N2O and CH4 emissions from bare soil and a bioenergy crop cultivation on a peat extraction site

摘要

This paper reports chamber measurements of nitrous oxide (N2O) and methane (CH4) from a cutaway peatland cultivated with reed canary grass (Phalaris arundinacea L.) (RCG) and an adjacent peat extraction (PE) sites made during growing seasons in 2004-2007.Seasonal N2O emission varied between 0.031 and 0.118 g N2O m~(-2) at the RCG site and 0.001 and 0.015 g N2O m~(-2) at the PE site.Seasonal CH4 emissions varied between 0.08 and 0.48 g CH4 m~(-2) in RCG site and 0.06 and 1.05 g CH4 m~(-2) in PE site.Low N2O emission levels in the case of RCG were attributable to the lower amount of N-fertilizer,no-till cultivation practice,low nitrification activity and effective use of nitrogen by RCG.Low methane emissions were associated with the low water table level.These results indicate that methane and N2O emissions from the studied peat extraction site are negligible and as such they have a minor role in the overall greenhouse gas balance and production chain of RCG as a bioenergy crop.