The results show that the pH values of Cu tailings amended with manure compost (CuM) or sewage sludge (CuS) were significantly lower (p ⩽ 0.05) than those of Cu tailings (Cu) ( Table 5). However, the EC values of tailings amended with manure compost (CuM) or sewage sludge (CuS) were significantly higher (p ⩽ 0.05) than that of the control tailings (Cu) according to the increase in application rates. There was also marked improvement in nutrient conditions, with substantial increases in organic carbon, total N and P, and water-soluble N and P according to the increase in application rates, except water-soluble P in the sewage sludge treatment ( Table 6). In general, the concentrations of the DTPA-extractable Cu, Zn, and Pb of the tailings that received manure compost or sewage sludge, with or without fertilizer, were significantly lower (p ⩽ 0.05) than those of the control tailings (Cu), except for Cu content in CuM10 and CuS10 ( Table 5), but concentrations of DTPA-extractable Zn in these substrata were significantly higher (p ⩽ 0.05) than those of the control tailings (Cu).