保护性耕作条件下小麦田N_2O排放及影响因素研究  

Study of N_2O Emission and Its Affecting Factors in Wheat Fields of Conservation Tillage

作　　者：赵建波[1] 迟淑筠[1] 宁堂原[1] 李增嘉[1] 谷淑波[1] 裘立群[1] 吕美容[1] 田慎重[1] 

机构地区：[1]山东农业大学农学院国家作物生物学重点实验室,山东泰安271018

出　　处：《水土保持学报》2008年第3期196-200,共5页Journal of Soil and Water Conservation

基　　金：国家粮食丰产工程项目(2004BA520A14C10);国家科技支撑计划项目(2006BAD10B07)

摘　　要：采用静态箱—气相色谱法对保护性耕作和常规耕作小麦田的N_2O排放进行了原位测量,测量了土壤温度、水分、无机氮等相关影响因子。结果表明:(1)保护性耕作及常规耕作麦田N_2O的排放具有明显的季节性变化规律,各处理变化趋势较为一致。(2)N_2O的平均排放通量和季节排放量,除免耕秸秆还田外,保护性耕作与常规耕作差异显著。(3)在小麦生长季内,保护性耕作农田均表现为N_2O的排放源。(4)各处理N_2O季节排放量大小顺序为:耙耕秸秆还田(1.64 kg/hm^2)>旋耕秸秆还田(1.59 kg/hm^2)>常规耕作秸秆还田(1.48 kg/hm^2)>深松秸秆还田(1.42 kg/hm^2)>常规耕作无秸秆还田(1.34 kg/hm^2)>免耕秸秆还田(1.33 kg/hm^2),即,与常规耕作相比,保护性耕作(除免还)N_2O排放量增加。(5)温度是制约N_2O排放的关键因素,随着温度的升高N_2O表现出增加的趋势。(6)N_2O排放与水分、土壤无机氮含量无相关性。The N2O emission fluxes and seasonal variations of conservation tillage and conventional tillage in wheat fields were sampled with static closed chamber and measured by gas chromatograph. In order to find the relationship between the N2O emission and the impact factors,the temperature, water content and mineralized N of soil were observed at the same time. The results showed that： （1）There were significant seasonal variations of N2O emissions in wheat fields of conservation tillage and conventional tillage with the same trends of change in different treatments. （2）The N2O fluxes and seasonal N2O emission were notable difference between conservation tillage and conventional tillage except no tillage with straw covered（NS）. （3）In the wheat growth stage, the fields of conservation tillage were the resources of N2O emission. （4）The sequence of N2O emission in different treatments was harrow tillage with straw returning（HS）〉 rotary tillage with straw returning（RS）〉 conventional tillage with straw returning（CS）〉 subsoiling tillage with straw returning（PS）〉 no tillage with straw covered（NS）〉 conventional tillage with no straw returning（CN）. Comparing with conventional tillage,N2O fluxes of conservation tillage （except NS） were increased. （5）The temperature was the primary factor that influenced N2O emission, N2O emission was enhanced with the increase of temperature. （6） Water content and mineralized N of soil were not related to N2O emission.

关 键 词：保护性耕作 秸秆还田 N2O排放 影响因素 

分 类 号：S181[农业科学—农业基础科学] S151.93