Water pollution caused by agricultural practices is an increasingly alarming problem around the world. As the global demand for food continues to rise, more farmers are turning to pesticides and fertilizers to sustain and maximize output. The upshot of these practices, however, is the contamination of groundwater and surface water that negatively impacts lives and ecosystems.
Pesticides and Fertilizer: Friends or Foes?
The practice of using pesticides and fertilizers comes with a particular challenge that largely contributes to agricultural water pollution. As it is hard to gauge the ideal amount of pesticide and fertilizer for a given plant, farmers spray their crops liberally because they believe spraying more is preferable to spraying less. This causes excess chemicals from pesticides and fertilizers to either seep deep into the ground and into groundwater or be carried off by rain into other surface water—streams, rivers, lakes, and oceans.
Groundwater is especially important as a source of drinking water internationally. According to a report done by the United Nations Educational, Scientific, and Cultural Organization (UNESCO), roughly 2.5 billion people around the world rely on groundwater as their source of drinking water. In the U.S. alone, 40 percent of people rely on groundwater for drinking water, especially in rural areas where it is often the only source of drinking water for entire communities.
In addition to the health risks posed by groundwater, surface water contamination has similarly pernicious effects. As chemical contaminants from pesticides and fertilizers find their way into surface water, land and aquatic plants and animals are becoming ill or dying off. The threat of surface water contamination is especially well understood through the process of biomagnification. As people eat contaminated plants and animals, they too consume and ingest the chemicals; consequently, water contamination upsets entire ecosystems and the food chain.
With the effects water pollution has on people and ecosystems, water pollution caused by agricultural practices calls for urgent measures. In order to effectively apply a solution, it is essential to recognize where efforts would best be targeted. In the case of water pollution caused by agricultural practices, there is evidence to suggest that it is most effective to simultaneously clean up contaminated water and prevent chemical contamination in the first place. Part of this stems from the unfortunate reality that it is tremendously difficult to clean up contaminated water, given how quickly contaminants disperse when in the substance. For this reason, according to the Natural Resources Defense Council (NRDC), polluted groundwater aquifers alone, can be “unusable for decades, or even thousands of years.”
In addition to acknowledging the difficulty of cleaning up polluted water, it is important to recognize which particular contaminants have especially negative global effects. The Food and Agriculture Organization of the United Nations (FAO) argues that nitrate is among the worst. Nitrate comes from nitrogen, the main ingredient in fertilizers, implying that fertilizers, more so than pesticides, are one of the world’s greatest sources of water pollution. Although nitrates are vital for proper plant growth, they can be “dangerous for humans in large amounts.”
Despite high amounts of nitrate dangerously affecting people’s health, the FAO claims that use of global nitrogen fertilizer is expected to grow in coming years with the rising demand for food, particularly in Sub-Saharan Africa, East and South Asia, and North America. Now, more than ever, it is pertinent to look for solutions that allow farmers to use fertilizers in more environmentally friendly ways.
Farmers and scientists in Nebraska’s Platte River Valley appear to have found an answer. Looking at their example might provide a better sense of what farmers around the world can do to prevent nitrate water pollution.
Case Study: Water Pollution in Nebraska’s Platte River Valley
Nebraska’s Platte River Valley is well-known for contributing to the state’s booming agricultural business. Right behind California, Texas, and Iowa, Nebraska ranks fourth in overall agricultural output in the United States. This success can partly be attributed to the valley’s nutrient rich-soil. As the Platte River runs its course, minerals are deposited into the surrounding ground. Farmers in Nebraska’s Platte River Valley take advantage of this natural fertilizer to sustain their agricultural practices.
However, the global demand for food is pressuring Nebraskan farmers to increase their crop yield, and consequently, to change their strategies. As such, from the later half of the 20th century and into the modern era, they have begun to couple the river’s natural fertilizer with chemical fertilizers. The effects of chemical fertilizer use have been similar to the effects seen around the world: nitrate water pollution.
While the Platte River aids Nebraska’s farmers, it also restricts the type of crops they can grow. Given the high amount of groundwater in the valley, deep-root plants are best suited to survive and thrive in the area. Thus, corn and soybeans are Nebraska’s main crops. These deep-rooted plants can withstand being swept by the unstable soil underneath them. Chemical fertilizers, on the other hand, lack the structural capacity to do the same. Instead, excess fertilizer seeps into the groundwater and drains into local streams and rivers. Hence, Nebraskan farmers are facing more nitrate in their drinking water.
The legal limit for nitrate in public water systems is 10 parts per million (ppm); in Nebraska, the levels are two to three times higher than that. Feeling personally responsible for Nebraska’s problem with nitrate water pollution, farmer Ken Seim and others are turning to precision technology to help prevent nitrate run-off.
The name of this precision technology is “Project Sense.” It was created by researchers from the University of Nebraska and relies on sensors to measure just the right amount of fertilizer a plant needs. According to the website Flatland, “Farmers would apply fertilizer evenly and generously across their fields. Some farmers figured that if some nitrogen fertilizer was good for their plants, more was better. That meant that some plants would get more than they could use, which left nitrates [leaching] into groundwater.” Project Sense prevents excess nitrate runoff. As the machine rolls through fields, its sensors measure the size and color of the plants. Based on this data, the machine is able to gauge how much fertilizer a plant needs, and then delivers the correct dosage.
Farmers like Seim have noticed less nitrate runoff from their farms; however, there is no existing research that investigates the potential long-term effect of using precision technology to solve nitrate water pollution on a larger scale. Part of this stems from how expensive the technology is, which makes it infeasible for enough farmers to use this technology in order to be able to do a proper study.
For farmers who cannot afford Project Sense, other options exist. Researchers from the University of Nebraska recommend cover crops as another method of mitigating nitrate water pollution. Cover crops are off-season crops, planted after main crops have already been harvested. They help fight soil erosion and maintain soil fertility, with the added benefit of retaining moisture and nitrate runoff.
Current Policies and Potential Solutions
Governments and international organizations around the world can also step up to the plate and fund research that helps tackle the global problem of nitrate water pollution. As of now, government farm subsidies around the world are used to control the cost and supply of crops, not agricultural practices. They are rarely used as investments in new research and technology that can help make agricultural practices more environmentally friendly. This makes it difficult for farmers to afford stopping environmentally damaging practices. Furthermore, lack of global legislation mandating farmers to institute environmentally friendly practices makes it even less likely that problems like nitrate water pollution will be sufficiently dealt with any time soon. As of now, such initiatives remain largely voluntary.
In the United States, for example, no laws mandate farmers to incorporate precision technology nor cover crops. Thus, as a 2010 report by the U.S. Department of Agriculture shows, areas particularly likely to be responsible for significant nitrate water pollution (Corn Belt) are also just as likely to not be applying methods to mitigate this problem.
In the developing countries of Africa and Asia, there are few, if any, policies mandating environmentally friendly agricultural practices; furthermore, poverty makes it difficult for farmers in developing countries to implement environmentally friendly agricultural practices. Such circumstances only exacerbate the problem of global nitrate water pollution.
Overall, evidence shows that the best way to mitigate the problem of global nitrate water pollution is to prevent it from happening in the first place. In order for that to happen, however, a balance between precision technology, government subsidies for research and farm technology, and laws mandating the implementation of environmentally friendly agricultural practices must exist. Otherwise, nitrate water pollution will continue to poison water systems, thereby disrupting people’s lives and ecosystems. As global fertilizer use is projected to grow, it is crucial that people around the world unite in collective action to help prevent further nitrate water pollution.
