• 关键词：稻鸭复合系统  温室气体  排放通量  温室效应(GWPs)

• 基金项目：国家重大科技专项资助项目(No.2004BA520A02)

• 展茗
• 华中农业大学作物栽培与生理生态研究中心, 武汉 430070

• 曹凑贵
• 华中农业大学作物栽培与生理生态研究中心, 武汉 430070

• 汪金平
• 华中农业大学作物栽培与生理生态研究中心, 武汉 430070

• 李成芳
• 华中农业大学作物栽培与生理生态研究中心, 武汉 430070

• 袁伟玲
• 华中农业大学作物栽培与生理生态研究中心, 武汉 430070

• 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^-2·h^-1,常规淹水稻田(对照)为(9.53±0.40)mg·m^-2·h^-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.

• Abstract：Calculating comprehensive Global Warming Potentials (GWPs) of CO₂, CH₄, N2Ohelp to evaluate the contribution of integrated paddy ecosystems in mitigating greenhouse gas emissions. Emissions of CH₄, N2Oand CO₂ were measured from the soil of an integrated rice paddy/duck pond system using alkali absorption in a closed chamber. Results indicated ①Emission 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 N2Owas lower during the flooded stage, then abruptly increased after drainage during rice ripening. The average flux of N2Owas (0.092±0.073)mg·m^-2·h^-1 for RDand (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 RDand (107.53±3.92)mg·m^-2·h^-1 for CK, but the difference between the two systems was not statistically significant. ②Raising 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 N2Oof RDwas 0.2 g·m^-2, 10% more than CK. There was no significant difference of total CO₂ emission between RD (273.66 g·m^-2) and CK (245.73 g·m^-2). ③CH₄ contributed about 60% to comprehensive GWPs based on paddy greenhouse gases. Contrasted with CK, RDcould effectively decrease GWPof CH₄, thus mitigating the comprehensive GWPof the integrated rice-duck system.

• Key words：integrated rice-duck system  greenhouse gases  emission flux  Global Warming Potential(GWP)

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