Which soil type has the fastest water movement?

• A. Clay soil
• B. Loamy soil
• C. Sandy soil
• D. Silty soil

Answer: (C)

Water movement through soil is controlled by permeability, which depends on pore size and how well those pores are connected. Coarse-textured soils with larger, well-connected pores allow water to flow with much less resistance, so they drain and infiltrate quickly. Among common soils, sandy soil has the largest pore spaces and highest hydraulic conductivity, enabling rapid water movement downward and through the profile. In contrast, clay soil has very small, plate-like particles that create tiny pores and strong water attraction to surfaces, which greatly slows movement and promotes water retention. Silty soils have smaller pores than sand but larger than clay, giving an intermediate rate of flow, while loamy soils mix textures and typically show moderate, steady movement. So, the fastest water movement occurs in sandy soil.