Quantification of greenhouse gas emissions from managed biofuel plantations in a semi-arid landscape of Southern India

Abstract

Jatropha curcas L. and Pongamia pinnata (L.) Pierre, are promising biofuel species in peninsular India. We quantified greenhouse gas fluxes from managed 9 year old plantations of these species for all seasons in three consecutive years (2012–2013, 2013–2014 and 2014–2015) using manually-operated closed chamber method. CH4, N2O and CO2 were analysed by using Varian 450-GC based on Gas Chromotography. The mean soil CO2, CH4, and N2O emissions in the Jatropha curcas plantation recorded were 7.720 t ha−1 y−1, 0.023 t ha−1 y−1 and 0.017 t ha−1 y−1, respectively. While in Pongamia pinnata soil CO2, CH4, and N2O emissions were recorded to be 7.633 t ha−1 y−1, 0.008 t ha−1 y−1 and 0.019 t ha−1 y−1, respectively. Our results indicate that Jatropha curcas has higher GHG emissions than Pongamia pinnata. A pronounced seasonal variability was observed in CH4, N2O and CO2 flux rates. The highest emissions for Jatropha curcas occur during rainy season, whereas for Pongamia pinnata it occurs during winter. Soil moisture and temperature being the most influencing factors for CO2 fluxes from soil. We conclude that these plantation has an effect on soil-atmosphere GHG exchanges and can act as a good source of mitigation of greenhouse gases.