Effects of Agriculture on the Nitrogen Cycle

Connecticut

Ecosystem

Relation to the Biogeochemical Cycle

Two parts of Connecticut are especially susceptible to eutrophication; Long Island Sound and Candlewood Lake. When high amounts of nitrogen enter these waters, algae and phytoplankton grow at rapid rates. An abundance of algae causes, a depletion of oxygen in the water, this creates a dead zone. Long Island Sound has three instances a year where hypoxia, or low oxygen levels, occur. These episodes usually occur during the summer, and the conditions have worsening every year. Hypoxia causes fish to scatter and become very susceptible to disease, and in extreme cases, when oxygen levels become extremely low, fish and other shellfish may die. Excessive amounts of nitrogen can contaminate the water and the shellfish. This can cause people who come in contact with the tainted shellfish to become ill. This can happen in both Candlewood Lake and Long Island Sound, and even other bodies of water in Connecticut.

Nitrogen

Cycle

Farmer's need to grow a large amount of plants in a small area. Each one of these plants needs nitrogen to produce chlorophyll and grow to provide food. Plants can only absorb nitrogen in the forms of nitrate and ammonium. Farmers often find that their is not enough nitrate and ammonium in the soil to support such drastic growth, so they manipulate the nitrogen cycle by giving their plants nitrogen based fertilizers. Nitrogen fertilizers are made using the Haber Bosch Process which combines nitrogen from the air with hydrogen to produce ammonia. Doing this on a large scale can affect the balance of the nitrogen cycle and how much nitrogen gases (some of which are important greenhouse gases) are in the atmosphere.

The nitrogen cycle is the process of the circulation of nitrogen in which it passes through the food chain, the soil, and the open air. In this cycle, nitrogen is passed through plants through fertilizers so that plants/food grow larger and faster. This fertilizer also reaches bodies of water where the plants and animals in the water inhabit (?)the nitrogen passed along. Eventually, humans eat the grown foods from either plants or animals on land and in water, and receive the nitrogen that was once applied by the fertilizer. Therefore, the rotation of nitrogen being transferred through the environment and humans, is continuous.

Fertilizers impact

Works Cited

• "Dead Zone." National Geographic Education. N.p., n.d. Web. 26 Oct. 2015.
• "Nitrogen Cycle." - Biology-Online Dictionary. N.p., n.d. Web. 29 Oct. 2015.
• "The Nitrogen Cycle." The Nitrogen Cycle. N.p., n.d. Web. 29 Oct. 2015.
• "CT Fund for the Environment & Save the Sound." CT Fund for the Environment & Save the Sound. N.p., n.d. Web. 29 Oct. 2015.
• "Haber Bosch Process." <i>Encyclopedia Brittanica</i>. N.p., n.d. Web. 31 Oct. 2015.
• "Agriculture." <i>HSC Online</i>. N.p., n.d. Web. 31 Oct. 2015.

Fertilizer has a huge impact on the nitrogen cycle. When we cause nitrogen overload in an ecosystem, there are many drastic effects. Dumping of raw sewage contains nitrogenous wastes, along with urban runoff. When large amounts of nitrogen collect in a water body, eutrophication can result. This is an accumulation of excess nutrients which causes an algae bloom. The algae rapidly deplete all of the oxygen in the water, making it inhospitable for fish and other aquatic organisms. Eutrophication also brings about the deadly red tides. When plant communities are saturated with nitrogen, the soil can become acidified. This makes the soil inhospitable. Burning fossil fuels and wood contributes to a large amount of nitric oxide in the atmosphere. Nitric oxide can combine with oxygen gas to form nitrogen dioxide, which reacts with water vapor to form a strong acid (nitric acid). This can precipitate out of the atmosphere in the form of the deadly acid rain. The acid can damage trees and kill fish. The use of inorganic fertilizers and depleting nitrogen resources by over harvesting legumes (which have nodules in their roots formed by a symbiotic bacteria that fix nitrogen) and over mining nitrogen also alter an ecosystem

If the Problem is Not Addressed...

The rise in rigorous agricultural practices have caused large amounts of nitrogen to be emitted into the air, soil, and water causing dead zones. Dead zones are areas in the water that are low in oxygen, and can occur in freshwater and oceans. When farmers use soils high in nitrogen, the excess amount ends up leaking into the water through runoff. When too much nitrogen enters the water, immense amounts of algae begin to grow, which is the cause of dead zones. Because organisms need oxygen to live, the dead zones, which are low in oxygen, cause them to die off. Therefore, if this problem is not addressed, and farmers do not cut down on their usage of (??)soils containing nitrogen, more dead zones will appear and cause death to many organisms.

The Effects of Agriculture on the Nitrogen Cycle

By: Amanda, Jeremy, Matt, Henry, Dani