SOIL CHEMICAL PROPERTIES OF OPENCAST COAL MINING SITE IN INDONESIA AND ITS EFFECT ON PLANT GROWTHDewi Wulandari, Saridi, Doddy Herika, Cahyono Agus, Weiguo Cheng and Keitaro TawarayaAbstract Opencast coal mining causes severe ecosystem disturbances, such as soil degradation, excessive waste production, overburden formation, and possibly reforestation inhibition. In this study, we assessed the effect of opencast coal mining on soil chemical properties and plant growth in soil from natural forests and post coal mining sites (a 16-year-old coal mining site in Lati and a 5-year-old coal mining site in Sambarata) in Berau Regency, East Kalimantan, Indonesia. Soil pH, total carbon, total nitrogen, available phosphate, exchangeable cations, and cation exchange capacity were measured. Plant growth and shoot phosphorus, potassium, calcium, magnesium, and iron concentrations were determined as well. Soil from the post coal mining sites had lower pH, total carbon, total nitrogen, available phosphate, potassium, sodium, calcium, magnesium, and cation exchange capacity than soil from the natural forests. Reduction of shoot nutrient content and plant biomass was observed in Sorghum bicolor grown in soil from both Lati and Sambarata post coal mining sites. By calculating the correlation between soil chemical properties and plant growth, it was found that all the soil chemical properties are limiting factors of plant growth in Lati. The results revealed that opencast coal mining reduced soil fertility and inhibited plant growth, which hinders successful reforestation. Thus, monitoring, evaluation, and restoration of post coal mining area is recommended to prevent more severe environmental damage. |