短期培养下抑制剂烯丙基硫脲对土壤硝化作用及微生物的影响  

Effect of Allylthiourea on Soil Nitrification and the Underlying Microbial Mechanism in Short-term Laboratory Microcosms

作　　者：沈晓忆 夏围围 次仁拉姆 李乙坤 SHEN Xiaoyi;XIA Weiwei;Cirenlamu;LI Yikun(Jiangsu Key Laboratory of Agricultural Meteorology,College of Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学应用气象学院/江苏省农业气象重点实验室,南京210044

出　　处：《土壤学报》2021年第6期1552-1563,共12页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41501267);土壤与农业可持续发展国家重点实验室开放课题(Y20160025)资助。

摘　　要：硝化抑制剂烯丙基硫脲(ATU)对土壤硝化作用及温室效应的影响及机理尚不清楚。采集典型旱地土壤,进行21 d室内微宇宙培养,探究氮肥与不同剂量ATU(分别为氮素用量的1%、5%、10%、15%和20%)配施对土壤硝化作用及N_(2)O和CO_(2)排放通量的影响,并通过实时荧光定量PCR和高通量测序16S rRNA基因技术监测硝化微生物群落变化,同时与传统硝化抑制剂双氰胺(DCD)进行保氮减排效果的对比。结果表明,与未施加氮肥的对照(CK)相比,单施氮肥(N)显著提高土壤硝化强度并促进N_(2)O排放。DCD能显著抑制硝态氮和N_(2)O的积累,抑制效率分别为68.6%和93.3%。而低浓度ATU对土壤硝化作用无影响,仅在高浓度具有抑制效应,且抑制效率最高仅为14.7%。所有ATU处理N_(2)O排放量均显著降低,降幅为60.3%~68.2%,仍远高于DCD处理。处理间N_(2)O和CO_(2)的综合温室效应强弱顺序为N>ATU+N>DCD+N≈CK,不同ATU施用量处理之间差异不显著。相关分析发现氨氧化细菌(AOB),而不是氨氧化古菌(AOA)和全程氨氧化细菌(Comammox),与土壤硝态氮积累和N_(2)O排放显著正相关,与土壤pH显著负相关。高通量测序结果表明Nitrosovibrio tenuis类型AOB对氮肥诱导的硝化过程起主导作用。此外,ATU和DCD还能显著提高Cupriavidus,并降低Patulibacter、Aeromicrobium、Actinomycetospora、Defluviicoccus和Acidipila等微生物属在群落中的相对丰度。该研究为深化土壤碳氮循环理论,合理使用硝化抑制剂以及减缓温室气体排放提供科学依据。【Objective】Allylthiourea(ATU)is a promising nitrification inhibitor.However,its effects on soil nitrification and greenhouse gas(GHG)mitigation are still unclear.【Method】In this study,a 21-day microcosm incubation was established with the application of nitrogen(N)and different doses of ATU(1%,5%,10%,15%and 20%of N applied)to a yellow-brown upland soil.Also,dicyandiamide(DCD,10%of N applied)was applied to compare the inhibition efficiency on nitrification and GHG emission with ATU.The dynamics of inorganic nitrogen and N_(2)O/CO_(2) emission during the incubation were detected,and changes in the different microbial population were analyzed by real-time PCR and 16S rRNA gene-based high through-put sequencing.【Result】N application greatly stimulated soil nitrification activity and promoted N_(2)O emission.DCD had a strong inhibitory effect on soil nitrification(68.6%)and N_(2)O emission(93.3%).ATU did not influence soil nitrification at low doses(<5%),but inhibited the nitrate accumulation at high doses(>10%)with the highest inhibition efficiency of 14.7%.All treatments with ATU decreased N_(2)O emission by 60.3%~68.2%but was still much higher than when DCD was applied.In general,the global warming potential(GWP)of N_(2)O and CO_(2) were the highest in N treatment and seconded by ATU+N treatment.There were no significant differences in GWP between DCD+N and CK treatment,or among different doses of ATU with N treatments.The quantitative real-time PCR of amoA genes suggested that ammonia-oxidizing bacteria(AOB)rather than ammonia-oxidizing archaea(AOA)and complete ammonia-oxidizing bacteria(Comammox),had a positive relationship with soil nitrate accumulation and N_(2)O emission,but a negative correlation with pH.Microbial community analysis by high through-put sequencing revealed Nitrosovibrio tenuis-like AOB dominated in soil nitrification process which was greatly stimulated by nitrogen.Besides,ATU and DCD significantly increased the relative abundance of cupriavidus but reduced the relative abundance o

关 键 词：烯丙基硫脲(ATU) 双氰胺(DCD) 硝化作用 N_(2)O 土壤微生物 

分 类 号：X171[环境科学与工程—环境科学] S154.3[农业科学—土壤学]