Definitions for "Cation exchange capacity"
The sum total of exchangeable cations adsorbable by the porous medium; expressed in moles of ion charge per kilogram of porous media.
the capacity of a soil to adsorb cations; cations are adsorbed at exchange sites, and can be released in exchange for other cations.
Cation exchange capacity (CEC): a measurement of the capacity for soil particles to hold onto positively charged ions (cations) Cation exchange capacity is an important measurement of garden soils because it expresses the ability of the soil to hold onto nutrients (ions) with a positive charge like magnesium, potassium, hydrogen, calcium, copper, zinc, etc). The CEC is largely attributed to the clay content and the organic matter content of the soil. Each of these has the capacity to hold onto positively charged nutrients. Sandy soils have a low CEC while clay soils have a high CEC. The expression of CEC is typically given in milliequivalents (meq) per 100 grams of soil. Loamy soils range from 15 to 30 meq. It takes more lime to raise the pH of a clay soil (with more exchangeable sites for cations) than it does a sandy soil.