In uncropped soil, copper was the least effective in changing the activity of arylsulfatase and acid phosphatase.
All of the tested enzymes were less resistant to copper contamination in cropped than in uncropped soil. In soil planted with oat, β-glucosidase was the most resistant and arylsulfatase was the least resistant enzyme to copper contamination. In samples sown with spring rape, the analogous enzymes were arylsulfatase and alkaline phosphatase. In yellow lupine treatments, alkaline phosphatase was the most and β-glucosidase was the
least resistant enzyme.