What is “pesticide runoff”?

Pesticide runoff refers specifically to the movement of pesticides from their intended application site into nearby water bodies, such as rivers, lakes, or streams. This phenomenon typically occurs when rainfall or irrigation causes excess water to flow over the land, carrying along with it the pesticides that have been applied to the soil or plants. Understanding pesticide runoff is crucial for environmental protection, as it can lead to water contamination, affecting aquatic ecosystems and potentially entering drinking water supplies.

The other choices describe different processes related to pesticides but do not accurately capture the essence of runoff. Absorption into the soil is a part of pesticide behavior but focuses on retention rather than movement. Pesticide degradation discusses how pesticides break down over time, which is essential for understanding persistence and environmental impact but does not relate directly to the transport of pesticides. Accumulation of pesticides in plants indicates a different interaction where plants uptake pesticides rather than depicting their movement into water bodies. Thus, the correct choice highlights the critical environmental concern of pesticides leaving the application area and impacting water quality.