What can be added to raise the CEC of soil?

To raise the cation exchange capacity (CEC) of soil, adding organic matter or clay is the most effective choice. CEC is a crucial property of soil that indicates its ability to hold and exchange essential nutrients. Organic matter, such as decomposed plant material, contributes to CEC because it contains many functional groups that can retain cations. Furthermore, clay particles have a high surface area and a negative charge, allowing them to effectively hold onto positively charged ions (cations) such as calcium, magnesium, and potassium.

In contrast, sand primarily consists of larger particles with low surface area and limited ability to hold nutrients, thus not enhancing CEC effectively. Water alone does not influence the CEC because it does not add any new capacity for nutrient exchange to the soil. Adding only minerals can change soil composition but does not inherently increase CEC unless those minerals are rich in clay or organic material.

This understanding of CEC is essential for effective soil management and fertility practices. By integrating organic matter or clay into the soil, you can significantly improve the nutrient-holding capacity, leading to healthier plants and more successful agricultural practices.