Which condition increases the potential for pesticide leaching?

Rainfall increases the potential for pesticide leaching because it provides the moisture necessary for the pesticides to move through the soil. When it rains, especially if there is heavy precipitation, water can percolate through the soil profile and carry dissolved pesticides with it. This process can lead to pesticides reaching groundwater or contaminating nearby water bodies, particularly if the soil is highly permeable or not adequately managed.

Leaching is influenced by several factors such as soil type, moisture content, and pesticide properties. In well-drained sandy soils, rainfall can accelerate leaching compared to heavier clay soils, where water moves more slowly. Therefore, adequate moisture from rainfall can significantly impact the distribution of pesticides within the soil and their potential to move beyond the target area.