What is meant by runoff in relation to pesticides?

Runoff in relation to pesticides refers to the movement of water and other materials over the soil's surface. When it rains or when irrigation occurs, water can carry away pesticides that have been applied to the soil, leading to potential contamination of nearby water bodies. This process is significant because it can affect water quality and ecosystem health, making it crucial for pesticide applicators to consider how to minimize runoff when planning their applications. Understanding this concept helps in implementing best management practices to protect our water resources while effectively using pesticides.