Which term refers to the movement of pesticides through soil to groundwater?

Leaching refers to the process by which pesticides and other chemicals are carried through the soil and into groundwater due to the movement of water. When it rains or when irrigation occurs, water can dissolve and transport pesticide residues that have been applied to soil, allowing them to seep deeper into the ground. This is significant because it can lead to contamination of groundwater sources, which are vital for drinking water and irrigation. Understanding leaching is crucial for responsible pesticide management, as it helps applicators make informed decisions on pesticide usage and application timing to minimize environmental risks.

In contrast, drift refers to the airborne movement of pesticides away from the target area during or after application, while runoff involves the surface movement of water carrying pesticides away from the application site into nearby water bodies. Absorption refers to the process in which plants or soil take up pesticides, but it does not involve the movement to groundwater. Each of these terms represents a different mechanism by which pesticides can move through the environment, making it essential to differentiate them in the context of pesticide safety and environmental stewardship.