Soil Health & Amendments

What is cation exchange capacity and why does it matter?

CEC is a measure of the soil's ability to hold positive nutrient ions (calcium, magnesium, potassium, ammonium). Higher CEC = more nutrient-holding capacity = more fertile soil. Sandy soils typically have CEC of 1-5; loamy soils 5-15; clay-rich and high-organic soils 15-30+. Low CEC soils need more frequent fertilization in smaller doses.