[Impacts of elevated ozone concentration on N2O emission from arid farmland].

ABSTRACT

To investigate the impact of elevated surface ozone (O3) concentration on nitrous oxide (N2O) emission from arid farmland, field experiments were carried out during winter-wheat and soybean growing seasons under the condition of simulating O3 concentrations, including free air (CK), 100 nL x L(-1) O3 concentration (T1), and 150 nL x L(-1) O3 concentration (T2). N2O emission fluxes were measured by static dark chamber-gas chromatograph method. The results showed that the accumulative amount of N2O (AAN) were decreased by 37.8% (P = 0.000 ) and 8.8% (P = 0.903 ) under T1 and T2 treatments, respectively, in the turning-green stage of winter wheat. In the elongation-booting stage, ANN were decreased by 15.0% (P = 0.217) and 39.1% (P = 0.000) under T1 and T2 treatments, respectively. ANN were decreased by 18.9% (P = 0.138) and 25.6% (P = 0.000) under T1 and T2 treatments, respectively, during the whole winter-wheat growing season. No significant impact of elevated O3 concentration on N2O emission from soil-soybean system was found due to the less rainfall during the soybean growing season, drought had a stronger stress on soybean than O3 concentration. The results of this study suggested that elevated O3 concentration could reduce N2O emission from arid farmland.