Analysis of water soluble Copper residue in the top soils of some Cocoa growing areas of the Central Region of Ghana

Abstract

Water soluble copper concentrations in some topsoil samples collected between February and March 2000 from eleven cocoa growing towns in the central Region of Ghana were determined. In all a total of hundred and eighty soil samples were taken randomly at a depth of 0-20cm from preselected farms. copper fungicides were applied in ten of the farms and the eleventh farm which served as a control had no fungicide application. Some physical and chemical properties of the soils were determined. Analysis for copper was done using atomic absorption spectrometer after the extraction process. Water-soluble copper in the soils ranged from 0.05 to 0.40mg kg-1 with a mean concentration of 0.265 mg kg -1.The correlation was done to determine the factors responsible for the differences in the absorption levels of water-soluble copper. Water soluble copper correlated negatively and insignificantly (P>0.5) with cation exchange capacity, organic carbon, available phosphorus, nitrogen, moisture, and silt while an insignificant (P>0.05) positive correlation existed between copper level and pH of the soil. Also a significant (P<0.05) negative moderate correlation existed between water soluble copper concentration and soil clay content while a significant (P<0.05) positive correlation existed between copper concentration and sand content of the soil