
Pesticides are chemicals used to protect crops such as potatoes against pests that mainly include insects, weeds, and fungi. Correct application of these chemicals plays a key role in food production. If pests are present in the field and pesticides are not applied, crop yields may significantly drop below profitable levels. This makes pesticide application necessary.
Pesticides may have to be applied a few times per growing season on the same crop field. Each pesticide has its own chemical properties and may interact with plants, pests, soil, water, and other organisms differently. Pesticide application in crop fields has the potential to contaminate water drainages. This is exacerbated by the fact that most fields are often prepared for good drainage. In irrigated farmland, the water quantity applied could easily be controlled to prevent run-off. The problem with potential water contamination may occur in rainfed crops where excessive rainfall is experienced beyond what existing soils may hold. This may result in a situation where pesticides and/or their residues get transported into groundwater and/or freshwater supplies. Water contamination from pesticides is also enhanced by the solubility of these chemicals in the water. As a preventive measure, farmers often rely on the local weather forecast to determine when pesticide spraying should or should not happen. However, not all regions have access to reliable rainfall prediction information. In such regions, farmers may take the risk and apply pesticides without any consequences, even if contamination eventually occurs.
Some pesticides and their residues may be retained in soils for several years. Most of these types have been banned in notable developed countries, but their use continues in most developing countries. The likelihood of contamination from such pesticides in developing countries is only made worse by the fact that these countries also tend to have unreliable rainfall prediction information. In some of these countries where prediction is reliable, information on safe pesticide application may not even reach the farmer. Some governments in developing countries have mechanisms where extension officers are sent to train farmers, but officers report poor attendance due to a lack of farmer incentives.
The risk of drinking water that is contaminated with pesticides mainly lies with humans that get water from private water wells. Farmers happen to be among this group of people in most cases due to the remoteness of agricultural land where pesticide application prevails. Water in private wells may be tested from time to time, but this operation is usually more voluntary than mandatory in most countries.
Humans may be affected by pesticides in many ways. Some pesticides, if ingested, affect the nervous and hormonal systems. Others may cause cancer or irritate skin/eyes. There is a lot of on-going research related to reducing the risk of pesticide contamination. These include but are not limited to 1) limiting application to times when excessive rainfall is envisioned following spray day, 2) reducing pesticide quantities applied by spot spraying, and 3) using pesticides that have less mobile active ingredients.
My research focuses on reducing quantities applied by spot spraying only in regions where pests prevail. Even under spot spraying, the need to only apply pesticides when weather conditions are suitable should not be underemphasized. Furthermore, spot spraying must be carried out at recommended application rates. I believe that my research will largely contribute to contamination reduction and enhance both human and environmental protection.
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