地表UV-B辐射增强对土壤-冬小麦系统呼吸速率和N2O排放的影响

通过室外盆栽实验,用静态箱-气相色谱法测定土壤-冬小麦系统的呼吸速率和N₂O排放通量,研究了UV-B辐射增强20%对土壤-冬小麦系统的呼吸速率和N₂O排放的影响.结果表明,相同的气象条件和田间管理下,UV-B辐射增强处理对呼吸速率和N₂O排放的季节变化模式无明显影响.在返青期,UV-B辐射增强显著降低了土壤-冬小麦系统的呼吸速率,但对N₂O的排放通量没有产生显著影响;在拔节孕穗期,UV-B辐射增强处理显著降低了土壤-冬小麦系统的呼吸速率和N₂O的排放通量;在抽穗-成熟期,UV-B辐射增强处理对土壤-冬小麦系统的呼吸速率和N₂O的排放没有显著影响.返青-齐穗期,UV-B增强处理显著降低土壤-冬小麦系统的N₂O累积排放量;但从齐穗开始至小麦成熟,UV-B增强处理对土壤-冬小麦系统的N₂O累积排放量没有显著影响.

Influence of Enhanced UV-B Radiation on Respiration Rate and N2O Emission from Soil-Winter Wheat System

To investigate the impact of enhanced UV-B radiation on respiration rate and N₂O emission from soil-winter wheat system, outdoor pot experiments with simulating 20% supplemental of UV-B were conducted, and static dark chamber\|gas chromatograph method were used. Results indicated that the enhanced UV-B radiation did not change the seasonal pattern of respiration rate and N₂O emission. Enhanced UV-B radiation declined the rate of soil-winter wheat system's respiration but had no significant impact on N₂O emission in turning-green stage. While enhanced UV-B radiation declined both respiration rate and the N₂O emission in elongation-pregnant stage. From heading to maturity, the respiration rate and N₂O emission from soil-winter wheat system were not found to be significantly difference under UV-B radiation compared with ambient conditions. A further analysis suggested that enhanced UV-B radiation declined significantly cumulative amount of N₂O from soil-winter wheat system from wheat turning green to full heading stage, while no significant impact occurred from full heading to maturity.