The term “exchangeable bases” or “total exchangeable bases” refers to the sum of the concentration of the bases (calcium, magnesium, potassium, and sodium) in exchangeable form. Exchangeable cations are those that can be replaced by a cation from an added salt solution. The minerals present in the soils govern the dominance of exchangeable bases. As for exchangeable bases, cation exchange capacity (CEC) is a fundamental soil property for assessing soil fertility, as it represents the capacity of soils to adsorb, retain and exchange cations, which are the main soil nutrients. CEC is affected by pH, thus it depends on the organic matter content and other soil components (e.g. clay mineralogy).

• SOP for cation exchange capacity and exchangeable bases 1N ammonium acetate, pH 7.0 method