Soil Organic Carbon Content in Reclaimed of Ex-Coal Mined Land on 7-year-old Sengon (Paraserianthes falcataria) Stands

Abstract

Coal-mined lands tend to have low soil organic carbon content. Revegetation activities allow the natural process of carbon sequestration by plants to occur, thus increasing organic carbon content. This study aimed to estimate organic carbon content and storage, to analyze the soil changes of soil properties and to determine the correlation between soil organic carbon and other soil characteristics on coal-mined land. Soil sampling was conducted in reclaimed coal-mined land on 7-year-old Sengon (Paraserianthes falcataria) at PT Ratu Samban Mining, Bengkulu Province at depths of 0-10 cm, 10-20 cm, and 20-30 cm. Soil samples taken at each depth were tested for organic carbon content, pH, field capacity, bulk density, and soil texture (percentage of sand, clay, and silt). The statistical analyses used were ANNOVA, LSD, regression, and correlation. The results showed different organic carbon contents at depths of 0-10 cm, 10-20 cm, and 20-30 cm of 1.67%; 1.34%; and 1.00%, respectively. Bulk density had significant negative correlation with soil organic carbon with a significance value of 0.021 (p<0.05) and a correlation coefficient (r) of -0.653. Reclamation activities through revegetation for 7 years have caused carbon absorption into the soil but it were still low.