Impact of Opencast Mining on Soil Physico-Chemical Properties -- A Case Study from Bansra OCP of Raniganj Coalfield.

Coal mining activities affect the soil by causing soil erosion, formation of sinkholes, and leaching chemicals into the soil. The overburden dumps deposited in un-mined areas create mine spoils causing various environmental problems. Present study compared soil physico-chemical properties from an open cast coal mine of Raniganj (Bansra OCP) and a protected forest Ballavpur Wildlife Sanctuary (BWS) to investigate the effects of open cast coal mining on soil quality. Layer wise (0-10, 10-20 and 20-30 cm) soil samples were collected from 0-, 4-, 7- and 26-year old overburden dumps of Bansra OCP and also from BWS. Layer wise, no significant variations were observed in soil properties. ANOVA indicated significant variations in soil properties among overburden dumps and forest. Soil pH, calcium, sodium, magnesium and electrical conductivity were higher in overburden dumps than in the forest. These cations showed 51 to 91% increase in overburden dumps compared to the forest soil. Mining activity altered the soil quality due to decline in organic carbon, available nitrogen, potassium and phosphorus in the young aged overburden dumps. With the increase in the age of overburden dumps, significant recovery in organic carbon, mineral nitrogen and magnesium was observed, while pH, moisture, calcium and sodium declined significantly. No significant increase was observed in soil potassium and phosphorus, while clay and silt contents remained lower in all the overburden dumps. [ABSTRACT FROM AUTHOR]