Differential responses of the soil nutrient status, biomass production, and nutrient uptake for three plant species to organic amendments of placer gold mine-tailing soils

Surface mining activities usually devastate the landscape, rendering it unsuitable for plant growth. Organic amendments have been widely applied for the restoration of soil nutrients as well as the soil structure in mine tailings. However, the responses of growth and nutrient uptake among plant species to organic amendments have not been well evaluated. In this study, we conducted a pot experiment to examine the impacts of peat and cattle manure amendments on the total soil C, N, P, K, Ca, and Mg; the available soil P, K, Ca, and Mg; and the growth and nutrient concentrations of re-established Mongolian pine (Pinus sylvestris var. mongolica), lespedeza (Lespedeza daurica), and lyme grass (Elymus dahuricus) in the Guliku placer gold mine area in northeastern China. Organic amendments, especially cattle manure, improved the soil nutrient status and availability compared with those in nonamended mine soils. The plant biomass and nutrients of the 3 species were altered differently by the 2 amendments. Although peat addition increased the total soil C, total N, and available Ca, it had little impact on plant biomass production due to a lesser increase in available soil P, K, and Mg and a decrease in total soil K. Our results highlight that both balanced increase in soil nutrients by applying appropriate soil amendments and the selection of suitable plant species are necessary for the successful reclamation of postmined lands.