Greenhouse Gas Emissions following Conversion of a Reclaimed Minesoil to Bioenergy Crop Production

Abstract

This study provides a comparative assessment of greenhouse gas (GHG) emissions when converting a reclaimed minesoil that was previously under meadow to miscanthus (Miscanthus × giganteus) and maize (Zea mays L.) land uses in Ohio, USA. Additionally, effluent from an anaerobic digester at rates of 0, 75, 150, and 225 kg N ha−1 rates was also assessed for C and nutrient fertilization. Results from the study show that land use conversion to maize had the highest net release of GHG equivalent of 6·6 Mg CO2equ ha−1 y−1, on average, across effluent application rates. Under miscanthus land use with no and high effluent application rates, net GHG equivalent on average was 4·3 Mg CO2equ ha−1 y−1, which was larger when compared with that under the meadow land use (1·6 Mg CO2equ ha−1 y−1). Miscanthus land use under medium rates of effluent application had similar net GHG equivalent (7·1 Mg CO2equ ha−1 y−1) to the maize land use. The application of effluent did increase CO2–C and N2O–N emissions; but increases in above‐ground–below‐ground biomass production (1·6 Mg C ha−1) in the meadow land use and C input from effluent retained in the soil in the miscanthus and maize land uses offset most of the effluent‐induced GHG equivalent emissions. Contribution of cumulative N2O–N to GHG equivalent emissions in general was 11% when no effluent was applied and 22% when effluent was applied across land uses. Findings from this study show that land use changes from antecedent meadow to maize and miscanthus during the first year of establishment would result in net increase of GHG emissions. Published 2017. This article is a U.S. Government work and is in the public domain in the USA

Real‐time monitoring of greenhouse gas emissions with tall chambers reveals diurnal N2O variation and increased emissions of CO2and N2O fromMiscanthusfollowing compost addition

“…2000 µg m −2 hr −1 , which is more than ten times the magnitude of fluxes reported from Miscanthus in a long‐term study at this site (Drewer et al, ) and approximately half the maximum rate seen at this farm following the addition of 120 kg N/ha ammonium nitrate fertilizer to oilseed rape (OSR, Brassica napus L.; Keane et al, ). While fluxes of a similar magnitude have been reported from unfertilized Miscanthus elsewhere (Guzman, Ussiri, & Lal, ), N 2 O emissions from established Miscanthus plantations are widely thought to be much lower than those from conventional cropping (McCalmont, Hastings, et al, ).…”