Field experiments were conducted during the 2007 to 2008 winter wheat-growing season to investigate the influence of enhanced UV-B radiation on diurnal variations in soil CO2 fluxes and nitrous oxide (N2O) emissions from a winter wheat ecosystem. CO2 and N2O fluxes were measured by static opaque chamber-gas chromatograph technique. Results showed that on sunny days, soil CO2 fluxes and N2O emissions from the soil-wheat system exhibited obvious diurnal variation patterns, which enhanced UV-B radiation. During the jointing, booting, and heading stages, enhanced UV-B radiation significantly decreased the mean diurnal CO2 fluxes of the soil by 49.62% (p = 0.000), 50.39% (p = 0.004) and 51.44% (p = 0.022), respectively. Enhanced UV-B radiation also reduced the mean diurnal N2O fluxes (MNF) of the soil-wheat system by 48.35% (p = 0.017) and soil MNF by 36.87% (p = 0.027) during the grain-filling stage. Our findings suggested that enhanced UV-B radiation did not change the diurnal variation patterns of soil CO2 fluxes and N2O emissions from the soil-wheat system, but influenced mean diurnal CO2 and N2O fluxes.
Journal articles from the Grassland Society of Southern Africa (GSSA) African Journal of Range and Forage Science as well as related articles and reports from throughout the southern African region.