Soils with higher organic matter content hold more water and adsorb more pesticides than soils with lower organic matter content.

• A. Less
• B. The same amount of
• C. Varies with weather
• D. More

Answer: (D)

Higher organic matter in soil provides more sites and a favorable structure for holding water and for sorbing chemicals. The organic matrix creates a network of pore spaces and contains humic substances that trap and retain water, increasing the soil’s water-holding capacity. It also offers numerous adsorption sites and functional groups that interact with pesticides, especially hydrophobic ones, so more pesticide molecules are retained rather than moving with water. Because of these effects, soils rich in organic matter can store more water and adsorb more pesticides than soils with less organic matter. Weather can affect actual moisture levels on a given day, but the inherent capacity itself is higher with more organic matter, making the “More” choice the best fit.