Vegetation response to lime and manure compost amendments on acid lead/zinc mine tailings: A greenhouse study

Land disturbed by mining in China is a serious problem and lead/zinc (Pb/Zn) mine tailings constitute the majority of the metal mine tailings produced in Guangdaong Province, China. A greenhouse study was therefore conducted to evaluate the effects of lime (40, 80, 120, and 160 t/ha) and manure compost (50 and 100 t/ha) amendment on the revegetation of the Pb/Zn mine tailings using Cynodon dactylon (Bermuda grass) and Agropyron elongatum (tall wheatgrass). The results showed that a combination of lime and manure compost amendment together with deionized water leachating was able to increase pH, reduce electrical conductivity and diethylenetraminepentaacetic acid (DTPA)-extractable concentrations of Zn and Pb in tailings. Using greater than or equal to 80 t/ha lime amendment with the supplement of fertilizer or manure compost was able to effectively improve germination of both C. dactylon and A. elongatum. The highest dry weight yields were obtained in tailings receiving greater than or equal to 80 t lime/ha and 100 t manure compost/ha for both plant species. Plant tissue analysis showed that lime amendment at 120-160 t/ha reduced Zn accumulation in both shoot and root of C. dactylon. However, this trend was not observed for Pb.