华北平原冬小麦/夏玉米轮作田土壤N2O通量特征及影响因素  

Characteristics of Soil N_2O Flux in a Winter Wheat-Summer Maize Rotation System in North China Plain and Analysis of Influencing Factors

作　　者：孙艳丽[1] 陆佩玲[1] 李俊[2] 于强[2] 孙善彬[1] 王吉顺[2] 欧阳竹[2] 

机构地区：[1]北京林业大学省部共建森林培育与保护教育部重点实验室,北京100083 [2]中国科学院地理科学与资源研究所

出　　处：《中国农业气象》2008年第1期1-5,15,共6页Chinese Journal of Agrometeorology

基　　金：国家自然科学基金重大项目(30590381-04);国家重点基础研究发展规划项目(2002CB412501);中国科学院地理资源所创新三期领域前沿课题(066U0607SZ)

摘　　要：采用静态箱/气相色谱法对华北平原冬小麦/夏玉米轮作田土壤N2O通量进行周年观测，研究轮作田土壤N2O源的大小及其变化规律，分析土壤温度、水分、有效氮含量对土壤N2O通量的影响。结果表明，土壤N2O通量季节变化明显且变化主要是由施肥引起的。麦田土壤N2O通量变化范围为-36-835μg·m^-2·h^-1，玉米田为-1-263μg·m^-2·h^-1，麦季土壤N2O排放强度（80.5μg·m^-2·h^-1）低于玉米季（90.5μg·m^-2·h^-1）。轮作田土壤N2O年总排放量为6.9kg·hm^-2，麦季（4.2kg·hm^-2）高于玉米季（2.7kg·hm^-2）。土壤N2O通量随地温升高呈指数增长（通过0.01显著水平检验），季节Q10值为2.2，单日的Q10值在3.8-4.5；作物主要生长季（4-10月）土壤N2O通量随土壤中NH4^＋-N含量的增加呈线性增长（通过0.05显著水平检验），而与土壤含水量和NO3^--N含量均未表现出明显数量关系。在作物主要生长季，上述各因子对土壤N2O通量的综合影响极显著（通过0.01显著水平检验），其中土壤含水量和NH4^＋-N含量是主导因素。Soil N2O flux was measured for a whole year in winter wheat- summer maize rotation system in the North China Plain to determine its sources and changes in the soil, by using close chamber method. The relationships between soil N2O flux and soil temperature, moisture and available nitrogen content were analyzed after getting rid of the influence of fertilization. The results indicated that the winter wheat and summer maize fields were sources of N2O. Soil N2O fluxes both in wheat and maize fields showed obvious seasonal variations because of the influence of fertilization. Soil N2O flUX in wheat field ranged from -36 to 835μg·m^-2·h^-1, and in the maize field ranged from -1 to 263μg·m^-2·h^-1 The seasonal average soil N2O flux in wheat field with 80.5μg·m^-2·h^-1 was smaller than in maize field with 90.5μg·m^-2·h^-1. The total soil N2O emission in wheat field with 4.2 kg hm^-2 was higher than in maize field with 2.7 kg hm^-2. Annual soil N2O emission was with 6.9 kg hm^-2. Soil N2O flux increased exponentially with the soil temperature （ P 〈 0.01 ）. Its seasonal Q10 was 2.2, and the diurnal Q10 were from 3.8 to 4.5. There was no obvious correlation between the soil N2O flux and the soil moisture. During main growing seasons （from April to October） the soil N2O flux increased with soil NH4^＋ -N contents （P 〈 0.05 ）. There was no obvious correlation between the soil N2O flux and the NO3^--N and content. During main growing seasons, the comprehensive influence of soil temperature, moisture and NO3^-- N and NH4^＋- N contents on the soil N2O flux was significant （P 〈0.01 ）. Soil moisture and soil NH4^＋-N contents were the main factors controlling soil N2O emission.

关 键 词：土壤N2O通量 华北平原 Q10值 冬小麦/夏玉米轮作田 

分 类 号：S512.11[农业科学—作物学] S513