Acid oxalate reagent was used at various concentrations, pH values, shaking times, and soil to solution ratios to find the optimum conditions for the extraction of Al, Fe, and Si from short‐range‐order materials in soils and stream‐bed deposits. The optimum conditions vary with the nature of the soil sample and its components. For most soils maximum amounts of Al, Fe, and Si were extracted with 0.15M acid oxalate reagent at pH 3.0 with a soil to solution ratio of 1:100 and shaking for 4 h in the dark at 20°C. Soils with more than 5% oxalate‐extractable Al or Fe require a 0.20M oxalate solution at pH 3.0 with a soil to solution ratio of 1:200.