STUDIES ON SOIL COPPER I. THE FRACTIONATION OF COPPER IN SOILS

Abstract

Summary A method for fractionating soil copper was developed and applied to 24 soils representing a range of British soil types. The scheme distinguishes five fractions: soil solution and exchangeable copper; copper weakly bound to specific sites; organically bound copper; copper occluded by oxide material; and residual copper mainly in clay lattice structures. Correlation and regression analyses confirmed the general validity of the scheme and indicated an association between free manganese oxides and copper which considerably influences the distribution of copper between the main soil constituents. It is suggested that the concentration of copper in the soil solution is controlled by equilibria involving specifically adsorbed copper and that the bulk of the‘available’soil copper reserves reside in the organically bound fraction.