中文关键词氮迁移同位素示踪反硝化厌氧氨氧化(ANAMMOX)脱氮贡献 英文关键词nitrogen migrationisotope tracingdenitrificationanaerobic ammonia oxidation (ANAMMOX)contribution to N loss

作者	单位	E-mail
陈志浩	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, 南京 210023	2935518658@qq.com
覃云斌	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, 南京 210023
丁帮璟	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, 南京 210023
胡优优	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, 南京 210023
陈湜	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, 南京 210023
李正魁	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, 南京 210023	zhkuili@nju.edu.cn

中文摘要 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. 英文摘要 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 wheat-rice 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.

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