有机肥和无机肥对菜地土壤N_2O排放及其来源的影响  

Effects of organic and inorganic fertilizers on emission and sources of N_2O in vegetable soils

作　　者：林伟[1] 丁军军[1] 李玉中[1,2] 徐春英[1] 李巧珍[1] 郑欠 庄姗 LIN Wei, DING Jun-jun, LI Yu-zhong1＇2 , XU Chun-ying1, LI Qiao-zhen, ZHENG Qian, ZHUANG Shan1(1 lnstitue of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences-Key Laboratory of Dryland Farming Agriculture, Ministry of Agriculture, Beijing 100081, China; 2Environmental Stable Isotope Laboratory, Chinese Academy of Agricultural Sciences, Beijing 100081, China)

机构地区：[1]中国农业科学院农业环境与可持续发展研究所/农业部旱地节水农业重点实验室,北京100081 [2]中国农业科学院环境稳定同位素实验室,北京100081

出　　处：《应用生态学报》2018年第5期1470-1478,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41473004;41301553;41701308)资助~~

摘　　要：以北京地区白菜地为研究对象进行肥料试验,结合乙炔抑制试验设置有机肥乙炔组、有机肥无乙炔组、无机肥(尿素)乙炔组、无机肥无乙炔组4个处理,利用N_2O稳定同位素自然丰度技术,研究菜地土壤N_2O排放通量和同位素特征值的变化规律,旨在明确在不同肥料作用下N_2O产生和消耗的微生物途径,为减少菜地N_2O排放和科学施肥提供理论依据.结果表明:在白菜生长期内有机肥乙炔组、有机肥无乙炔组、无机肥乙炔组、无机肥无乙炔组的N_2O总排放量分别为(374±37)、(283±34)、(458±36)、(355±41)g·m^(-2),有机肥处理的N_2O通量显著低于无机肥处理,乙炔组的N_2O通量显著高于无乙炔组;两种肥料处理的N_2O还原程度基本相同,而无机肥处理的硝化作用更高;乙炔仅抑制部分硝化作用,在N_2O排放高峰期也仅抑制部分N_2O还原,当排放降低时才能完全抑制N_2O还原.可见,无机肥尿素能够促进硝化作用进而增加N_2O排放,高浓度的N_2O对乙炔抑制N_2O还原起拮抗作用.因此,在北京地区菜地使用有机肥替代部分无机肥可以有效减少硝化作用触发的土壤N_2O排放,同时在使用乙炔抑制方法研究N_2O来源时应考虑合理的N_2O浓度阈值.To clarify the microbial pathway of the N2O production and consumption under different fertilizers and provide theoretical basis for the reduction of N2O emission and rational management of fertilization in vegetable soils,we examined dynamics of N2O flux and isotope signatures under different fertilizer treatments in the vegetable soils of Beijing,by setting up four treatments(organicacetylene,organic-nonacetylene,inorganic-acetylene,inorganic-nonacetylene） and using the stable isotope technique of natural N2O abundance. The results showed that the cumulative N2O emission from organic-acetylene group,organic-nonacetylene group,inorganic-acetylene group and inorganicnonacetylene group was(374±37）,(283±34）,(458±36）,(355±41） g·m^（-2） in cabbage growing season,respectively. N2O fluxes were significantly lower in treatments with organic fertilizer than those with inorganic fertilizer and significantly higher in acetylene group than nonacetylene group. The degree of N2O reduction were similar in both fertilizer treatments,and higher nitrification was found in inorganic fertilizer than organic fertilizer treatments. Acetylene only inhibited partial nitrification and partial N2O reduction at the peak of N2O emission. When the emission was reduced,N2O reduction could be completely suppressed. Therefore,the inorganic fertilizer might trigger nitrification and promote higher N2O emission. The high concentration of N2O could withstand that acetylene to inhibite N2O reduction. Hence,using organic fertilizers instead of some inorganic ones could effectively reduce N2O emission in vegetable soils of Beijing. The N2O concentration threshold should be considered when we identify N2O source by acetylene inhibition method.

关 键 词：有机肥 硝化作用 N2O还原 同位素特征值 乙炔抑制 

分 类 号：S154[农业科学—土壤学] S63[农业科学—农业基础科学]