Abstract:

The research aim was to understand the influence of revegetation of mining wasteland at gold-copper mine on soil physical and chemical properties, soil moisture content, aggregate structure, nutrient, heavy metal content and soil erosion were measured at 4 different revegetation stages of mining wasteland by the vegetation governance mode of Pinus massoniana +Lespedeza bicolor+Vetiveria zizanioides+local beach turf at Zijinshan gold-copper mine in Fujian Province, by using the method of substituting spatial difference for time change. The results showed that soil moisture content reduced in the first year of revegetation, then increased gradually with time, being close to the control after 5 years. The soil total N, available-N, total K and organic matter content were increased gradually with time and exceeded the soil nutrient critical value, but they were less than the control after 5 years. Soil total and available-P initially increased and then decreased with recovery time. After initially increasing and then decreasing, the water stability of soil aggregates increased, apart from particles with diameter 0.25-0.5 mm and there was no significant difference to the control after 5 years. The soil heavy metal content showed a similar pattern over time and the total content of Zn, Cu, Cd and Ni were 2.7, 5.6, 1.2 and 1.2 times respectively, that of control after 5 years. Soil total Cu, Pb, Zn, Mn, Cr and Ni content did not exceed the China National Soil Environment Quality Standard (level Ⅲ) after 5 years, apart from Cd. Soil erosion decreased gradually with increased recovery time, and there was no significant difference to the control after 5 years. The results indicated that Pinus massoniana +Lespedeza bicolor+Vetiveria zizanioides+local beach turf was better allocation mode to the soil quality restoration of the wasteland at Zijinshan gold-copper mine.