Compared to sandy soil, water in clay soil tends to move?

• A. more vertically
• B. more horizontally
• C. not at all
• D. only downward

Answer: (B)

Water movement in soil follows hydraulic gradients, and texture largely controls how easily water can move. In sandy soil, the big pore spaces let water drain quickly under gravity, so vertical movement is fast. In clay, the tiny pores create strong capillary forces but very low overall permeability, so water moves much more slowly and tends to redistribute within the soil layer rather than draining straight downward. As a result, moisture tends to spread out horizontally, especially when there’s a slope or uneven moisture, making horizontal movement more pronounced in clay than in sand. The water is still moving, but the slower vertical drainage in clay makes lateral redistribution the dominant pattern compared to sandy soil.