MDARD Michigan Core Pesticide Applicator Practice Exam

Which soil condition is least likely to promote pesticide leaching?

1. Poorly drained soil

2. Deep soil

3. Shallow soil

4. Drought-prone soil

The correct answer is: Deep soil

Deep soil is the condition least likely to promote pesticide leaching because it provides a greater volume of soil to retain and filter water and chemicals. In a deep soil profile, there is more organic matter and clay that can absorb and bind pesticides. Additionally, deeper soils can have more water-holding capacity, which reduces the potential for rapid runoff and leaching of pesticides into groundwater. In contrast, shallow soils can lead to quicker transport of pesticides to underlying water sources due to less material to filter through. Similarly, poorly drained soils retain water and can create conditions where pesticides are more likely to move with water. Drought-prone soils may lack moisture, which can reduce leaching but also limits the transport of pesticides vertically. Therefore, the presence of deeper soil enhances the capacity for pesticide retention and reduces the risk of leaching.