Which soil texture has the lowest hydraulic conductivity?

Which soil texture has the lowest hydraulic conductivity?

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

Answer: (C)

Hydraulic conductivity measures how easily water can move through soil, and it depends on pore size and how well those pores are connected. Large, well-connected pores in coarse textures let water flow quickly, giving high conductivity. Clay has very small pores, and it tends to swell, which reduces pore connectivity and creates many obstacles for flow. That combination makes water move through clay very slowly, so it has the lowest hydraulic conductivity. By comparison, gravel and sand have large pores and high conductivity, while silt is intermediate.

Hydraulic conductivity measures how easily water can move through soil, and it depends on pore size and how well those pores are connected. Large, well-connected pores in coarse textures let water flow quickly, giving high conductivity. Clay has very small pores, and it tends to swell, which reduces pore connectivity and creates many obstacles for flow. That combination makes water move through clay very slowly, so it has the lowest hydraulic conductivity. By comparison, gravel and sand have large pores and high conductivity, while silt is intermediate.