Exchangeable base cations (1993-2002)

Exchangeable magnesium (mmol_c / kg dry matter, extractant: 1N NH₄OAc solution, buffered to pH 7.0)
Exchangeable calcium (mmol_c / kg dry matter, extractant: 1N NH₄OAc solution, buffered to pH 7.0)
Exchangeable potassium (mmol_c / kg dry matter, extractant: 1N NH₄OAc solution, buffered to pH 7.0)
Exchangeable sodium (mmol_c / kg dry matter, extractant: 1N NH₄OAc solution, buffered to pH 7.0)