This method is similar to 15B1 except that there is a pre-treatment with aqueous ethanol and aqueous glycerol to remove soluble salts.
60% Aqueous Ethanol (w/w)
As for Method 15A2.
20% Aqueous Glycerol
As for Method 15A2.
Other Reagents
As for Method 15A1.
Follow the 60% Aqueous Ethanol – 20% Aqueous Glycerol wash procedure given for Method 15A2. When completed, transfer the pretreated soil plus about 4 g Acid-washed Sand to the plastic extraction container. Proceed as described in Method 15B1 but make allowance for entrained aqueous solvent as described in Method 15A2.
Determine and report exchangeable cations and CEC (cmolc/kg), expressed on an oven-dry soil basis as for Method 15B1. Refer to Method 2A1 for guidance with regard to this soil moisture calculation.