How does clay content influence cation exchange capacity (CEC)?

Clay content significantly influences cation exchange capacity (CEC) due to the inherent properties of clay particles. Clay soil is composed of very small, negatively charged particles that have a high surface area. As clay content increases, so does the potential for these negative charges to attract and hold positively charged ions (cations) such as calcium, magnesium, potassium, and sodium in the soil.

This means that soils with a higher clay content typically have a higher CEC, allowing them to hold more nutrients, which is beneficial for plant growth. The capacity to retain cations is essential for maintaining soil fertility, as it helps in the exchange of nutrients available to plants. Therefore, an increase in clay content is directly related to an increase in CEC, making it a critical factor in understanding soil chemistry and fertility management.