草坪土壤的N_2O产生途径及其对施氮肥的响应  

Effects in Responses of Turfgrass Soil on Nitrous Oxide Emission Processes to N Application

作　　者：白龙[1] 王跃羲 刘英[1] 王晓红[1] 谭冬梅[1] BAI Long WANG Yue-xi LIU Ying WANG Xiao-hong TAN Dong-mei(College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China)

机构地区：[1]沈阳农业大学园艺学院,沈阳110866

出　　处：《园艺学报》2016年第10期1971-1979,共9页Acta Horticulturae Sinica

摘　　要：硝化作用、反硝化作用和硝化细菌反硝化作用是土壤中产生N_2O的主要途径。以常用的冷季型草坪草早熟禾为对象,采用气体抑制剂培养法研究了不同施氮量对草坪土壤N_2O排放及其产生途径的影响。结果表明,对照草坪土壤的N_2O日排放量为7.2~8.2 g·m^(-2)·d^(-1),年施氮量10 g·m^(-2)未改变草坪土壤N_2O排放强度,年施氮量25、35 g·m^(-2)处理则分别比对照增加1.52倍和1.88倍,但二者之间没有显著差异。对照草坪土壤N_2O产生途径主要以异养硝化作用为主,其贡献率达65.7%,反硝化作用贡献率为34%,自养硝化和硝化细菌反硝化过程几乎不发生。年施氮量25 g·m^(-2)时,N_2O排放以硝化细菌反硝化、异养硝化和反硝化途径为主,贡献率分别为35%、35%和29%。年施氮量35 g·m^(-2)时,N_2O排放来自于4个途径,其中反硝化途径占41%,自养硝化途径贡献率增加至20%。Nitrification,denitrification and nitrifier denitrification are the main microbial producing processes of Nitrous oxide（N2O）in soil. The Nitrous Oxide emission processes of soil and its response to N application were studied by different gas（air,oxygen or acetylene）inhibition methods in Poa pratensis L. The results indicated that the N2O emissions of 10 g · m-2 N applying treatments didn’t increase compared with the control treatment（7.2–8.2 g · m-2 · d-1）;but N2O emissions increased significantly with N applying dose increased to 25 and 35 g · m-2,the N2O emissions were 1.52 and 1.88 times higher than that of the control treatment respectively,and there was no difference between them. The contribution rate of heterotrophic nitrification and denitrification of control treatment reached 65.7% and 34% respectively,and the contribution rate of autotrophic nitrification and nitrifier denitrification were nearly zero. Therefore,heterotrophic nitrification was the dominant process in the control treatment. The contribution rate of nitrifier denitrification,heterotrophic nitrification and denitrification under 25 g · m-2 N applying treatment reached 35%,35% and 29%. Under 35 g · m-2 N applying treatment,N2O emissi on could happen with nitrifier denitrification,heterotrophic nitrification,denitrification and autotrophic nitrification,the contribution rate of autotrophic nitrification and denitrification reached 20% and 41%,respectively.

关 键 词：草坪 施氮肥 N2O排放 硝化作用 反硝化作用 硝化细菌反硝化 

分 类 号：S688.4[农业科学—观赏园艺]