Which property of a pesticide would make it more likely to move with water in surface runoff?

• A. Low volatility
• B. Low solubility
• C. High adsorption to soil
• D. High solubility

Answer: (D)

Movement with surface water depends on how well the pesticide dissolves in water. A pesticide with high solubility dissolves readily in rainwater or irrigation water, so it stays in the dissolved phase as runoff travels across the field. That makes it more mobile and likely to be transported with the water to surface waters or drains. In contrast, pesticides that don’t dissolve well (low solubility) or that strongly adsorb to soil particles tend to stay attached to the soil or stay in the soil solution less, making them less likely to ride along with runoff. So the best answer is the property of high solubility.