Carbon Dioxide Emissions from Reclaimed Mine Soils in Eastern Ohio.
Raj K. Shrestha, The Ohio State Univ, School of Environment and Natural Resources, 2021 Coffey Rd, Columbus, OH 43210 and Rattan Lal, The Ohio State Univ, School of Environment and Natural Resources, 2021 Coffey Rd, Columbus, OH 43210.
Soil disturbances due to mining and post-reclamation land uses affect soil organic carbon (SOC) and green house gas (GHG) emissions. This study was conducted to study the effects of soil disturbances (drastically disturbed reclaimed coal mine, moderately disturbed agriculture, and undisturbed forest soil) and post-reclamation land uses (pasture, hay and forest) on carbon dioxide (CO2) emissions and its relationship with the physical and chemical properties of the soil. The soil air samples were collected biweekly from April 2005 to May 2006 using static chambers. Soil moisture was measured with a Time-domain reflectometer (TDR) and soil temperature with thermistors in conjunction with soil air sampling. Composite soil and core samples were collected for physical and chemical analyses to study relationships with CO2 emissions. Measurements of CO2 emissions made throughout a year indicated that high fluxes of CO2 were observed during April - June (0.42 to 9.36 g m-2 d-1), moderate during July - September (0.73 to 4.13 g m-2 d-1), and low during October - February (0.04 to 1.33 g m-2 d-1). The mean CO2 emissions were the highest from reclaimed mine soil (RMS) under pasture (3.87 g m-2 d-1) followed by agriculture (2.87 g m-2 d-1), RMS under hay (2.28 g m-2 d-1), RMS under forest (1.37 g m-2 d-1), and natural forest (1.07 g m-2 d-1). The CO2 fluxes were positively correlated with soil bulk density, cone index, silt content, SOC pool, nitrogen concentrations, and air and soil temperatures. The CO2 fluxes were negatively correlated with clay content, infiltration rate, pH, C:N ratio, and soil moisture.