CARBON SEQUESTRATION IN RECLAIMED MINED SOILS OF OHIO

Abstract

This research project is aimed at assessing the soil organic carbon (SOC) sequestration potential of reclaimed mine soils (RMS). Experimental sites characterized by distinct age chronosequences of reclaimed minesoil were identified. These sites are owned by Americal Electrical Power and are located in Guernsey, Morgan, Noble, and Muskingum Counties of Ohio. The sites chosen were: (1) reclaimed without topsoil application (three under forest and three under continuous grass cover), (2) reclaimed with topsoil application (three under forest and three under continuous grass cover) and (3) unmined sites (one under forest and another grass cover). Soil samples were collected from 0 to 15 cm and 15 to 30 cm depths from each of the experimental site under continuous grass and SOC and, total nitrogen (TN) concentration, pH and electrical conductivity (EC) were determined. The results of the study for the quarter (30 September to 31 December, 2003) showed that soil pH was > 5.5 and EC < 4 dS m{sup -1} for all sites and depths and therefore favorable for grass growth. Among the three reclamation treatments, SOC concentration increased from 1.9 g kg{sup -1} for site reclaimed in 2003 (newly reclaimed and at baseline) to 11.64 g kg{sup -1} for site reclaimed in 1987 (a 5-fold increase) to 20.41 g kg{sup -1} for sites reclaimed in 1978 (a 10- fold increase). However, for sites reclaimed without topsoil application, soil pH, EC, SOC and TN concentrations were similar for both depths. The SOC concentrations in reclaimed sites with topsoil application in 0 to 15 cm depth increased from a base value of 0.7 g kg{sup -1} at the rate of 0.76 g kg{sup -1} yr{sup -1}. The high SOC concentration for 0-15 cm layer for site reclaimed in 1978 showed the high carbon sequestration potential upon reclamation and establishment of the grass cover on minesoils.