A comparison of extraction and suspension methods for determining exchangeable potassium in soils

Comparative studies of extraction–suspension methods for the determination by AAS of exchangeable potassium suspensions (0.1% m/v) of finely ground soil using a variety of extractants (neutral 1 M ammonium acetate, 1 M ammonium chloride, 1.26 M strontium chloride and 0.1 M hydrochloric acid) were performed. The quantification of exchangeable potassium by neutral 1 M ammonium acetate measured by each method produced a significant correlation and a close agreement was found at a confidence level of 95%.