Iowa Pesticide Applicator Practice Exam

In the context of pesticides, what does “adsorption” refer to?

1. The attachment of pesticide molecules to soil particles

2. The vaporization of pesticides into the air

3. The solubility of pesticides in water

4. The breakdown of pesticides over time

The correct answer is: The attachment of pesticide molecules to soil particles

Adsorption refers specifically to the process where pesticide molecules adhere to the surfaces of soil particles. This interaction can significantly influence the availability and movement of pesticides in the environment, impacting how effectively they work against pests, as well as their potential for leaching into groundwater or runoff into surface water. When pesticides adsorb to soil, it can help in prolonging their activity by reducing their mobility, though it can also limit their effectiveness if too much is adsorbed and they cannot reach the target organisms. The other options describe different processes related to pesticides. Vaporization involves the transformation of liquid pesticide into gas, which can affect how pesticides disperse in the environment but does not involve surface attachment. Solubility in water refers to how readily a pesticide dissolves in water, affecting its efficacy and movement through soil but not its adherence to soil particles. The breakdown of pesticides over time involves degradation or metabolism, which influences their longevity in the environment but does not pertain to the attachment process defined in adsorption.