Behavior Of Phosphate In Soil Extracts Using Weak Unbuffered Extracting Solutions

Phosphate concentrations in extracts of soil samples using unbuffered 0.01 M calcium chloride (CaCl2) decreased in time, especially in extracts of calcareous soil samples due to phosphate adsorption on walls of tubes and flasks. To overcome these changes in time, extracts were immediately after centrifugation or filtration acidified to pH 2.0 using hydrochloric acid (HCl).