Most of the Earth’s atmosphere is nitrogen (78%). When humans and all living things take a deep breath, most of what they just inhaled is nitrogen. All life needs nitrogen compounds, for examples are proteins and nucleic acids. For the plants, chlorophyll molecules use most of the nitrogen which are important for photosynthesis and further development. The quantity of nitrogen gas being permanently at any given time by natural processes produces only a small increase by fixed nitrogen that rotates among the living and non-living components of the Earth’s ecosystem (Peter et al., 1997). Nitrogen cycle is the process where nitrogen is switched between its various chemical forms. The vital processes of nitrogen cycle are nitrogen fixation, nitrification, ammonification, assimilation and denitrification (Steven & Steven, 2004).
The first stage involved in nitrogen cycle is nitrogen fixation. The nitrogen gas from the atmosphere cannot be used directly by the plants, so it is converted to ammonia first (refer to figure 1). The process of converting nitrogen gas to ammonia is carried out by the bacteria that lived in the roots of legumes such as peas, soybeans, and peanuts (White, 1979). This bacterium is known as Rhizobium (Zahran, 1999). It acts as the primary nitrogen fixer by infecting the roots of leguminous plants which result in the formation of nodules where the process of nitrogen fixation takes place. The enzyme nitrogenase is responsible in catalyzing the entire reaction occurs during nitrogen fixation by adding electrons and hydrogen ion (Haider & Schaffer, 1993).
The second stage in the nitrogen cycle is nitrification which can further divide into two phase. The first phase is the oxidation of ammonia to nitrite. The ...
... middle of paper ...
...obert, L. S. (1990). Ecology and Field Biology (4th ed.). New York: NY: HarperCollin Publishers.
Schmidt, E. L. (1982). Nitrification in soil. Nitrogen In Agricultural Soils, (Nitrogen In Agrics), 22, 253-288.
Smil, V. (2000). Cycles of life. New York, NY: Scientific American Library.
Star, C., & Taggart, R. (2001). Ecology and behavior (9th ed.). Pasific Grove, CA: Brooks/Cole.
Steven, B. C., & Steven, D. S. (2004). Ecology of gardeners. New York, NY: Timber press.
Vitousek, P. M. et al, (1997). Human alteration of the global nitrogen cycle: sources and consequences. Acological Applications, 7, 737-750.
White, R. E. (1979). Principles and practice of soil science (4th ed.). London, UK: Blackwell Publishing.
Zahran, H. H. (1999). Microbiol mol boil rev. Rhizobium-Legume Symbiosis And Nitrogen Fixation Under Severe Conditions And In An Arid Climate, 63(4), 968-989.
Below is the graph of the cycle. The nitrogen cycle ties into the tropical rainforest also in many ways. One of them being that Nitrogen is a very important factor for all plants and animals. The nitrogen is brought into the soil and water when the plant dies it also can be brought into the soil when herbivores have eaten the dead plants or in some ways they can excrete nitrogen . Humans affect this cycle in many ways by adding extra nitrogen this can happen with fertilizers and this is releases nitrogen into the air with fossil fuel. In fact, humans add way more nitrogen to the air than the what actually comes from natural sources. Without the nitrogen cycle there would be very limited to non growth because the rainforest needs nitrogen in the
All of the plants in the nightshade family are nitrogen containing plants, including nicotine. Nitrogen is the second most important supplements for plant growth, below water. Nitrogen can be found in many different forms. It moves around natural ecosystems through the nitrogen cycle. The different forms of nitrogen decide its whether or not it is available to plants or whether it escapes and is no longer able to provide plants. The amount of useable nitrogen and the percent that is lost from the soil affects the supportability of productivity. If it is mishandled it is possible to have economic loss to the producer and have an environmental
The leguminosae family, more commonly known as the legume, pea, or bean family; contain most of the plant species that form a symbiotic relationship with nitrogen fixing bacteria. About 20,000 species of legumes form their symbiosis with rhizobia; a nodule-inducing bacteria. Legumes have emerged as a very valuable resource for many countries for various reasons. The seeds of legumes are very high in protein, and some can also be rich in oil. Some countries donate up to 60% of their arable land in order to plant various types of this plant family. This family of plants is also used to enhance soil fertility and is a valuable source of wood. In various agricultural systems, the need for chemical fertilizer is greatly reduced due to the nitrogen fixation of the symbiotic bacteria that is hosted by the legumes. In some areas, almost 50% of the nitrogen added to the soil is due to this symbiotic relationship (3). Although an exact estimate of this symbiosis is hard to determine, legume-rhizobia relationships remain important to the function and composition of many natural ecosystems throughout the world (2).
Loder, Natasha, Elizabeth Finkel, Craig Meisner, and Pamela Ronald. “The Problem of What to Eat.” Conservation Magazine. The Society for Conservative Biology, July-Sept. 2008. Web. 16 Dec. 2009.
Nitrogen can be considered as both a fertilizer and nutrient under the right constraints. I will use citrus plants as one of my examples. For citrus growers applying nitrogen to plants is a common and needed practice. “Spring is the best time to apply nitrogen to citrus. Research has shown that the demand for nitrogen in citrus is highest from bloom through June and most of the supplemental nitrogen fertilizer should be applied during this time period.” It is a major key to plant growth and development. Nitrogen is crucial to citrus plants for optimal growth and yield. Without nitrogen you can see suffering results for many years down the road.
Scott, Heidi. "Crazed Nature: Ecology In The Yellow Wall-Paper." Explicator 67.3 (2009): 198. MasterFILE Complete. Web. 23 Apr. 2014.
Seideman, D. (1993). Out of the Woods: Vol. . A Forest of Voices (2nd ed.) [Conversations in Ecology].Mayfield.
2. (2 pts) Contrast the potential contributions of Azotobacter versus Rhizobia/Bradyzhizobia to the nitrogen budget in soils. Discuss why they are so different.
The knots on the roots of leguminous plants (i.e., clover, beans, peas, alfalfa) contain bacteria belonging to the genus Rhizobium. While growing together with the plants, this genus Rhizobium gathers nitrogen from the air and combines it into substances essential for the growth of both the bacteria and the plants. The process is known as symbiotic nitrogen fixation
In addition, several studies indicate that potential soil nitrification effects differ among ecosystems, and that these differences do not seem to be associated directly with physical or chemical soil characteristics (Clark et al., 1960, Hattenschwiler and Vitousek, 2000; Lata et al., 2004; Laverman et al. 2000; Lovett et al. 2004; Montagnini et al. 1989; Northup et al. 1995; Robertson, 1982 a, Robertson, 1982 b and Schimel et al., 1998). In several other studies, it was shown th...
The next topic for discussion in this paper is ecology. This will include, preferred habitats and interactions with abiotic and biotic elements of the environment.
Nitrogen fertilizers: firstly nitrogen is found in the air, so air is pumped into a large vessel. The air is warmed and oxygen is removed becoming steam. This leaves hydrogen, nitrogen and carbon dioxide. To remove the carbon dioxide an electric current is introduced into the system. And finally remains ammonia. Ammonia is further processed adding air to the solution and making nitric acid. In conclusion when ammonia and nitric acid are combined is made ammonium nitrate, the component used as fertilizers.
... growth of plants through nitrogen fixation. It is obtain through precipitation is also passed along the food chain through shell fragments and eating other organisms. Therefore, it is evident that these nutrient, oxygen and nitrogen cycles in the biosphere has significantly contribute to the unique functioning leading to diverse ecosystem of coastal dunes.
Venus and Mars' atmospheres have both been found to have traces of nitrogen. Though the nitrogen in each of the atmospheres varies from 2.7% to 3.5% the substance is nonetheless present. The theories of how nitrogen enters the atmosphere differ for the two planets. The generation of nitrogen on Mars is believed to be caused by outgassing from the planets local volcanoes. While the generation of nitrogen on Venus is believed to be from the lack of a magnetic field around the planet’s atmosphere.
...eochemical cycles. By increasing the amount of crops that are removed from the soil and the subsequent soil erosion, phosphorus levels in the soil have dropped. The phosphorus lost from the soils travels to aquatic ecosystems which then can cause massive algal blooms. The increased use of nitrogen based fertilizers has also altered that cycle. The fertilizers add high levels of nitrates to the soil, and in natural ecosystems, nitrates will undergo denitrification and be returned as atmospheric nitrogen. This is not the case because the nitrate levels exceed the levels of denitrification that bacteria can handle. Additionally, much of the denitrifying bacteria is found in marshes and wetlands, which are currently being destroyed at incredible rates. In some areas, the excess nitrate has made it into the ground water system and contaminated the drinking water system.