不同耕作措施下小麦–玉米轮作农田温室气体交换及其综合增温潜势  

Greenhouse gas exchange and comprehensive global warming potential under different wheat-maize rotation patterns

作　　者：闫翠萍[1] 张玉铭[2] 胡春胜[2] 董文旭[2] 王玉英[2] 李晓欣[2] 秦树平[3] 

机构地区：[1]山西省农业科学院小麦研究所,临汾041000 [2]中国科学院遗传与发育生物学研究所农业资源研究中心/中国科学院农业水资源重点实验室/河北省节水农业重点实验室,石家庄050022 [3]福建农林大学资源与环境学院,福州350002

出　　处：《中国生态农业学报》2016年第6期704-715,共12页Chinese Journal of Eco-Agriculture

基　　金：国家自然科学基金面上项目(41571291);国家自然科学基金重点项目(41530859);中国科学院科技服务网络计划(KFJ-EW-STS-055-2;KFJ-SW-STS-142);国家科技支撑计划项目(2013BAD05B00)资助~~

摘　　要：研究不同耕作措施下小麦-玉米轮作农田N_2O、CO_2和CH4等温室气体的综合增温潜势,有助于科学评价农业管理措施在减少温室气体排放和减缓全球变暖方面的作用,为制定温室气体减排措施提供依据。基于2001年开始的位于华北太行山前平原中国科学院栾城农业生态系统试验站的不同耕作与秸秆还田方式定位试验,应用静态箱/气相色谱法于2008年10月冬小麦播种时开始,连续两个作物轮作年动态监测了秸秆整秸覆盖免耕播种(M1)、秸秆粉碎覆盖免耕(M2)、秸秆粉碎还田旋耕(X)、秸秆粉碎还田深翻耕(F)和无秸秆还田深翻耕(CK,代表传统耕作方式)5种情况下冬小麦-夏玉米轮作农田土壤N_2O、CO_2和CH4排放通量,并估算其排放总量。试验期间同步记录每项农事活动机械燃油量、灌溉耗电量、施肥量,依据燃油、耗电和单位肥料量的碳排放系数统一转换为等碳当量,测定作物产量、地上部生物量,估算农田碳截存量,根据每个分支项对温室效应的作用估算了5个处理的综合增温潜势。结果表明,华北小麦-玉米轮作农田土壤是N2O和CO2的排放源,是CH4的吸收汇,每年M1、M2、X、F和CK农田土壤N2O排放总量依次为2.06 kg(N_2O-N)·hm^(-2)、2.28 kg(N_2O-N)·hm^(-2)、2.54 kg(N_2O-N)·hm^(-2)、3.87 kg(N2O-N)·hm^(-2)和2.29 kg(N2O-N)·hm^(-2),CO_2排放总量依次为6904 kg(CO_2-C)·hm^(-2)、7 351 kg(CO2-C)·hm^(-2)、8 873 kg(CO_2-C)·hm^(-2)、9 065 kg(CO2-C)·hm^(-2)和7 425 kg(CO2-C)·hm^(-2),CH4吸收量依次为2.50 kg(CH4-C)·hm^(-2)、1.77 kg(CH4-C)·hm^(-2)、1.33 kg(CH4-C)·hm^(-2)、1.38 kg(CH4-C)·hm^(-2)和1.57kg(CH4-C)·hm^(-2)。M1和M2处理农田生态系统综合增温潜势(GWP)均为负值,表明免耕情况下农田生态系统为大气的碳汇,去除农事活动引起的直接或间接排放的等当量碳,每年农田生态系统净截留碳947~1 070 kg(C)·hm^(-2);其他处理农田生态系统的GWP值均为正值,表明温室�Studies on the emissions of greenhouse gases and global warming potential（GWP） under different tillage systems have benefited scientific research on the effects of agricultural management on mitigating greenhouse gas emission and reducing global warming. Such studies have also laid the theoretical basis for establishing measures to reduce global greenhouse gas emissions. Long term tillage and straw return to soil experiments were set up in 2001 at the Luancheng Agro-ecosystem Experimental Station（LAES） of Chinese Academy of Sciences. The experiments included 5 treatments — no-tillage with whole maize residue mulching（M1）, no-tillage with chopped maize residue mulching（M2）, rotary tillage with chopped maize residue incorporation（X）, mouldboard ploughing with chopped maize residue incorporation（F） and mouldboard ploughing with maize residue remove（CK, representing conventional tillage method）. The experiment monitored N2 O, CO2 and CH4 fluxes in wheat-maize rotation fields using the static chamber method / gas chromatography technique for the period from October 2008 to September 2010. Total greenhouse gas emissions and GWP were also estimated. Meanwhile, during the experimental period, the amount of fuel consumed by farm machines and power consumed during irrigation and fertilizer application were recorded and transformed to carbon equivalent using a transformation coefficient. In the study, crop yield and aboveground biomasses were measured and carbon sequestration calculated. The total GWP under the 5 tillage treatments were estimated based on the identified parameters of greenhouse effect. The results indicated that wheat-maize rotation fields served as the source of N2 O and CO2, and also the sink of CH4. In M1, M2, X, F and CK treatments, total N2 O emissions from soil were 2.06 kg（N2O-N）·hm-2·a-1, 2.28 kg（N2O-N）·hm-2·a-1, 2.54 kg（N2O-N）·hm-2·a-1, 3.87 kg（N2O-N）·hm-2·a-1 and 2.29 kg（N2O-N）·hm-2·a-1; total CO2 emissions from soil of 6 904 kg（CO2-C�

关 键 词：耕作措施 秸秆还田 温室气体 温室效应 增温潜势 小麦–玉米轮作系统 

分 类 号：S341[农业科学—作物栽培与耕作技术]