Iowa Pesticide Applicator Practice Exam

Which factor influences the movement of pesticides through leaching into groundwater?

1. Wind speed

2. Soil characteristics

3. Temperature

4. Pesticide color

The correct answer is: Soil characteristics

Soil characteristics play a crucial role in the movement of pesticides through leaching into groundwater. The texture, structure, and composition of the soil influence how easily water and dissolved substances, including pesticides, can move through the soil profile. For example, sandy soils tend to allow quicker water movement and can lead to greater leaching of pesticides compared to clay soils, which are more compact and can retain water and chemicals for longer periods. Organic matter content is also significant, as it can bind pesticides, reducing their mobility. Thus, understanding the properties of the soil is essential in assessing the potential for pesticide leaching into groundwater. Other factors, while they may have some indirect effects on pesticide behavior, do not directly impact the leaching process as fundamentally as soil characteristics do.