Which factor influences Cation Exchange Capacity (CEC) in soil?

Cation Exchange Capacity (CEC) refers to the ability of soil to hold and exchange positively charged ions (cations) such as calcium, magnesium, potassium, and sodium. A critical aspect of CEC is how it is influenced by both soil texture and organic matter content.

Soil texture, which is determined by the relative proportions of sand, silt, and clay particles, plays a vital role in CEC. Clay particles have a high surface area and a negative charge, which allows them to attract and hold cations effectively. Thus, soils that are high in clay content typically exhibit higher CEC compared to sandy soils, which have less surface area and fewer negatively charged sites for cation retention.

Organic matter content is another essential factor for CEC. Organic matter contributes to the negative charge and increases the cation-holding capacity of the soil. As organic matter decomposes, it forms humus, which further enhances the soil’s ability to retain nutrients. Soils rich in organic matter can significantly improve nutrient availability for plants.

Therefore, both soil texture and organic matter content are key factors influencing CEC in soil, making the combination of these two critical for understanding nutrient management in agricultural practices.