Rethinking Pesticide Use in Agriculture Practices
Hannah Wigginton
Bio410, Senior Seminar
November 30, 2007
Thesis:
Due to ecological problems including pesticide resistance, pesticide-induced pests, and escalating costs of pesticides, it is more beneficial for environmental sustainability and community development to consume a diet largely of local, pesticide free foods through alternative farming techniques rather than relying on conventional agriculture.
Americans have been using pesticides since Europeans relocated in the United States and began cultivating the land. The use of these chemicals has risen greatly in the last century, however, and many times they are implemented quickly and used without assessing the potential ecological damages beforehand. Pesticides in conventional agriculture create a number of ecological problems including pesticide resistance and pesticide-induced pests, environmental risks such as runoff of chemicals into wetlands, and escalating costs along with fewer discoveries of pesticides. For these reasons it is more beneficial for environmental sustainability and community development to consume a diet largely of local, pesticide free foods through alternative farming techniques rather than relying on conventional agriculture.
The reason behind the state of conventional agriculture today and why food relies on so much on pesticides, large machinery, and shipping long distances, is because of how agriculture has evolved. Wessel’s Living History Farm (2005) goes into detail about the history of agriculture in the United States. In the 1930s, farmers began specializing more and more in certain crops. These miles and miles of uninterrupted fields of one monoculture provide ideal feeding conditions for pests (para. 5). Large industrial farms also greatly limit the ratio of hedgerows, or woody areas, to fields and this is another contribution to the large amounts of pests. These hedgerows that are rapidly diminishing are important ecosystems for pest predators between fields and roads or lawns, and even weeds in between rows of crops (Altieri, 1994, p. 110). These reasons, as well as technological advances in agriculture, are just some of the motives for the growing increase in demand for pesticides in the United States today.
Although humans have been using pesticides even before 500 B.C. when farmers put elements such as sulfur on their crops, the application of pesticides has substantially increased today (Wessels para. 7). Beginning in 1400 A.D., farmers used different arsenic products as the main pesticide for their crops. The biggest leap forward for pest control happened in 1939 when the Swiss chemist Paul Muller discovered the chemical Dichloro-Diphenyl-Trichloroethane, or DDT (National Research Council [NRC], 1996). During World War II, DDT was largely responsible for the proportionally low numbers of deaths from diseases compared to previous wars. After WWII was over, the new chemical age began and by 1952, almost 10,000 new pesticide products were registered with the USDA. Pesticide use today has increased 50-fold, and pesticides are on average more than 100 times more toxic than the 1950s. (Miller, 2005, p. 520)
A new wave of environmentalism came in 1962 when Rachel Carson published her book, Silent Spring, which raised people’s awareness of the topic of pesticide overuse. Before Carson’s message, environmentalists were largely concerned with loss of forests and wildlife. With the publishing of Silent Spring, people started paying more attention to the agricultural issues and concerns contributing to environmental degradation and human health (Carson, 1962). This shift was evident when the Environmental Protection Agency was established in 1970, and almost immediately began banning a variety of pesticides that are more dangerous and last the longest in the environment. Although 45 years have passed since Carson’s book was first published, agricultural production is still headed down a path of increased pesticide use and it is going to take a lot to turn around this movement.
There are several problems with pesticides in conventional agriculture today, and perhaps the most convincing controversy is one of pesticide resistance. Within 5-10 years of first usage, pests commonly become resistant to pesticides, meaning they develop an ability to withstand increasing concentrations of applied chemicals. When this happens, farmers have to spend more money in order to spray increasing amounts of pesticides on their fields, creating what is called a pesticide treadmill. This resistance keeps building in the pests until there must be switch to a new, often more expensive chemical, and the process begins anew (NRC, 1996 p. 28).
Pesticides can also have harmful effects on beneficial or non-target species they come in contact with. This is why pesticides are more correctly called biocides. Pesticide implies that only the pest is being killed, when in reality a number of other living things die along with the pest. Many times these species killed are beneficial and help with the biological control of pests. Once farmers spray their fields with chemicals, they create what are called pesticide-induced pest problems. In fact, G. Tyler Miller explains that of the 300 most destructive insect pests in U.S., 100 were once minor pests that became major after insecticides (Miller, 2005 p. 523). One classic example of this common problem as described by the National Research Council is the elevation of the citrus red mite from a minor or non-pest status to a very harmful citrus pest in California after the introduction of chlorinated hydrocarbon and organophosphate pesticides (NRC, 1996 p. 50). Similar patterns can be seen worldwide as nature adapts to manmade chemicals and come back in pest outbreaks that were not anticipated or predicted.
It is a common misconception that once a pest becomes resistant to a pesticide, other chemicals can be substituted over and over as long as is needed. This trend is tricky because the cost of new agricultural chemicals has increased dramatically since 1956. In fact, according to the American Crop Protection Association, about 12% of the proceeds from agricultural sales in the U.S. go to research and development of new chemicals. The total is about $650 million, and even after all of this investment the probability that the product will be successful is declining. Since 1970, the number of new pesticides has been steadily declining and consequently development costs are increasing (NRC, 1996, p. 28-29). Based on this information it will be imperative that a new alternative to pesticide use becomes prevalent to use less money on a problem that is only aggravating itself.
Pesticide use also creates large environmental risks for all farmers and ecosystems, not only the ones that use them regularly. Since all ecosystems are interconnected and pesticides take anywhere from several hours to 15 years to decompose, their threats can stretch a long way and harm many environmental systems. According to the United States Department of Agriculture, only about 0.1-2% of pesticide spray reaches the target species (as cited in Miller, 2005, p. 523). This unleashes anywhere from 98-99.9% of the chemicals into wetlands, bodies of wildlife, and other ecological niches. Here, some pesticides accumulate in the food chain, and all of them cause environmental damages.
One classic example that Rachel Carson brought to the public’s attention with her book is the chemical DDT, which is harmful for many reasons. DDT is a broad-spectrum chemical and kills beneficial insects along with pests. It also stays in one chemical form for up to 15 years, which is a lot longer that most, if not all, other chemical (Miller, 2005, p. 520). The use of DDT was banned in the United States by the EPA in 1975, as well as mercuric compounds in 1976, and dibromochoropropane in 1977 (NRC,1996, p. 39). Carson also claimed that DDT harmed the bird population, honey bees, and can cause cancer in humans (Carson, 1962). Since Silent Spring there has been an ongoing debate of whether or not these last few things are accurate as there is no conclusive evidence for DDT directly harming human health.
Despite all these negative views of pesticides it is still a fact that they are beneficial to human society in several ways. There is little debate that pesticides can save lives when used on killing malaria-causing mosquitoes, and they are beneficial in terms of supplying enough food for high crop yields. There is also a large debate as to whether or not they pose any health risks at all, at least in the United States. One argument for the use of pesticides by the UN Food and Agriculture Organization claims that “about 55% of the world’s potential human food supply is lost to pests – about two-thirds of that before harvest and the rest after” (Miller, 2005, p. 523). With the U.S. economy the way it is today, switching our conventional agricultural methods of using pesticides into a completely organic structure of agriculture would require much work.
There are other studies that say, however, that pesticides have not been as effective in reducing crop losses to pests in the United States as hoped, due to decreases in natural predators and genetic resistance. Miller discusses three major conclusions drawn by the insect ecologist David Pimantel, after evaluating data from 300 major agricultural and economic scientists. The first deduction was: "Although the use of synthetic pesticides has increased 33-fold since 1942, about 37% of the U.S. food supply is lost to pests today compared to 31% in the 1940’s. Since 1942, losses attributed to insects almost doubled from 7% to 13% despite a 19-fold increase in the use of synthetic insecticides" (as cited in Miller, 2005, p. 524-525). The second conclusion has to do with health, and the third one explains that alternative pest management practices could cut the use of chemical pesticides in half, if done in the right ways, on 40 major U.S. crops without reducing crop yields (Miller 2005).
With this being said, it is clear that pesticide-induced pest problems, pesticide resistance, higher costs for decreasing numbers of new pesticides developed, and environmental risks will continue to persist and create a larger predicament for generations to come as long as consumers keep buying and using pesticides. For this reason it is in the best interest for upcoming generations to ensure the availability of safe, profitable, and durable solutions to the pest problems of the future. The best way to implement these safer methods of unconventional agriculture is through ecologically based pest management, governmental subsidies, and broader education of all Americans about the problem.
Ecologically based pest management (EBPM), are practices that “promote the economic and environmental viability of agriculture by using knowledge of interactions between crops, pests, and naturally occurring pest-control organisms to modify cropping systems in ways that reduce damage associated with pests” (NRC, 1996, p. 3). These systems are different than the earlier methods called Integrated Pest Management (IPM). This method of pest control strives to control pests using some of the same principles as EBPM, however it is limited to pest scouting and precise applications of insecticides. For this reason EBPM is based on the improved knowledge of these ecosystem interactions.
Both EBPM and IPM are helpful in reducing the use of pesticides in U.S. agriculture and some of the implementations include cover crops, biological control of pests, crop rotation, and using more ecologically based treatment sprays such as Bacillus thuringiensis. Cover crops are noncrop plant species that are grown during the winter or when regular crops are not being grown. Some examples of cover crops are vetch and clover, which help manage pests as well as reintroduce nutrients, such as nitrogen, and help plants with nitrogen fixation, raise the level of organic soil matter, and reduce soil erosion (NRC, 1996, p. 45). These plants are then tilled up in the spring and can act as automatic mulching for the next crop that comes in. Cover crops can, however, remove nutrients from the soil and should therefore be monitored regularly and made sure they are being grown in appropriate locations.
Crop Rotation is also a very important part of EGPM and is an easy way to regularly monitor the different nutrients being added to the soil. The basic idea is that no one crop is put in the same soil from one year to the next, but instead plant components are chosen according to the crops nutritional contributions to the soil and the plants are rotated from year to year. In Miguel Altieri’s book Biodiversity and Pest Management in Agroecosystems, (1994) he explains crop rotation and other EGPM based strategies. With crop rotation there is increased control of weeds, and one example of its effectiveness can be seen with a weed common in corn plants called the corn rootworm. This weed consistently produces higher levels in a continuous corn monoculture than in corn fields rotated with soybean, clover, alfalfa, or other crops (p. 82). Growing alfalfa, for instance, also enhances the predators and parasites to insect ratio on the farm.
Other alternatives to encourage farmers to integrate EBPM into their farming practices are increasing governmental subsidies to these farmers. Catherine Badgley practices organic farming in Michigan, and she explains in an article in the Michigan Daily (2007) that the reality of low food costs from conventional agriculture is actually much more complex than it seems. She claims that agricultural subsidies costing taxpayers over $25 billion per year go to conventionally produced food. It has been explained that these methods of conventional agriculture escalate genetic resistance to pesticides, pesticide-induced pest problems, higher costs for decreasing pesticides, and many environmental risks including surface and groundwater contamination, contamination of wildlife, and increase greenhouse gas emissions. Taxpayers are paying to reverse the damage that they are contributing to, as well as research for the betterment of agriculture; most of which is also directed toward conventional agriculture. Thus Badgley explains, “we pay for conventional agriculture at many stages. In contrast, organic agriculture pays its own way” with higher prices to begin with (para. 11).
This phenomenon is hard for the average American to comprehend because we are so used to grocery stores and large farms with pesticides. In a book called Saving the Planet with Pesticides and Plastic, Dennis Avery (1995) further reinforces the reality that the U.S. government does not encourage alternatives to using large amounts of pesticides. Currently, the U.S. is encouraging farmers to spray their fields by receiving high subsidies if they obtain high yields. This practically forces farmers to use plenty of pesticides. Avery also says environmentalist have done little to encourage the government to change this policy and begin subsidizing non-conventional agriculture, which is a crucial step in order for farmers and consumers alike to want to develop more sustainable practices involving food production.
Education is the last step for everyone to understand his or her food. Since all Americans eat, they should all be informed about what they are eating and how it impacts the broader world around them. In a recent book entitled The Omnivore’s Dilemma, Michael Pollan (2007) traces the food on his plate back to its origins and talks about the shades of meaning behind the word organic. He discusses the organic, industrial, and personal food chains and the ecological, and political and ethical ties to them (para. 2). This kind of education is hard to get and may have to rely on picking and choosing information from fact and fiction. In the end, however, knowing where food comes from and what is in it makes for better community, health, and broader environment.
Most people in the U.S. are significantly distant from the processes of growing and raising food, and have no idea how it is handled. Carson helped point out some of the threats of pesticides 45 years ago. If we want to have a viable agricultural future for further generations it is in our best interest to at least consider these warnings. Pesticides now pose troubles like pesticide-induced pest problems, pesticide resistance, higher costs for a decreasing supply of new pesticides, and many environmental risks on top of these. The problems of pesticide use in agriculture are even more apparent than they were forty-five years ago, and there are several strategies to help people re-evaluate how food is grown. Some of these strategies include ecologically based pest management, governmental subsidies, and education of farmers and consumers about the reality of pesticides and their alternatives. Once these ideas and solutions become more widespread and popular there is hope that a new agricultural revolution is upon us. Can we make it happen?
Altieri, M. (1994). Biodiversity and Pest Management in Agroecosystems. Food Products Press: London.
Avery, Dennis (1995) Saving the Planet with Pesticides and Plastic. Hudson Institute: Indianapolis.
Badgley, Catherine. (2007, October 3). Harvest Time. Michigan Daily. Retrieved October 20, 2007, from http://media.www.michigandaily.com/media/storage/paper851/news/2007/10/03/TheStatement/Harvest.Time-3008029.shtml
Carson, Rachel. (1962) Silent Spring. New York: Houghton Mifflin Company.
Miller, G. Jr. (2005) Living in the Environment. Singapore: Thomson.
National Research Council. (1996). Ecologically Based Pest Management: New Solutions for a New Century. National Ecology Press: New York.
Pollan, Michael (2007) The Omnivore’s Dilemma: A Natural History of Four Meals, Website. Retrieved November 5, 2007 from http://michaelpollan.com/omnivore.php
Wessels Living History Farm. (2005) Farming in the 1930’s. Retrieved October 26, 2007 from http://www.livinghistoryfarm.org/index.html