摘要
为了探讨不同秸秆还田模式下稻麦两熟农田麦季CH_4和N_2O的排放规律,以江苏省南部地区稻麦两熟农田为研究对象,进行了8年不同秸秆还田模式[即仅麦季稻秸秆还田处理(R)、仅稻季麦秸秆还田(W)和稻麦季秸秆均还田(RW)]的田间定位试验,采用静态箱-气相色谱法分析各处理麦季田间CH_4和N_2O的排放特征。结果表明,与秸秆不还田对照(CK)相比,秸秆还田可增加麦季CH_4和N_2O的排放通量。各处理间CH_4的累积排放量大小为R处理>RW处理>W处理>CK对照,麦季N_2O的累积排放量大小为W处理>R处理>RW处理>CK对照。各秸秆还田模式(R、W、RW)下,麦季CH_4和N_2O的全球增温潜势(GWP)分别为1 225.5 kg/hm^2,CO_2-eq、1 250.9kg/hm^2,CO_2-eq和1 214.5 kg/hm^2,CO_2-eq,均显著(P<0.05)高于秸秆不还田的1 068.5 kg/hm^2,CO_2-eq。各处理间的单位产量GWP表现为RW处理>W处理>R处理>CK对照,稻麦秸秆均全量还田对气候变化的影响最大。N_2O对总增温潜势的贡献率大于95%,是麦季减排的主要对象。从对气候变化影响的角度考虑,建议秸秆单季还田时采用稻秸秆全量还田。
In order to investigate methane(CH4) and nitrous oxide(N2O) emission fluxes under different straw returning patterns, an 8-year field trial in Suzhou, typical rice-wheat double cropping region in southern area of Jiangsu province, was conducted using static chamber-gas chromatograph technique in situ.Straw returning patterns were rice straw returning (R), wheat straw returning (W), both rice straw and wheat straw returning (RW) and no straw returning treatment (CK).The results showed that total CH4 and N2O emissions in straw returning treatments were significantly (P<0.05) higher than those in CK treatment, but the changes between the three straw returning patterns were not distinct.Total CH4 emissions under different treatments followed the order of R>RW>W>CK, while W>R>RW>CK for the total N2O emission during the whole wheat-growing season.Global warming potentials (GWPs) for treatments of R, W and RW were 1 225.5 kg/hm2,CO2-eq, 1 250.9 kg/hm2,CO2-eq and 1 214.5 kg/hm2,CO2-eq, respectively, which were significantly (P<0.05) higher than that of CK treatment [1 068.5 kg/hm2,CO2-eq].The yield-scaled GWPs between treatments followed the order of RW>W>R>CK, showing that both rice straw and wheat straw returning pattern had the most significant impact on climate change during wheat-growing season.The contribution rates of N2O to GWPs were more than 95% for all straw returning treatments, indicating that N2O was the main objection for greenhouse gas reductions during wheat-growing season.Given that R treatment had the least GWP, rice straw returning pattern should be recommended for one-season straw returning application.
出处
《江苏农业学报》
CSCD
北大核心
2017年第2期-,共7页
Jiangsu Journal of Agricultural Sciences
基金
江苏省农业科技自主创新基金项目[CX(12)1002]
关键词
秸秆还田模式
麦季
CH4
N2O
排放特征
straw returning pattern
wheat-growing season
CH4
N2O
emission characteristics
