不同灌溉方式对华北平原冬小麦田土壤CO2和N2O排放通量的影响  

Effect of Irrigation Patterns on Soil CO_2 and N_2O Emissions from Winter Wheat Field in North China Plain

作　　者：郭树芳[1] 齐玉春[1] 尹飞虎[2] 彭琴[1] 董云社[1] 贺云龙[1] 闫钟清 

机构地区：[1]中国科学院地理科学与资源研究所,中国科学院陆地表层格局与模拟重点实验室,北京100101 [2]新疆农垦科学院,石河子832000

出　　处：《环境科学》2016年第5期1880-1890,共11页Environmental Science

基　　金：公益性行业(农业)科研专项(201203012-6);国家自然科学基金项目(41373084,41330528,41203054,41573131)

摘　　要：节水灌溉是现代农业的发展趋势,为研究节水灌溉措施对农田土壤温室气体排放的影响,采用静态箱暗箱法研究了微喷水肥一体化(微喷)与传统漫灌方式下华北平原西部2013~2014年冬小麦田土壤CO_2及N_2O排放通量的变化特征及微喷方式下垂直微喷管不同距离的3个空间位置土壤CO_2、N_2O排放通量的空间变化.利用根排除法分析土壤呼吸组分,并估算不同灌溉方式下农田碳收支状况.结果表明:1微喷与漫灌方式下小麦田土壤CO_2排放通量平均值分别为418.19mg·(m^2·h)^(-1)和372.14 mg·(m^2·h)^(-1),两种灌溉方式间CO_2排放通量无显著差异,累积排放量分别为2 150.6 g·m^(-2)及1 904.6 g·m^(-2).2返青期-成熟期微喷方式下距离微喷管不同距离的3个位置土壤CO_2累积排放量表现为距离微喷管近的土壤CO_2排放量最大,但无明显差异.3微喷和漫灌方式下,小麦生长季土壤异养呼吸排放量(以C计)分别为468.49 g·m^(-2)和427.31 g·m^(-2),净初级生产力(以C计)分别为1 988.21 g·m^(-2)和1 770.54 g·m^(-2),生长生育期小麦田碳汇(以C计)分别为1 519.72 g·m^(-2)和1 343.24 g·m^(-2).4微喷与漫灌处理小麦生长季土壤N_2O排放通量的平均值分别为50.77μg·(m^2·h)^(-1)和28.81μg·(m^2·h)^(-1),两种灌溉方式间N_2O排放通量无显著差异,累积排放量分别为272.67 mg·m^(-2)及154.08 mg·m^(-2).5小麦返青期-成熟期微喷方式下3个空间位置土壤N_2O排放通量表现为距离微喷管越远,N_2O累积排放量越小,但处理间无显著性差异.可见,小麦田由传统漫灌转变为微喷节水灌溉后,农田土壤CO_2和N_2O排放通量均有增加,但农田碳汇强度也增加了.The water-saving irrigation is the trend of modernized agriculture. This paper aimed to study the effect of water-saving irrigation on soil CO2 and N2O emissions. The field experiments were conducted under micro sprinkler irrigation of integrated water and fertilizer（ MSI） and conventional flooding irrigation（ FI） in winter wheat growth season in the west of North China Plain during 2013-2014 using the static chamber method. This paper analyzed the seasonal variation of soil CO2 and N2O emissions under MSI and FI,and then compared the soil CO2 and N2O emissions from treatments located in different vertical distance away from micro sprinkler pipe. Root exclusion was used to estimate the components of soil respiration and agricultural carbon sequestration intensity under MSI and FI in winter wheat field. The results indicated that： 1 The average soil CO2 emissions under MSI and FI were 418. 19mg·（ m^2·h）^-1and 372. 14 mg·（ m^2·h）^-1respectively with no significant difference,and cumulative CO2 emissions under MSI and FI were 2 150. 6 g·m^-2and 1 904. 6 g·m^-2,respectively. 2 During returning green stage to harvest stage of winter wheat,the highest soil CO2 cumulative emissions were found at the closest site to the micro sprinkler irrigated pipes under MSI. However,there were no significant differences among spatial treatments. 3 Under MSI and FI,soil heterotrophic respiration（ C） was 468. 49 g·m^-2and427. 31 g·m^-2,and the net primary productivity（ C） was 1 988. 21 g·m^-2and 1 770. 54 g·m^-2; the carbon sink（ C） during winter wheat growing season was 1 519. 72 g·m^-2and 1 343. 24 g·m^-2,respectively. 4 The average N2 O emissions under MSI and FI were50. 77 μg·（ m^2·h）^-1and 28. 81 μg·（ m^2·h）^-1respectively with no significant difference. Cumulative N2 O emission under MSI and FI was 272. 67 mg·m^-2and 154. 08 mg·m^-2,respectively. 5 During returning green stage to harvest stage of winter wheat,the farther the distance away from the micro sprinkler irrigated

关 键 词：微喷水肥一体化 碳汇 温室气体 季节变化 空间分布 累积排放量 

分 类 号：X144[环境科学与工程—环境科学]