SPATIAL VARIABILITY OF CADMIUM, PH, ORGANIC-MATTER IN SOIL AND ITS DEPENDENCE ON SAMPLING SCALES

Distribution of cadmium, pH(K Cl), and organic carbon content in the s oil over a 29-ha field was evaluated. Cadmium concentrations were foun d mostly within the interval 0.17-1.27 ppm, with increasing trend towa rds one edge of the field. Cadmium concentrations were correlated with pH and organic carbon content. A one-hectare section of the original area was selected to analyze spatial variability of cadmium, pH and or ganic carbon content using geostatistical techniques. Cadmium concentr ations were found to be spatially dependent and anisotropic, whereas p H levels did not reveal space dependence. Similar spatial behaviour of cadmium and organic carbon was observed. Linear correlation analysis at the one-hectare section revealed strong correlation between organic carbon and Cd, whereas no coincidence between Cd and pH was found. Ex tensive application of a cadmium-contaminate sludge in the past is sug gested as a possible cause of this phenomenon.