Environmental Conservation with GMOs
The introduction of GM crops into agriculture contributes to ecology conservation in several ways. Genetically engineered crops reduce much of the ecology destruction caused by current farming methods and bring about more environmentally-friendly farming techniques.
How do GM Crops Improve Soil, Water, & Air Quality?
SOIL & WATER
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Reduction in Insecticide Pollution
Currently, conventional agricultural methods involve the use of approximately 500,000 kg of pesticides each year (Council for Biotechnology Information, 2003). These practices involve the spraying of pesticides directly onto fields through the use of tractors or planes. Spraying is oftentimes inefficient because most of the active ingredients do not reach their target organisms. As a result, these excess amounts of pesticides pollute the environment as they absorb into the soil and water (Panos Briefing,1999).
GM crops can reduce the amount of these contaminants in the environment by localizing the pesticides within the crops. The insertion of the Bt gene from the Bacillus thuringiensis (Bt) bacterium into crops such as cotton, corn, and potatoes allow them to express the insecticidal proteins within parts of their plants (Shelton et. al.,2002). As a result, farmers can control the location of the toxin and prevent the spread of insecticides to unintended areas such as to the soil and water.
The use of Bt crops has the ability to reduce the total use of insecticides worldwide by 14%, approximately 163 million pounds per year (Agricultural Biotechnology in Europe, 2004) . In 2001, US Bt cotton farmers used 8 million pounds less insecticides. These dramatic reductions in pesticides will decrease the amount of contaminants that will enter the soil and water, preventing further disruption of the chemistry of these natural resources (Council for Biotechnology Information, 2003).
Reduction in Herbicide Pollution
Conventional farming involves the application of complex regimens of herbicides several times a year. Combinations of narrowly targeted and persistent herbicides such as atrazine and 2,4 D are oftentimes used by farmers to control weeds without killing crops (Paoletti et. al., 1996). This method of weed control involves the release of large quantities of herbicides into the environment, which can build up in the soil and run-off into water sources. As a consequence, organisms that thrive in the nearby soil and water may be adversely affected by the harsh chemicals.
The development of herbicide-resistant crops simplifies the weed control process for farmers. These transgenic crops are created by developing plant resistance to an herbicide known as glyphosate. The most popular variety of these herbicide resistant crops is the Roundup Ready soybean manufactured by Monsanto. Spraying of Roundup herbicide onto cropland will kill weeds, yet leave crops unharmed (Panos Briefing, 1999). Herbicide-resistant crops reduce the number of herbicide sprays needed each season. Only a few applications a year of Roundup to crops is sufficient for weed maintenance (Agricultural Biotechnology in Europe, 2003). This convenience of GM soybeans is appealing to farmers, as shown in the fact that one-third of soybeans in the United States are Roundup Ready varieties (Rauch, 2004).
The reduced use of herbicides will ensure that fewer chemicals seep into unintended areas of the environment. Herbicide resistant crops allow farmers to maintain the richness of soil and cleanliness of water without having to introduce more chemicals into the environment.
Less Soil Compaction
GM crops will lead to minimal soil compaction due to the reduced need to go onto farmland to spray crops. Reduced soil compaction puts less pressure on the natural ecosystem within the soil, making it a healthier habitat for non-target organisms (Council for Agricultural Science and Technology, 2003).
Decrease in Soil Erosion
Herbicide resistant crops enhance the ability to practice no-till farming, a technique that has numerous benefits to soil structure. No-till farming is beneficial to the environment because it does not involve plowing. Plowing disrupts the natural ecosystem of the soil. No-till farming, on the other hand, causes minimal disturbance to the soil by allowing plant residue to protect the soil's surface (Conservation Technology Information Center, 2002). In this way, it helps maintain soil structure and prevent erosion. The preservation of nutrients in the soil through no-till farming leads to lower levels of phosphorus, nitrogen, and sediment run-off into water sources. Sedimentation affects the habitat of fish and crustaceans by covering up their gravel beds. High levels of nitrogen and phosphorous disrupt the chemical composition of water. Although this farming system is beneficial to the soil, it requires a large amount of expensive and complicated herbicides to control the weeds that would otherwise be maintained through plowing. The ease of using herbicide tolerant crops improves the farmer's ability to practice no-till farming (Council for Biotechnology Information, 2003).
Since the introduction of herbicide tolerant crops into agriculture in 1996, the number of no-till conservation farming has increased by 35% Clearly, these GM varieties help alleviate much of the hard work associated with weed control, making this environmentally-friendly farming system a more viable option for farmers. As a result, herbicide resistant crops are beneficial to the environment because they enable farmers to practice conservative till farming (Council for Biotechnology Information, 2003).
Use of more benign compounds
Herbicide resistant crops allow for the use of more benign herbicides. Traditional herbicides such as atrazine and 2,4 D are narrowly targeted and persistent compounds (Paoletti, 1996). Farmers can now use broad spectrum Roundup herbicide, which has lower toxicity and “rapidly dissipates in water and soil” (Council for Agricultural Science and Technology, 2003). Therefore, any herbicide that enters the soil or water supply will safely disintegrate without harming the ecosystem.
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Herbicide resistant crops indirectly affect air quality by making no-till farming a more appealing option for farmers. Since less soil is disturbed with conservative till farming, organic matter is able to build-up in the soil and store carbon dioxide. In traditional agriculture, plowing exposes organic matter to oxygen. Oxygen then decomposes the organic compounds, releasing carbon dioxide into the atmosphere (Council for Biotechnology Information, 2003). The use of GM crops in no-till farming, however, enables the soil to sequester carbon dioxide. In effect, GMOs indirectly reduces the amount of this greenhouse gases released into the environment (DOE Consortium, 2002).
How do GM Crops Require Less Natural Resources?
Land
Genetic modification has important implications for the conservation of land. With estimates that there will be an increased demand for food in the next century, farmers must decide how they will meet that need without compromising the environment. Currently, the developing world is losing 4000-19,000 square miles of land a year to agriculture. With the use of GM crops, farmers can increase the yield of maize, cotton, and soybeans by 5-8% Greater land productivity through the use of GM crops will be a way for farmers to cultivate crops with minimal destruction of natural habitats (Panos Briefing, 1999).
Soil
Through the practice of no-till farming, farmers are able to preserve soil nutrients and prevent erosion. As a result, less arable soil is disrupted in the process. Estimates show that nutrients retained through no-till farming saves approximately 1 billion tons of soil a year (Consevation Technology Information Center, 2002).
Fuel
Less fuel is utilized in GM farming since the number of times tractors and planes are needed to spray herbicides is minimized. According to one study, 309 millions gallons of fuel is saved with no-till farming (Conservation Technology Information Center, 2002).
Water
Conservation tillage helps retain soil moisture. Approximately 70% of the freshwater used by humans each year goes toward agriculture. Since water is such a vital resource, being able to maintain as much moisture in soil as possible is beneficial to the environment (Conservation Technology Information Center, 2002).
How do GM Crops Increase Biodiversity?
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Recent evidence has shown that the improvement of the environment due to GM crops has led to an increase in biodiversity.
Better access to food
No-till farming, made possible by herbicide resistant crops, enables birds and mammals to obtain food more easily than in ploughed lands. Tilled land plows under important organisms that birds and other wildlife feed on to survive. Furthermore, plowed lands tend to have overgrowths of weeds that make it difficult for animals to forage. In traditional till fields, it takes an average quail 4.2 hours to feed. No-till farms only require the bird a fifth of the amount of time to eat. Additionally, it has been found that there are three to six time more earthworms in no-till land than in plowed lands. Therefore, farms using GM crops bring more wildlife to farms than traditional farms (Conservation Technology Information Center, 2002).
Improved habitats
Herbicide tolerant plants have also improved biodiversity by creating cleaner water supplies and overall improved habitats. One United Kingdom demonstrated an increase in “endangered wildlife and birds such as skylarks and finches” (Council for Biotechnology Information, 2003) in land that used GM crops. Another study found that fields using GM crops was especially appealing to bare-ground feeders such as doves and quails (Vincent, 2003). The ability of GM crops to improve habitats increases biodiversity.
For more information on ways GMOs can improve the environment, click here.
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This website was created by
Kevin Saunders, Helen Nguyen, and Chris Wrobleski
as part of an undergraduate assignment at Davidson College.
Send questions or comments to chwrobleski@davidson.edu.
© Copyright 2004 Department of Biology, Davidson College, Davidson, NC 28035.