臭氧浓度升高对农田土壤呼吸、硝化及反硝化作用的影响

Effects of Elevated Ozone Concentration on Soil Respiration, Nitrification and Denitrification in a Farmland

自2010年春季,于南京信息工程大学农业气象试验站采用开顶式气室(OTC)大田试验,利用臭氧自动发生和调控系统模拟臭氧浓度升高环境,测定土壤呼吸速率、硝化与反硝化速率,同时观测土壤温度和土壤湿度,探讨臭氧浓度升高对冬小麦农田土壤呼吸、硝化及反硝化作用的影响。结果表明,臭氧浓度升高对冬小麦农田土壤呼吸速率的生育期内的变化规律无显著影响,但会降低冬小麦农田土壤呼吸,同时臭氧浓度升高会限制冬小麦农田土壤温度对土壤呼吸的影响,随着臭氧浓度升高,Q10值减小,降低了冬小麦农田土壤呼吸的温度敏感性,也会减小冬小麦农田土壤湿度对土壤呼吸的影响,而臭氧浓度升高可能降低了冬小麦农田土壤硝化速率和反硝化速率,但降低幅度均不显著。

Since the spring of 2010, we used open-top chamber for ozone (OTC) field experiment in Nanjing University of Information Science &Technology agriculture experiment stations;the ozone automatic generation and regulation system was used to simulate the environment of rising ozone concentration, to measure soil respiration rate, nitrification and denitrification rate. Meanwhile, we observed soil temperature and soil moisture, and discussed the effect of rising ozone concentration on soil respiration, nitrification and denitrification in winter wheat field. The results showed that rising ozone concentration had no significant effect on the change rule of soil respiration rate in winter wheat field during growth period, but it would lower the soil respiration in winter wheat field. At the same time, rising ozone concentration would limit the effect of soil temperature in winter wheat field on soil respiration. With ozone concentration increasing, Q10 value would decrease, which lowered the temperature sensitivity of soil respiration in winter wheat field and decreased the effect of soil temperature in winter wheat field on soil respiration as well, but the rising of ozone concentration might lower nitrification rate and denitrification rate of winter wheat field soil, yet not significant reduction extent.