This Standard specifies a method for the determination of pH in a 1 M KCl soil suspension and where required titratable actual acidity (TAA) in acid sulfate soil.

NOTES:

1 The TAA measurement does not quantitatively recover retained acidity held in iron and aluminium hydroxy-sulfate minerals, such as jarosite, KFe₃(SO₄)₂(OH)₆ and similar minerals. Methods to determine the retained acidity are given in AS 4969.6 and AS 4969.11.

2 The suspension from this method can be analysed subsequently to determine KCl extractable sulfur, calcium and magnesium (AS 4969.4).