What effect does adding compost have on cation exchange capacity?

Adding compost to soil typically increases the cation exchange capacity (CEC). Cation exchange capacity refers to the soil's ability to hold and exchange positively charged ions (cations) such as calcium, magnesium, potassium, and sodium. Compost is rich in organic matter, and this organic material enhances the soil structure by creating more micropores, which can hold water and nutrients better.

As organic matter decomposes, it contributes to the formation of humus, a stable form of organic matter that has a high ability to attract and hold onto cations. This characteristic means that soils with higher organic matter content, such as those amended with compost, can retain more nutrients, making them more fertile and better able to supply plants with the necessary nutrients they need for growth.

In contrast, options indicating that compost either decreases CEC or has no impact are not consistent with the understanding of how organic matter contributes to soil's nutritional and physical properties. Similarly, suggesting that compost alters soil texture completely overlooks the role of texture in soil structure, as compost primarily influences the soil’s organic matter content rather than completely changing its texture.