MDARD Michigan Core Pesticide Applicator Practice Exam

How does strong adsorption affect pesticide movement?

1. It increases the likelihood of leaching

2. It reduces the likelihood of surface runoff and leaching

3. It has no effect on movement

4. It only affects plant absorption

The correct answer is: It reduces the likelihood of surface runoff and leaching

Strong adsorption refers to the process by which pesticide molecules bind tightly to soil particles. This phenomenon is significant because it affects the behavior and mobility of pesticides in the environment. When pesticides strongly adsorb to the soil, they are less likely to be washed away by water movement, leading to a reduction in surface runoff. This means that rainfall or irrigation does not easily carry the pesticide off the field into nearby water bodies, which is crucial for minimizing water contamination. Additionally, strong adsorption also means that the pesticide is held tightly within the soil matrix, making it less available for leaching, which is the downward movement of dissolved substances through the soil profile into groundwater. This is particularly important for protecting groundwater supplies from pesticide contamination. In summary, strong adsorption stabilizes pesticides in the soil, effectively reducing their mobility and potential for impacting surrounding environments, thereby decreasing both surface runoff and leaching potential.