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Denitrification Rate and Controlling Factors for Accumulated Nitrate in the Deep Subsoil of Intensive Farmlands: A Case Study in the North China Plain

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Pedosphere 2019年第4期29卷 516-526页

作者： YUAN Haijing QIN Shuping DONG Wenxu HU Chunsheng Kiril MANEVSKI LI Xiaoxin Key Laboratory of Agricultural Water Resources Center for Agricultural Resources Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Shijiazhuang 050021 (China) University of Chinese Academy of Sciences Beijing 100049 (China) Department of Agroecology Aarhus University Tjele 8830 (Denmark)

Denitrification in subsoil(to a depth of 12 m) is an important mechanism to reduce nitrate(NO3^-) leaching into groundwater.However, regulating mechanisms of subsoil denitrification, especially those in the deep subsoil beneath the crop root zone, have not been well documented. In this study, soil columns of 0–12 m depth were collected from intensively farmed fields in the North China Plain. The fields had received long-term nitrogen(N) fertilizer inputs at 0(N0), 200(N200) and 600(N600) kg N ha^-1 year^-1. Main soil properties related to denitrification, i.e., soil water content, NO3^-, dissolved organic carbon(DOC), soil organic carbon(SOC),pH, denitrifying enzyme activity(DEA), and anaerobic denitrification rate(ADR), were determined. Statistical comparisons among the treatments were performed. The results showed that NO3^- was more heavily accumulated in the entire soil profile of the N600 treatment, compared to the N0 and N200 treatments. The SOC, DOC, and ADR decreased with increasing soil depth in all treatments,whereas considerable DEA was observed throughout the subsoil. The long-term fertilizer rates affected ADR only in the upper 4 m soil layers. The ADRs in the N200 and N600 treatments were significantly correlated with DOC. Multiple regression analysis indicated that DOC rather than DEA was the key factor regulating denitrification beneath the root zone. Additional research is required to determine if carbon addition into subsoil can be a promising approach to enhance NO3^- denitrification in the subsoil and consequently to mitigate groundwater NO3^- contamination in the intensive farmlands.

关键词： denitrifying enzyme activity dissolved organic carbon nitrate leaching soil organic carbon subsoil denitrification

Is Nitrous Oxide Reduction Primarily Regulated by the Fungi-to-Bacteria Abundance Ratio in Fertilized Soils?

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Pedosphere 2019年第5期29卷 569-576页

作者： MA Shutan WANG Jinyang YAN Xiaoyuan State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008 (China) University of Chinese Academy of Sciences Beijing 100049 (China) School of Environmental Science and Engineering Anhui Normal UniversityWuhu 241002 (China)

The production of nitrous oxide (N2O) is a widespread trait in fungi and is of interest because denitrifying fungi lack the N2O reductase gene (nosZ) that regulates N2O reduction to nitrogen gas (N2). The adaptive ability of soil fungi is better than that of bacteria in acidic soils. We investigated the N2O reduction potential, described by the N2O product ratio (Nn2O), N2O/(N2O+N2), in soils of different types of fields under crop cultivation with different fertilizer inputs and a bare fallow field with no fertilization as a control. The fungi-to-bacteria abundance ratio (Rf/b) was negatively correlated (P denitrifying bacteria. These results provide evidence that compared to the indirect effects of Rf/b、the direct effects of the soil chemical properties have a greater effect on N2O reduction in fertilized soils.

关键词： denitrification potential denitrifying bacteria denitrifying fungi fertilizer input manure application microbial abundance soil acidification soil pH soil residual nitrate

Chronic effects of different fertilization regimes on nirS-type denitrifier communities across the black soil region of Northeast China

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Pedosphere 2020年第1期30卷 73-86页

作者： Xiaojing HU Junjie LIU Dan WEI Ping ZHU Xi'an CUI Baoku ZHOU Xueli CHEN Jian JIN Xiaobing LIU Guanghua WANG Key Laboratory of Mollisols Agroecology Northeast Institute of Geography and AgroecologyChinese Academy of SciencesHarbin 150081(China) Institute of Soil and Fertilizer and Environment Resources Heilongjiang Academy of Agricultural SciencesHarbin 150086(China) Institute of Agricultural Resource and Environment Jilin Academy of Agricultural SciencesChangchun 130033(China) Heihe Branch of Heilongjiang Academy of Agricultural Sciences Heihe 164300(China) Institute of Plant Nutrition and Resources Beijing Academy of Agricultureand Forestry SciencesBeijing 100097(China)

Denitrification is one of the major processes causing nitrogen loss from arable soils.This study aimed to investigate the responses of nir S-type denitrifier communities to different chronic fertilization regimes across the black soil region of Northeast China.Soil samples were collected from sites located in the north(NB),middle(MB),and south(SB)of the black soil region of Northeast China,each with four chronic fertilization regimes:no fertilizer(No F),chemical fertilizer(CF),manure(M),and chemical fertilizer plus manure(CFM).Methods of quantitative polymerase chain reaction(q PCR)and Illumina Mi Seq sequencing were applied to assess the abundance and composition of denitrifier communities by targeting the nir S gene.The results showed that the M and CFM regimes significantly increased the abundances of nir S-type denitrifiers compared with No F at the three locations.The majority of nir S sequences were grouped as unclassified denitrifiers,and the different fertilizers induced little variation in the relative abundance of known nir S-type denitrifier taxa.Over 90%of the sequences were shared among the four fertilization regimes at each location,but none of the abundant operational taxonomic units(OTUs)were shared among the three locations.Principal coordinate analysis(PCo A)revealed that the communities of nir S-type denitrifier were separated into three groups that corresponded with their locations.Although similar fertilization regimes did not induce consistent changes in the nir S-type denitrifier communities,soil p H and NO-3-N content simultaneously and significantly influenced the structure of nir S-type denitrifier communities at the three locations.Our results highlight that geographical separation rather than chronic fertilization was the dominant factor determining the nir S-type denitrifier community structures,and similar chronic fertilization regimes did not induce consistent shifts of nir S-type denitrifier communities in the black soils.

关键词： denitrification denitrifier diversity denitrifying gene geographical separation Illumina MiSeq sequencing manure Mollisols nirS gene quantitative polymerase chain reaction

污水处理反硝化除磷-诱导结晶磷回收工艺中除磷微生物特性

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农业工程学报 2014年第5期30卷 155-161页

作者：邹海明吕锡武李婷东南大学能源与环境学院南京210096 安徽科技学院资源环境系凤阳233100

为探究反硝化除磷-诱导结晶磷回收工艺中缺氧池污泥释磷、吸磷以及微生物特征,利用荧光原位杂交(fluorescence in situ hybridization,FISH)技术、电子扫描显微镜(scanning electron microscope,SEM)观察了微生物的数量、分布和形态;通... 详细信息

为探究反硝化除磷-诱导结晶磷回收工艺中缺氧池污泥释磷、吸磷以及微生物特征,利用荧光原位杂交(fluorescence in situ hybridization,FISH)技术、电子扫描显微镜(scanning electron microscope,SEM)观察了微生物的数量、分布和形态;通过批次试验考察了污泥在厌氧/好氧和厌氧/缺氧2种模式下的释磷和吸磷特征。结果表明:该双污泥系统缺氧池中聚磷菌占总细菌比例的69.7%,明显高于单污泥系统中富集的聚磷菌比例,污泥中的微生物多呈杆状;厌氧/好氧、厌氧/缺氧模式下单位污泥浓度(mixed liquor suspended solids,MLSS)总吸磷量(以PO43--P计)分别为22.84、18.60 mg/g,反硝化聚磷菌(denitrifying polyphosphate-accumulating organisms,DPAO)占聚磷菌(polyphosphate-accumulating organisms,PAO)的比例为81.44%,表明在长期的厌氧/缺氧运行条件下可以富集到以硝酸盐为电子受体的反硝化聚磷菌,同时还存在着仅以氧气为电子受体的聚磷菌;通过pH值和氧化还原电位(oxidation reduction potential,ORP)的实时监测可以快速地了解污水生物处理系统中各类反应的进程,对调控工艺参数有着重要的意义。综上所述,为保证污水生物处理工艺的正常稳定运行,将微生物分析与常规的化学参数分析结合起来考察将是未来发展的必然趋势。

关键词：细菌污泥硝化扫描电子显微技术荧光原位杂交聚磷菌反硝化聚磷菌 fluorescence in situ hybridization (FISH) polyphosphate-accumulating organisms (PAO) denitrifying polyphosphate-accumulating organisms (DPAO)

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缢蛏滩涂养殖环境的细菌群落组成及分析

应用生态学报 2005年第7期16卷 1380-1382页

作者：金珊薛超波王国良陆彤霞王一农陈寅儿宁波大学生命科学与生物工程学院宁波315211

In this study,the bacteria from the mud in tidal-flat Sinonovacula constricta aquaculture area were isolated each month from March to December,2002,and the temporal and spatial distribution of heterotrophic bacteria,ammonifying bacteria,denitrifying bacteria,and sulphate reducing bacteria were analyzed.The results showed that all the 515 isolated bacteria mainly belonged to 1 family and 13 genera.The bacterial flora in different layers of the mud was almost consistent,while the composition was different.The predominant genera were Clostridium,Bacillus,Corynebacterium,Photobacterium,and some Enterobacteriaceae.The number of heterotrophic bacteria in the surface layer and the bottom fluctuated in 7.6×103 cfu·g-1～2.0×105 and 1.6×103～1.0×105 cfu·g-1,ammonifying bacteria fluctuated in 1.5×106～9.0×107 and 9.0×105～1.0×107 cfu·g-1,denitrifying bacteria fluctuated in 9.0×103～4.0×106 and 5.0×102～1.9×106 cfu·g-1,and sulphate reducing bacteria fluctuated in 5.0×104～5.0×106 and 1.9×104～2.0×106 cfu·g-1,respectively.The detection rates of ammonifying bacteria,denitrifying bacteria and sulphate reducing bacteria in the mud were all 100%,and these bacteria increased significantly in the second half of the year,indicating that the environment of the Sinonovacula constricta aquaculture area was deteriorated due to the accumulation of NH3,nitrite and H2S,and it is important to regulate the breed capacity and redistribute the breeding environment.

关键词： Sinonovacula constricta Tidal-flat area Heterotrophic bacteria Ammonifying bacteria denitrifying bacteria Sulphate reducing bacteria