The Nitrogen Cycle

Like carbon, nitrogen also survives the earth, and in the nitrogen cycle, nitrogen circulates through the global environment. Nitrogen is also a chemical element, it is the richest element in the atmosphere, accounting for 78% of the atmosphere. Nitrogen is very different from other elements and can not be used directly as a nutrient for animals and plants such as oxygen and carbon. However, nitrogen may be converted to a form that can be used for animals and plants by lightning strikes and bacteria. When converted to usable form, nitrogen can circulate through the rest of the ecosystem

Humans are involved in the nitrogen cycle in various ways, but not all of them are beneficial. One of the most important roles people play in the nitrogen cycle is the introduction of nitrogen fertilizer into the soil. Since nitrogen has a strong influence on the growth of plants, farmers are keen to add more nitrate and / or ammonium to the crop so that the soil becomes saturated and therefore can not absorb further. When absorbing all the nitrogen that the soil can possess, it will eventually leach - the process of removing water-soluble soil material. In particular, nitrates penetrate groundwater from agricultural land, streams and other surface water. This can lead to eutrophication, increased state of biological productivity, which is ultimately harmful to ecosystems around the lake and other waters. (For details on eutrophication, see biogeochemistry cycle.)