氮肥品种和含水量对水稻土N_2O排放速率及排放过程的影响  

Effects of nitrogen fertilization and water content on the process and rate of N_2O emission in paddy soils

作　　者：席瑞泽 付庆灵[1] 杨永强 尤锦伟 朱俊[1] 胡红青[1] 叶磊 XI Rui-ze;FU Qing-ling;YANG Yong-qiang;YOU Jin-wei;ZHU Jun;HU Hong-qing;YE Lei(College of Resource and Environment, Huazhong Agricultural University, Wuhan 430070, China;Tuanlin Irrigation Experimental Sta- tion, Zhanghe Water Engineering Authority, Jingmen 448800, China)

机构地区：[1]华中农业大学资源与环境学院,武汉430070 [2]荆门市漳河管理局团林灌溉试验站,湖北荆门448800

出　　处：《农业环境科学学报》2017年第12期2553-2560,共8页Journal of Agro-Environment Science

基　　金：湖北省自然科学基金项目(2015CFB481)~~

摘　　要：稻田是全球重要的N_2O排放源,氮肥有效性和水分状况是影响稻田N_2O排放的关键因素。为探明水稻土在施用尿素和硫酸铵时,水分变化对短时间内N_2O总排放速率及不同硝化过程(自养硝化、异养硝化、非生物作用)贡献的影响,通过室内培养实验,采用乙炔抑制法,测定了不同时间段N_2O释放量,并计算释放速率。结果表明:施用氮肥可以显著提高自养硝化、异养硝化及总过程的N_2O排放速率,并且施尿素处理N_2O排放速率大于施硫酸铵。随着土壤水分含量由48%增加至160%,总N_2O排放速率以及自养硝化、异养硝化N_2O排放速率显著增加。供试水稻土N_2O的产生主要是由生物过程主导的,其中硝化作用(包括自养硝化、异养硝化)最高贡献达51.1%,非生物作用贡献所占比重很小。这些结果可为科学施肥,降低农田土壤N_2O排放提供科学依据。Paddy soil is an important source of N2O emission, and nitrogen availability and soil moisture are the key factors affecting the e- mission of N2O. The influence of nitrogen form（ urea and ammonium sulfate ） and water content on the attribution of autotrophic, heterotroph- ie, and abiotic nitrification to N2O emission from the paddy soil was investigated under simulated conditions by using the acetylene inhibition method to measure the N2O emission rate at different stages. The results showed that the nitrogen fertilizer significantly increased the rate of N2O emission by autotrophic and heterotrophic nitrification processes and the total process. The N2O emission of the soil treated with urea was higher than that of the soil treated with ammonium sulfate. With the soil moisture content ranging from 48% to 160%, the total N2O e- missions and the amount of N2O emitted by autotrophic and heterotrophic nitrification processes increased significantly. The production of N2O is mainly dominated by the biological processes. The highest contribution of the biological nitrification process（ including autotrophic and heterotrophic nitrification ） reached 51.1%, but the contribution of abiotic nitrification was relatively less. These results provide a scien- tific base for improving the nitrogen-use efficiency of rice plants and for reducing the agricultural greenhouse-gas emission in paddy soils.

关 键 词：N2O 水稻土 自养硝化 异养硝化 非生物作用 

分 类 号：X511[环境科学与工程—环境工程]