Twenty soils were extracted in duplicate with 1 M KC1 and analysed for Al by AAS, ICPES, double titration and an eriochrome cyanine R colorimetric method. Exchange acidity was also measured and compared with Al values. Differences between the four Al methods were small. The only statistically significant difference was that Al by ICPES exceeded Al by AAS and titration. Results by the colorimetric method did not differ from those by the other three. Exchange acidity values were higher than Al by titration, with differences ranging from 0.07 to 1.01 m. equiv. 100 g‐1. There was close agreement between ICPES and AAS results for both calcium and magnesium in the KC1 extracts. It was concluded that Al, Ca and Mg in KC1 extracts can be measured by any of the analytical procedures tested but a distinction should be made between exchange acidity and exchangeable Al.

Cation exchange capacity of ten non‐calcareous and non‐saline soils from Queensland, Australia, has been determined by the ammonium acetate method using different procedures, by an ammonium chloride method at pH8.5, and by three methods which attempt to approximate field conditions. Procedural differences in the ammonium acetate method produced variation in results, and methods using approximate field conditions gave much lower values for those soils considered to have variable charge properties. Key words: CECMethods