Plant nutrient contents and spatial distribution patterns of toxic element concentrations in mine site soils

Abstract

: Open-pit coal mining causes land and soil degradation and negatively affects soil properties. It is of great importance to determine variabilities in soil properties of the abandoned area after the mine is closed and to bring it back to nature by implementing appropriate rehabilitation programs. The aim of this study was to evaluate plant nutrient availability and toxic element pollution in an abandoned coal mine site. The results indicated that the amounts of plant-available P and K are quite low (<90 kg P 2 O 5 ha –1 ) and low to moderate (<170 kg K 2 O ha –1 ), respectively. The concentrations of plant available Fe (>4.5 mg kg –1 ) and Cu (>0.2 mg kg –1 ) are too high in the whole study site. Soils in the study area generally have low organic matter content with ranging from 0.42% to 3.67%. Toxic element concentrations, especially Ni (>75 mg kg –1 ) and Cr (>100 mg kg –1 ), are extremely above the optimum levels, posing a great risk in the open-pit area (abandoned), the dump sites and the coal storage area.