稻鸭复合系统的温室气体排放及其温室效应  

Greenhouse gas emissions from an integrated rice-duck system and its Global Warming Potentials (GWPs)

作　　者：展茗[1] 曹凑贵[1] 汪金平[1] 李成芳[1] 袁伟玲[1] 

机构地区：[1]华中农业大学作物栽培与生理生态研究中心,武汉430070

出　　处：《环境科学学报》2009年第2期420-426,共7页Acta Scientiae Circumstantiae

基　　金：国家重大科技专项资助项目(No.2004BA520A02)~~

摘　　要：利用密闭箱技术和碱液吸收法,通过田间试验研究了稻鸭复合系统土壤CH4、N2O和CO2的排放规律及其温室效应.结果表明:①在水稻生长期间,CH4分别在分蘖期和抽穗期出现2个排放高峰,平均排放通量养鸭处理为(7.68±0.74)mg·m-·2h-1,常规淹水稻田(对照)为(9.53±0.40)mg·m-·2h-1;N2O排放通量呈现出在稻田淹水期间保持较低值,在稻田落干后迅速升高的趋势,平均排放通量养鸭处理为(0.092±0.073)mg·m-2·h-1,对照为(0.082±0.074)mg·m-2·h-1;而CO2的排放则在分蘖期和成熟期田面水逐渐落干后呈现2个排放峰,养鸭处理和对照的平均排放通量分别为(121.20±4.21)mg·m-2·h-1和(107.53±3.92)mg·m-2·h-1.②稻田养鸭显著地降低了CH4的排放,水稻整个生育期间排放量为18.41g·m-2,比对照减少19.3%;而显著地提高了N2O的排放,整个生育期间排放量为0.2g·m-2,比对照增加了10%;养鸭稻田土壤CO2的总排放量为273.66g·m-2,对照为245.73g·m-2,两者之间没有显著性的差异.③CH4是引起稻田温室气体综合温室效应的主体,其贡献率在60%左右,相对于常规稻作,稻田养鸭能有效降低甲烷的温室效应,使其温室气体的综合温室效应显著降低,说明在中国南部稻鸭共作是一个减缓全球温室效应的可行措施.Calculating comprehensive Global Warming Potentials （GWPs） of CO2, CH4, N2 O help to evaluate the contribution of integrated paddy ecosystems in mitigating greenhouse gas emissions. Emissions of CH4 , N2O and CO2 were measured from the soil of an integrated rice paddy/duck pond system using alkali absorption in a closed chamber. Results indicated （1）Emission flux of CH4 showed two peaks： at the middle tillering stage and the heading stage of rice development. The average flux of CH4 for the rice-duck system （RD） reached （7.68 ± 0.74） mg· m^- 2· h^-1 , while it was （9.53 ± 0.40） mg· m^- 2· h^-1 for the conventional system （CK）. The emission flux of N2O was lower during the flooded stage, then abruptly increased after drainage during rice ripening. The average flux of N2O was （0. 092 ± 0. 073 ） mg· m^- 2· h^-1 for RD and （0. 082 ± 0. 074 ） mg· m^- 2· h^-1 for CK. The emission flux of CO2 had two peaks-at the tillering stage and the ripening stage of the rice-with average flux of （ 121.20 ± 4.21 ）mg· m^- 2· h^-1 for RD and （107.53 ± 3.92）mg· m^- 2· h^-1 for CK, but the difference between the two systems was not statistically significant. （2）Raising ducks in the paddy field could reduce CH4 emission significantly. The total emission of CH4 was 18.41 g·m^-2 during rice growth stage, 19.3% lower than CK. But the total emission of N2O of RD was 0.2 g·m^-2, 10% more than CK. There was no signifieant difference of total CO2 emission between RD （273,66 g·m^-2） and CK （245.73 g·m^-2）. （3）CH4 contributed about 60% to comprehensive GWPs based on paddy greenhouse gases. Contrasted with CK, RD could effectively decrease GWP of CH4 , thus mitigating the comprehensive GWP of the integrated rice-duck system.

关 键 词：稻鸭复合系统 温室气体 排放通量 温室效应(GWPs) 

分 类 号：X511[环境科学与工程—环境工程]