Effects of elevated CO_(2) concentration on CH_(4) and N_(2)O emissions from paddy fields:A meta-analysis  

作　　者：Haiyang YU Tianyu WANG Qiong HUANG Kaifu SONG Guangbin ZHANG Jing MA Hua XU 

机构地区：[1]State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science China Earth Sciences》2022年第1期96-106,共11页中国科学（地球科学英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant No.2017YFD0300105);the National Natural Science Foundation of China(Grant No.41877325);the project of Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2018349)。

摘　　要：The inevitable rise of atmospheric CO_(2) concentration plays an important role in regulating the carbon(C)and nitrogen(N)cycling in the rice-cropping system.Elucidating the effects of elevated CO_(2) concentration(ECO_(2))on CH_(4) and N_(2)O emissions from paddy fields is essential for evaluating agricultural production in response to global climate change.In this study,we conducted a global meta-analysis to assess the overall effect of ECO_(2) on CH_(4) and N_(2)O emissions from paddy fields,aiming at providing a guideline for sustainable C and N management in paddy fields under future climate conditions.The results showed that,overall,ECO_(2) significantly increased CH_(4) emissions from rice fields by 23%(P<0.05),but reduced N_(2)O emissions by 22%(P<0.05).With a long duration(>10 yr)of ECO_(2) ,ECO_(2) significantly reduced CH_(4) and N_(2)O emissions from paddy fields by 27%and 53%,respectively(P<0.05).Along with the increasing levels of ECO_(2) ,the stimulating effect of ECO_(2) on CH_(4) emissions showed a trend of"weakening firstly and then strengthening",while its effect on N_(2)O emissions changed from stimulation to inhibition.Agronomy managements(e.g.,N application rates,straw incorporations,water regimes,and rice cultivars)affected the effects of ECO_(2) on CH_(4) and N_(2)O emissions from paddy fields.With no or half amount of straw incorporation,ECO_(2) increased CH_(4) emissions by 27% or 49%(P<0.05)from paddy fields,respectively,while non-significant effects on CH_(4) emissions from paddy fields were observed under full straw incorporation.With the increasing amount of straw incorporation,the reductions in N_(2)O emissions from paddy fields were enhanced by ECO_(2).Compared with a continuous flooding regime,intermittent irrigation weakened the promoted effect on CH_(4) emissions but stimulated the inhibited effect on N_(2)O emissions from paddy fields under ECO_(2).Therefore,under the future condition of ECO_(2),it is recommended to adopt the appropriate agricultural management measures,such as

关 键 词：Elevated CO_(2) Paddy field CH_(4) N_(2)O Agronomy managements META-ANALYSIS 

分 类 号：X71[环境科学与工程—环境工程] X16