be returned back to the air. In a process called
denitrification, the nitrate (NO3) compound is broken down by bacteria into its original gaseous form (N2) and released at
the surface where it returns to the troposphere and can repeat the cycle again and again.
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