As you begin to prepare your fields for this growing season, make the necessary steps to ensure herbicides stay out of surface and groundwater. The following field practices recommended by Michigan State University Extension can effectively reduce pesticide runoff, leaching and protect groundwater and surface water.
- Consider the geology of your area. When planning herbicide applications, be aware of the water table depth and the permeability of the geological layers between the surface soil and groundwater.
- Consider soil and field characteristics. Determine the susceptibility of the soil or field site to leaching or runoff. Soil texture and organic matter content, in particular, influence chemical movement into groundwater. The slope of the field also influences surface runoff.
- Reduce compaction. Surface water runoff increases when soils are compacted.
- Utilize conservation practices that reduce erosion and surface runoff. These practices include but are not limited to no-till and other forms of conservation tillage, increasing crop residues, planting cover crops, planting grass waterways to retard soil and water runoff, and keeping buffer strips to protect surface water boundaries. Recent research suggests some conservation practices increase soluble phosphorus leaching, so in areas where this is a problem, use management practices that will not cause nutrient leaching.
- Use integrated pest management programs. Minimize herbicide use by combining chemical control with other pest management practices such as tillage, cultivation, crop rotation and pest scouting.
- Rotate crops. Crop rotation can improve water infiltration, which reduces runoff. Crop rotations may also provide more surface crop residue and may reduce the need for applications of specific pesticides repeatedly to a given field site.
By using these basic principles, you can minimize the environmental impact on water quality by keeping herbicides out of the waters of the state. Remember that the label is the law, so before you do any pesticide application, read the label and follow the guidelines stated.
It is very difficult to clean contaminated groundwater or surface water. Treatment is complicated, time consuming, expensive and often not feasible. The best solution to groundwater and surface water contamination is to prevent the problem.