Which soil texture has the lowest hydraulic conductivity among the following?

Which soil texture has the lowest hydraulic conductivity among the following?

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

Answer: (D)

Water movement through soil slows as pore sizes get smaller; hydraulic conductivity is a measure of how easily water moves when the soil is saturated. Clay has the smallest pores and the tendency to swell, which narrows pathways and makes water flow very difficult. That combination gives the lowest saturated hydraulic conductivity among the textures listed. Sand has large, well-connected pores that allow water to move quickly, so its conductivity is high. Silt is intermediate, and peat can be variable due to its organic structure and macropores, but it doesn’t typically exceed clay in restricting flow.

Water movement through soil slows as pore sizes get smaller; hydraulic conductivity is a measure of how easily water moves when the soil is saturated. Clay has the smallest pores and the tendency to swell, which narrows pathways and makes water flow very difficult. That combination gives the lowest saturated hydraulic conductivity among the textures listed. Sand has large, well-connected pores that allow water to move quickly, so its conductivity is high. Silt is intermediate, and peat can be variable due to its organic structure and macropores, but it doesn’t typically exceed clay in restricting flow.