Which statement best describes the function of a wetting agent in soils?

• A. Increases drainage.
• B. Improves water penetration in hydrophobic soils and reduces runoff.
• C. Raises soil pH.
• D. Decreases soil moisture retention.

Answer: (B)

Wetting agents act like surfactants for water: they lower the water’s surface tension so it spreads and soaks into soils that resist wetting. In soils that have become hydrophobic, water tends to bead up and flow across the surface instead of soaking in. By reducing this resistance, the wetting agent improves water infiltration, allowing irrigation or rainfall to penetrate more evenly and reducing surface runoff. That’s why this option best fits what wetting agents do.

They don’t primarily raise soil pH, so that isn’t their main purpose. They also aren’t meant to decrease soil moisture retention; rather, they help water move into the soil more effectively, which can improve overall moisture availability when used correctly.