宛山荡农田土壤氮迁移过程反硝化与厌氧氨氧化  

Denitrification and Anaerobic Ammonium Oxidation in Soil Nitrogen Migration Process in a Farmland of Wanshandang Lake

作　　者：陈志浩 覃云斌 丁帮璟 胡优优 陈湜 李正魁[1] CHEN Zhi-hao;QIN Yun-bin;DING Bang-jing;HU You-you;CHEN Shi;LI Zheng-kui(State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing 210023,China)

机构地区：[1]南京大学环境学院污染控制与资源化研究国家重点实验室

出　　处：《环境科学》2020年第1期412-419,共8页Environmental Science

基　　金：国家水体污染控制与治理科技重大专项(2017ZX07204-004,2018ZX07208-001)

摘　　要：为探究中国南方农田土壤氮迁移过程的反硝化与厌氧氨氧化(anaerobic ammonia oxidation,ANAMMOX)速率变化和脱氮贡献本研究采集宛山荡麦稻轮作区农田不同层深土壤及农田、沟道、河岸带和湖泊沉积物等不同土地利用类型土壤样品,分析其理化性质采用Illumina MiSeq测序和实时荧光定量PCR (quantitative real-time PCR,qPCR)技术探究土壤样品的微生物群落组成和功能基因丰度应用同位素培养实验测定各样品的潜在反硝化与厌氧氨氧化速率(以N2计,下同).结果表明,土壤反硝化速率与TOC、NH4+-N和NO3--N含量均显著正相关(P<0.05),与nirS、nirK及nosZ等功能基因丰度亦呈显著正相关(P <0.05).农田表层土壤反硝化速率为(11.51±1.04) nmol·(g·h)-1,显著高于农田其他土壤层以及其他土地利用类型(P <0.05),而农田土壤中厌氧氨氧化速率在20~30 cm层最高,达到(0.48±0.07) nmol·(g·h)-1.此外,反硝化作用是农田表层土壤氮损失的主要原因,占91.9%~99.7%,而厌氧氨氧化在深层土壤N2的产生过程中占有重要地位.To explore the rate variation and contribution to N loss of denitrification and anaerobic ammonia oxidation(ANAMMOX) in the nitrogen migration process of farmland soils in southern China,we assess the physicochemical characteristics soil samples of different soil layers from farmland and different land use types(farmland,river channel,riparian zone,and lake sediment) in a wheatrice rotation area of Wanshandang Lake.Illumina MiSeq sequencing and quantitative real-time polymerase chain reaction(qPCR) are used to investigate the microbial community composition and functional gene abundances of the samples.The potential denitrification and ANAMMOX rate(calculated by N2) of each sample was determined by an isotope culture experiment.It was demonstrated that the potential denitrification rate was significantly positively correlated with TOC,NH4+-N,and NO3-N(P <0.05),and with the abundances of nirS,nirK,and nosZ(P <0.05).The denitrification rate of surface soils was(11.51±1.04) nmol·(g·h)-1,which was significantly higher than other soil layers and other land use types(P <0.05).While the ANAMMOX rate in farmland soils was the highest in the 20-30 cm layer and reached(0.48±0.07) nmol·(g·h)-1.In addition,denitrification was the main cause of N loss in surface soils of the studied farmland,accounting for 91.9%-99.7% of overall loss,and ANAMMOX played an important role in the production of N2 in deep soils.

关 键 词：氮迁移 同位素示踪 反硝化 厌氧氨氧化(ANAMMOX) 脱氮贡献 

分 类 号：X172[环境科学与工程—环境科学]