Cation Exchange Capacity

Cation exchange capacity (CEC) is a fundamental soil property that measures the soil's ability to hold and release positively charged nutrient ions (cations: K⁺, Ca²⁺, Mg²⁺, Na⁺, H⁺, Al³⁺) in forms available to plant roots. CEC reflects the amount and type of clay minerals and organic matter in the soil—compounds with negatively charged surface sites that attract and temporarily bind cations. High CEC soils retain nutrients longer and require less frequent fertilization; low CEC soils lose nutrients rapidly through leaching.