华东稻麦轮作农田CH_4、N_2O和NO排放特征  

CH_4,N_2O and NO Emissions from a Rice-wheat Rotation Cropping Field in East China

作　　者：周再兴[1] 郑循华[1] 王明星[1] Klaus Butterbach-Bahl 

机构地区：[1]中国科学院大气物理研究所 [2]Institute for Meteorology and Climate Research,Karlsruhe Research Center, Krueckbahnstrasse 19,D-82467,Garmisch-Partenkirchen,Germany

出　　处：《气候与环境研究》2007年第6期751-760,共10页Climatic and Environmental Research

基　　金：国家自然科学基金49675270

摘　　要：利用同步自动观测系统对华东稻麦轮作农田的CH4、N2O和NO排放进行了长期连续观测,分析了这3种气体排放的季节特征及决定因素,结果表明,华东稻麦轮作农田的CH4、N2O和NO排放具有完全不同的季节变化形式。CH4的排放发生在水稻生长期,其他阶段排放不明显,土壤水分状况是决定整个轮作周期内CH4排放变化的主要因素。N2O排放具有"冬季无,水田少,旱地多"的季节变化特点,尤其以旱地阶段的排放为主,土壤水分状况和温度共同决定着N2O排放的季节变化形式。NO排放具有"冬季无,水田很少,春季旱地多于秋季旱地"的季节分布特点,轮作周期内97.3%±0.6%的NO排放都发生在除冬季以外的旱地阶段,NO排放的季节变化形式由土壤水分状况和温度共同决定。大多数情况下稻田CH4和N2O排放呈互为消长的关系,但在烤田期间,二者却有时甚至同时出现高排放。在N2O日平均排放通量小于5 mg.m-2.h-1时,稻麦轮作农田的N2O和NO排放呈明显的互为消长关系,但大于5 mg.m-2.h-1时,N2O排放很强,同时NO排放也很强。CH4,N2O and NO emissions from a rice-wheat rotation cropping field were investigated simultaneously with an automatic observation system in East China.Based on one and half year data,the following conclusions were drawn.The three gases had different seasonal emission patterns from the fields.CH4 emission occurred approximately during the rice season relating to the special water regime.Soil water content was the main environmental factor affecting CH4 emission during an entire rotation.N2O emission was high during the upland period,relatively low during rice season,sometimes not being able to detect.The seasonal dynamic of N2O emission had dependency on both soil water content and soil temperature.NO had different emission characteristic that the flux was relatively high from upland soil,low during rice season,seldom detected in winter,and much higher in spring than that in the fall during upland period.97.3%±0.6% of NO emission in a rotation occurred during upland period excluding winter.NO emission was dependent on both soil water content and soil temperature like N2O.Generally,CH4 and N2O emissions from rice field had a tradeoff relation.During the drainage period,however,the two gas species sometimes were not certain to have such a tradeoff relation,but released at high rates of flux simultaneously.When daily N2O emission flux was less than 5 mg·m^-2 ·h^-1,N2O and NO emissions had a obvious tradeoff relation as well.On the contrary,NO emission was also high while N2O emission occurred high with a rate of more than 5 mg·m^-2·h^-1.

关 键 词：CH4 N2O NO 稻麦轮作 同步自动观测 华东 

分 类 号：X142[环境科学与工程—环境科学]