Fertility Check Corner: Cation Exchange Capacity
Cation Exchange Capacity (CEC) is used as an indicator of soils’ potential to hold nutrients. To estimate CEC, laboratories use the following minerals: Hydrogen (H), Calcium (Ca), Magnesium (Mg), Potassium (K), and Sodium (Na). (Note: Sodium not used for CEC calculation in all regions.)
Soil particles are inherently negatively charged and are attracted to positively charged ions (cations). Soil texture has the greatest influence on soil CEC. The types of clay minerals in your soil will greatly influence the types and amounts of minerals absorbed. For example, soil with a low CEC (10-12 meq/100g) is a Sandy Loam and has low nutrient holding capacity. A soil with a high CEC (20-30+) is a Clay Loam and has a high nutrient holding capacity.
CEC is a useful tool for Nitrogen, Potassium, and Hydrogen (pH) management. SGS uses CEC to determine the amount of potassium needed to build soil K. For pH management, SGS uses CEC to determine the amount of lime needed to reduce the acidity of soil.
SGS offers CEC on your soil test with the Standard and Advanced package. Contact your local SGS Soil Testing Laboratory for more information.
Dr. Angela Guidry
Key Account Specialist
SGS is the world’s leading inspection, verification, testing and certification company. SGS is recognised as the global benchmark for quality and integrity. With more than 67 000 employees, SGS operates a network of over 1 250 offices and laboratories around the world.