优化施肥下华北冬小麦／夏玉米轮作体系农田反硝化损失与N2O排放特征  

Effect of optimized nitrogen application on denitrification losses and N_2O emissions from soil in winter wheat/summer corn rotation system in North China

作　　者：王秀斌[1] 梁国庆[1] 周卫[1] 孙静文[1] 裴雪霞[1] 夏文建[1] 

机构地区：[1]中国农业科学院农业资源与区划研究所、农业部植物营养与养分循环重点开放实验章,北京100081

出　　处：《植物营养与肥料学报》2009年第1期48-54,共7页Journal of Plant Nutrition and Fertilizers

基　　金：国家重点基础研究发展计划课题(2007CB109307);国家科技支撑计划课题(2006BAD25B01);中央级公益性科研院所基本科研业务费专项资金资助。

摘　　要：在田间条件下,应用乙炔抑制-原状土柱培养法测定优化施肥下华北冬小麦/夏玉米轮作体系土壤反硝化和N_2O的排放特征。研究表明:冬小麦和夏玉米整个生育期反硝化速率和N_2O排放通量均表现出明显的季节性变化,且均与土壤水分和无机氮浓度呈显著正相关。小麦季和玉米季的反硝化损失量及N_2O排放量均表现出随施肥量的降低而降低,夏玉米季的反硝化损失量和N_2O排放量均高于小麦季。小麦季的反硝化损失量和N_2O排放量习惯施肥处理是氮肥减量后移处理的1.62和1.67倍,玉米季分别为2.01和2.00倍。氮肥减量后移可能是通过改变土壤无机氮浓度而降低反硝化损失量和N_2O排放量。A field experiment was conducted characterize denitrification and N2O emission from soil under optimized nitrogen fertilization in winter wheat/summer corn rotation system in North China using acetylene inhibition-intact soil core incubation technique. Results showed that there were significant seasonal variations of denitrification rate and N2O emission flux during winter wheat/summer corn growth periods, and positive correlations existed between inorganic nitrogen concentration （NH4^＋-N, NO3^--N） and denitrification rate. Total denitrifieation losses and N2O emission amounts from soil in winter wheat/summer corn rotation system were observed to be reduced with decreasing of N application rate, and which in winter wheat season were found to be less than those in summer corn season. Total denitrification losses and N2O emission amounts under conventional N fertilization were respectively 1.62 and 1.67 times as high as those under opti- mized N fertilization during winter wheat growth periods, and 2.01 and 2.00 times during summer corn growth periods, which N application rate decreased by 30% and postponing N application as compared with conventional N fertilization with an application rate of N 300 kg/ha. Therefore, postponing N application could reduce denitrification losses and N2O emission through modifying soil inorganic nitrogen concentration.

关 键 词：冬小麦 夏玉米 氮肥优化施用 反硝化 氧化亚氮 

分 类 号：S512.11[农业科学—作物学] S513