Parameter Tree:
EARTH SCIENCE > AGRICULTURE > SOILS > CATION EXCHANGE CAPACITY

Definition:
The sum of exchangeable bases plus total soil acidity at a specific pH
value, usually 7.0 or 8.0. When acidity is expressed as salt extractable
acidity, the cation exchange capacity (CEC) is called the effective
cation exchange capacity (ECEC) because this is considered to be the CEC of the
exchanger at the native pH value. It is usually expressed in centimoles of
charge per kilogram of exchanger or millimoles of charge per kilogram of
exchanger


Reference:
Jackson, J.A. (1997) Glossary of Geology. 4th ed. Alexandria,
VA:American Geolog cal Institute. 769 p.