Effect of moisture content and preparation technique on the composition of soil solution obtained by centrifugation

Wetting up either air‐dried or field moist soil to predetermined moisture contents resulted in substantial changes in the composition of soil solution. Solute concentrations were generally reduced following a 24‐hour equilibration period. The magnitude of these changes was dependent upon the amount of water added and the element involved. Air‐drying soil for 14 days at 25°C resulted in increased concentrations of most determined elements upon rewetting. Both physical and chemical changes in the soil occurred during the sample preparation and the centrifugation process. Soil solution should be separated from field moist soil as quickly as possible after sample collection.