硝化抑制剂对蔬菜土硝化和反硝化细菌的影响  

Mechanism of nitrification inhibitor on nitrogen-transformation bacteria in vegetable soil

作　　者：杨扬[1,2,3,4] 孟德龙[1,3] 秦红灵[1,3] 吴敏娜[1,3,5] 朱亦君[1,3] 魏文学[1,3] 

机构地区：[1]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,长沙410125 [2]天津市国土资源和房屋管理研究中心,天津300041 [3]中国科学院桃源农业生态试验站,湖南415700 [4]中国科学院研究生院,北京100049 [5]新乡医学院,新乡450003

出　　处：《生态学报》2012年第21期6803-6810,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(40771115);中国科学院创新团队项目(KZCX2-YW-T07);中国科学院知识创新工程重要方向项目(KSCX2-EW-G-16)

摘　　要：土壤N素循环主要是微生物驱动的转化过程,然而对其的驱动与调控机理了解还很不够。选取长沙黄兴镇蔬菜基地两种蔬菜土研究硝化抑制剂(DCD)对N素转化过程及功能微生物的影响。试验通过室内土壤培养,处理为单施尿素(CK)和尿素与硝化抑制剂双氰胺配合施用(DCD),重复3次。在培养过程中系统监测了土壤中NH+4-N、NO-3-N含量变化,同时采用荧光定量PCR(real-time PCR)方法研究硝化抑制剂对土壤中氮素转化功能基因丰度的影响。结果表明:在培养过程中DCD处理使两个供试土壤的NH+4浓度稳定在较高水平,而NO-3浓度则明显低于对照;施用DCD导致土壤中硝化基因amoA丰度显著减少,而对16S rRNA和反硝化基因nirK丰度没有产生明显影响。因此,DCD在菜地土壤中主要通过抑制氨氧化细菌的繁衍来抑制硝化作用。Nitrogen （N） loss via nitrate （NO3-） leaching from soil is one of the major contributors to environmental degradation. Vegetable soil is characterized by intensive fertilization with low nitrogen usage efficiency as a result of NO3- leaching. Nitrification and denitrification are the most important processes in NO3- formation and transformation, and are driven by functional microorganism in soil. The use of nitrification inhibitors, such as DCD, may play a key role in mitigating N loss. Investigations were conducted on the inhibitory effect of DCD to the functional microorganisms among the processes of nitrification and de-nitrification, and the relationship between DCD and nitrogen transformation. In this research, two kinds of vegetable soils were selected from Huangxing country, Changsha, reflecting long-term （ about 20 years） and short-term vegetable cropping （1 year）. Each sample was a mixture of 5 cores（0--20cm top soil） randomly taken in the same field Two treatments for each soil sample were conducted ： CK treatment （ urea at 0.2g N/kg）, and DCD treatment （ urea at 0. 2g N/kg with DCD 0. 02g/g）, each treatment with 3 replicates. The pots were incubated for 64 days at 25℃, and systematically measured NH4＋ and NO3- concentrations. According to the dynamics of NH4 transformation, three soil samples were taken at the 3rd, 7th and 64th days, which represented the increasing, peak and decreasing status of NH4＋ concentration. The abundances of nitrifying gene amoA and denitrifying gene nirK were analyzed by Real-time PCR,. Results indicated that NH4 concentrations of DCD treatments increased 248% and 225% compared to the CK treatment in the long-term and short term vegetable soils, respectively. NO3- concentrations of DCD treatments decreased 31% and 20% compared to the CK treatment in the long-term and short-term vegetable soils separately. Furthermore, NH4 concentration of DCD treated short term soil decreased slightly while long term soil remained the same level, suggesti

关 键 词：硝化 DCD 蔬菜土 AMOA基因 

分 类 号：S63[农业科学—蔬菜学]