Which soil texture typically retains the most water?

• A. Sand
• B. Clay
• C. Silt
• D. Loam

Answer: (B)

Understanding how soil texture affects water retention helps explain why clay holds the most water. Clay particles are the smallest, creating a lot of tiny pore spaces and a large surface area. Water sticks to these surfaces and is held in the tiny pores by capillary and adsorption forces, so the soil can store a large volume of water overall. However, this also means drainage is slow and some of that water is held quite tightly and isn’t readily available to plants. In comparison, sandy soils have larger gaps between particles, so water drains away quickly and doesn’t stay around; silt holds more water than sand but less than clay; loam mixes textures to provide good balance, typically retaining more than sand or silt but not as much as pure clay.