How does soil texture affect cation exchange capacity (CEC)?

Cation exchange capacity (CEC) is a critical property of soil that refers to the soil's ability to hold and exchange positively charged ions, or cations, such as calcium, magnesium, potassium, and sodium. Soil texture plays a significant role in determining CEC due to the size and surface area of the soil particles.

Finer textured soils, such as clay, have a larger surface area relative to their volume compared to coarser textured soils like sand. This greater surface area provides more sites for cation adsorption. Clay particles, in particular, have a negative charge that attracts and holds cations, enhancing the soil's ability to retain essential nutrients and making them available to plants. As a result, finer textures, by virtue of their particle size and charge characteristics, lead to increased CEC.

In contrast, coarser textured soils, which contain larger particles such as sand, have less surface area and fewer charged sites for cation binding, resulting in lower CEC. The statement regarding texture having no effect on CEC overlooks the fundamental relationship between surface area, particle size, and nutrient exchange capacity. While organic matter does influence CEC, it operates alongside soil texture rather than replacing it as a determinant. Thus, the relationship established between