Use of cation/anion exchange membranes for multi-element testing of acidic soils

We have developed a technique using cation/anion exchange resins which allows the simultaneous extraction from soil of Ca, Mg, K, Mn, Al and P. Ions are extracted by shaking soil with resin in distilled water. The resin is separated from the soil and ions are desorbed from the resin using an acid/salt solution. Concentrations of ions in solution are then determined by conventional means. Concentrations of ions extracted by the resin method were compared with concentrations determined by commonly-used analytical procedures. Except for Al, concentrations of ions extracted by the resin procedures correlated well with conventional extraction and analytical procedures. The resin membrane method offers considerable speed and cost advantages over conventional methods.