Short-term effects of tillage and compaction on nitrous oxide, nitric oxide, nitrogen dioxide, methane and carbon dioxide fluxes from grassland

Abstract

N2O, NO, NO2, CO2 and CH4 fluxes were measured simultaneously from tilled and compacted soil in a factorial design to investigate the effect of management on trace gas emissions. Six treatments in combinations of with and without N application, tillage and compaction were investigated for a period of 3 weeks using the closed-chamber technique (for N2O, CO2 and CH4) and the open-chamber technique (for NO and NO2). Total NO emissions from the tilled plots were 2.4 times greater than from the non-tilled plots, whereas CO2 emissions were 1.8 times greater from the non-tilled plots. Compaction increased the emissions of N2O and CH4 3.5- and 4.4-fold, respectively, compared with emissions from uncompacted plots. The effects of tillage and compaction on the gaseous emissions are discussed in relation to their production, transport and lifetime within the soil. The results showed that the best option for reducing gaseous emission from fertilised soil, with regards to tillage or compaction, would be the least compacted system, regardless of the tillage status as reflected, at least in the short term, by minimal emissions of N2O and CH4 and to some extent those of NO, NO2 and CO2.