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1.
为评估化肥配施有机肥对花生根际细菌群落的影响，田间试验条件下研究了不施肥(CK)、施化学氮磷钾肥(NPK)和化学氮磷钾肥+有机肥配施(NPKM)对花生根际细菌群落多样性、结构和共存网络的影响。结果表明：NPKM处理下花生根际土养分状况明显改善，特别是有效磷的含量，较CK和NPK处理分别提高了5.31倍～12.16倍和3.24倍～6.50倍；而NPK处理下花生根际土养分状况并没有明显提升；Source Tracker分析显示，NPKM处理下根际细菌群落中只有2.1%～5.5%的物种来源于有机肥自身，但其花生根际细菌群落多样性在生育期前期要明显高于CK和NPK处理，而CK和NPK处理下根际细菌群落多样性差异不大；限制性主成分分析(CAP)显示，施肥措施和生育期均对根际细菌群落结构产生了显著影响，NPKM处理下花生根际土中富集了属于根瘤菌目(Rhizobiales)、梭菌目(Clostridiales)和芽孢杆菌目(Bacillales)这一类根际促生菌，根际细菌共存网络结构更加复杂，且网络中重要连接点的比例要也明显高于CK和NPK处理网络。可见，化肥配施有机肥有助于构建一个健康稳定的根际细... 相似文献
2.
Addition of organic matter such as livestock manures and plant residues is a feasible practice to mitigate soil degradation caused by long-term application of chemical fertilizers, and the mitigation is largely mediated though activities of the soil-dwelling microorganisms. However, the roles of different kinds of organic matter in maintaining bacterial community structure have not been assessed in a comparative manner. In this study, 454 pyrosequencing of 16S rRNA gene was employed to compare the bacterial community structure among soils that had been subjected to 30 years of NPK fertilization under six treatment regimes: non-fertilization control, fertilization only, and fertilization combined with the use of pig manure, cow manure or low- and high-level of wheat straws. Consistent with expectation, long-term application of NPK chemical fertilizers caused a significant decrease of bacterial diversity in terms of species richness (i.e. number of unique operational taxonomic units (OTU)), Faith's index of phylogenetic diversity and Chao 1 index. Incorporation of wheat straw into soil produced little effects on bacterial community, whereas addition of either pig manure or cow manure restored bacterial diversity to levels that are comparable to that of the non-fertilization control. Moreover, bacterial abundance determined by quantitative PCR was positively correlated with the nutritional status of the soil (e.g., nitrate, total nitrogen, total carbon, available phosphorus); however, bacterial diversity was predominantly determined by soil pH. Together, our data implicate the role of livestock manures in preventing the loss of bacterial diversity during long-term chemical fertilization, and highlight pH as the major deterministic factor for soil bacterial community structure. 相似文献
3.
长期施肥对旱地红壤细菌群落的影响 总被引：13，自引：0，他引：13
为探讨长期不同施肥对旱地红壤细菌群落的影响,以中国农业科学院祁阳红壤实验站的冬小麦—夏玉米定位试验为研究对象,选取不施肥(CK)、单施氮肥(N)、施化学氮磷钾肥(NPK)和化学氮磷钾+有机肥配施(NPKM)4个处理,于试验开展25年(2015年)小麦收获后采集各处理0~20 cm的土壤样品,利用Illumina MiSeq高通量测序技术对土壤细菌群落进行测定,并深入揭示影响旱地红壤细菌群落的关键因素。结果表明:(1)长期不同施肥显著改变了旱地红壤的化学性质,N和NPK处理的土壤pH显著降低至4.02和4.15,而NPKM处理的土壤pH显著上升至5.99。NPK和NPKM处理均显著改善土壤肥力,但后者效果明显优于前者,而N处理对土壤肥力的提升效果微弱。(2)长期不同施肥改变了旱地红壤优势菌的相对丰度,非度量多维度分析(NMDS)和相似性分析(ANOSIM)表明不同处理的土壤细菌群落发生显著变化。(3)与CK相比,N处理的4种多样性指数(物种丰富度、Chao1指数、系统发育多样性和香农指数)显著降低了21.4%~49.4%,而NPKM处理显著增加了7.0%~66.9%,NPK处理也会使系统发育多样性和香农指数显著降低10.3%和13.0%。(4)逐步回归分析表明土壤pH是决定优势菌相对丰度及4种多样性指数的首要因素,多元回归树分析(MRT)探明土壤pH共解释了83.1%的细菌群落变异,不同处理间细菌群落转变均由土壤pH驱动。(5)STAMP分析发现,N、NPK和NPKM处理与CK分别有11、14和8个显著差异细菌属。综上所述,长期施肥后旱地红壤细菌群落主要受土壤pH的影响,而土壤肥力的作用相对较弱,长期施用化学氮肥造成的红壤酸化的负面效应已远超肥力改善的正面效应。因此,旱地红壤施肥应以防治土壤酸化为前提,长期化肥有机肥配施是一项适宜的施肥措施。 相似文献
4.
Soil Bacterial Communities Under Different Long-Term Fertilization Regimes in Three Locations Across the Black Soil Region of Northeast China 总被引：5，自引：0，他引：5
HU Xiaojing LIU Junjie WEI Dan ZHU Ping CUI Xi''an ZHOU Baoku CHEN Xueli JIN Jian LIU Xiaobing WANG Guanghua 《土壤圈》2018,28(5):751-763
Although soil bacteria play critical roles in agro-ecosystems, the knowledge of their response to long-term fertilization across the black soil region of Northeast China is limited. In this study, we sequenced 16 S rRNA genes to assess the effects of four long-term fertilization regimes—non-fertilization(NoF), chemical fertilizer(CF), manure(M), and chemical fertilizer plus manure(CFM)—on soil properties and bacterial communities in three locations, the northern, middle, and southern parts, across the black soil region. Results showed that the influence of fertilization regimes on soil properties varied significantly among the three locations. Manure fertilization significantly increased microbial biomass carbon and relative abundance of copiotrophic bacteria. Principal component analysis(PCA)showed that the total bacterial communities were separated into three groups according to the sampling location despite long-term fertilization, and that soil pH was the most important factor in shifting bacterial communities. In addition, similar fertilization regimes resulted in different influences on bacterial community composition, and the most influential soil properties varied among the three locations. Our results highlighted that geographical separation was a more dominant factor affecting bacterial communities than fertilization, and that long-term similar fertilization regimes did not induce consistent changes in bacterial community composition in the black soil region. 相似文献
5.
【目的】采用高通量测序和分子生态网络分析技术,研究连续施用化肥及秸秆还田对细菌群落结构和种间互作关系的影响,为黄淮海潮土区秸秆资源化利用与土壤肥力提升提供理论依据。【方法】长期定位试验位于山东德州,始于2010年,土壤为典型潮土,为冬小麦–夏玉米轮作。2021年从不施肥对照(CK)、单施化肥(NPK)和秸秆还田配施化肥(NPKS) 3个处理小区采集土壤样品,分析土壤养分、酶活性、细菌群落等指标。【结果】与CK处理相比,NPK和NPKS处理pH均降低了0.06个单位,土壤有机质分别提升了23.19%和34.82%,细菌多样性分别降低了0.90%和0.91%,均匀度均显著降低了1.11%。与CK相比,NPK处理土壤中β-葡糖苷酶(β-GC)和碱性磷酸酶(ALP)分别显著升高47.91%和50.35%,NPKS处理β-GC、ALP和脱氢酶(DHA)活性分别升高78.31%、46.53%和50.91%。CK处理的优势菌群为寡营养型细菌(酸杆菌门和浮霉菌门)和固氮菌(生丝微菌科和伯克氏菌科),NPK处理的优势菌群为可降解顽固有机质的变形菌门(草酸杆菌科、红丹杆菌科和黄单胞菌科)、放线菌门和拟杆菌... 相似文献
6.
长期有机无机肥配施对东北黑土真菌群落结构的影响 总被引：11，自引：5，他引：6
【目的】分析长期有机无机肥配施对土壤真菌丰度、多样性及其群落特征的影响,探讨东北黑土真菌群落变化与施肥的相关性,为进一步调节土壤微生物结构,改善其生态功能提供参考依据。【方法】依托黑龙江省农业科学院36年长期定位试验站,选取4个不同施肥处理:不施肥处理（CK）、有机肥处理（M）、氮磷钾无机肥处理（NPK）和有机肥配施无机肥处理（MNPK）的耕作层土壤为研究对象,以真菌ITS基因为分子标靶借助qPCR技术和Illumina Miseq高通量测序平台,研究不同施肥处理对黑土中真菌群落丰度、多样性和组成的影响,并与土壤化学性质进行偶联分析,揭示群落与施肥的相关性。【结果】长期施用无机肥显著降低土壤pH,而有机无机配施可以有效缓解土壤酸化。NPK处理的ITS基因丰度显著高于MNPK;MNPK处理的细菌/真菌比值（26.91104）显著大于NPK,各处理比值由高到低为MNPK M CK NPK。细菌/真菌比值与土壤pH正相关;MNPK处理的真菌多样性指数值略大于NPK。Ascomycota和Zygomycota为土壤中主要真菌门,不同施肥处理之间真菌组成的相对丰度存在显著差异,对照处理Ascomycota的相对丰度为45.35%,MNPK和NPK处理分别为50.93%和56.16%。有机肥有利于降低病原真菌相对丰度,具有高度侵染性的Cochliobolus在MNPK（0.41%）和M（0.39%）中的相对丰度显著小于CK（3.25%）和NPK（2.08%）。CCA分析表明,土壤理化性质共解释土壤真菌群落结构变化的73.3%,有效磷（贡献量为32.4%,P=0.002）、铵态氮（贡献量为14.8%,P=0.01）和硝态氮（贡献量为16.2%,P=0.048）是3个重要的影响因子。【结论】不同施肥条件下土壤真菌丰度、多样性,以及菌群组成特征不同。与无机肥相比,有机肥无机肥配施能够有效改善真菌群落结构,降低真菌的丰度,增加真菌多样性,并提高土壤pH,减缓土壤酸化。土壤有效磷、铵态氮和硝态氮含量是影响黑土土壤真菌群落结构变化重要因素。 相似文献
7.
Long-term fertilization regimes affect bacterial community structure and diversity of an agricultural soil in northern China 总被引：5，自引：2，他引：3
Yuan Ge Jia-bao Zhang Li-mei Zhang Min Yang Ji-zheng He 《Journal of Soils and Sediments》2008,8(1):43-50
Background, Aims, and Scope Knowledge about shifts of microbial community structure and diversity following different agricultural management practices
could improve our understanding of soil processes and thus help us to develop sound management strategies. A long-term fertilization
experiment was established in 1989 at Fengqiu (35°00′N, 114°24′E) in northern China. The soil (sandy loam) is classified as
aquic inceptisols and has received continuous fertilization treatments since then. The fertilization treatments included control
(CK, no fertilizer), chemical fertilizers nitrogen (N) and potassium (K) (NK), phosphorous (P) and K (PK), NP, NPK, organic
manure (OM), and half chemical fertilizers NPK plus half organic manure (1/2NPKOM). The objective of this study was to examine
if the microbial community structure and diversity were affected by the long-term fertilization regimes.
Materials and Methods Soil samples were collected from the long-term experimental plots with seven treatments and four replications in April 2006.
Microbial DNAs were extracted from the soil samples and the 16S rRNA genes were PCR amplified. The PCR products were analyzed
by DGGE, cloning and sequencing. The bacterial community structures and diversity were assessed using the DGGE profiles and
the clone libraries constructed from the excised DGGE bands.
Results The bacterial community structure of the OM and PK treatments were significantly different from those of all other treatments.
The bacterial community structures of the four Ncontaining treatments (NK, NP, NPK and 1/2NPKOM), as well as CK, were more
similar to each other. The changes in bacterial community structures of the OM and PK treatments showed higher richness and
diversity. Phylogenetic analyses indicated that Proteobacteria (30.5%) was the dominant taxonomic group of the soil, followed by Acidobacteria (15.3%), Gemmatimonadetes (12.7%), etc.
Discussion Irrespective of the two fertilization treatments of OM and PK, the cluster analysis showed that bacterial communities of the
remaining five treatments of CK, NK, NP, NPK and 1/2NPKOM seemed to be more similar to each other, which indicated the relatively
weak effects of the four N-containing treatments on soil bacterial communities. N fertilizer may be considered as a key factor
to counteract the effects of other fertilizers on microbial communities.
Conclusions Our results show that long-term fertilization regimes can affect bacterial community structure and diversity of the agricultural
soil. The OM and PK treatments showed a trend towards distinct community structures, higher richness and diversity when compared
to the other treatments. Contrasting to the positive effects of OM and PK treatments on the bacterial communities, N fertilizer
could be considered as a key factor in the soil to counteract the effects of other fertilizers on soil microbial communities.
Recommendations and Perspectives Because of the extremely high abundance and diversity of microorganisms in soil and the high heterogeneity of the soil, it
is necessary to further examine the effects of fertilization regimes on microbial community and diversity in different type
soils for comprehensively understanding their effects through the appropriate combination of molecular approaches.
ESS-Submission Editor: Chengrong Chen, PhD (c.chen@griffith.edu.au) 相似文献
8.
Fungal communities may have different response to fertilization under different conditions. Therefore, it is necessary to reveal the effects of fertilizations on fungal communities considering temporal heterogeneity at different crop stages. To address this, soil samples were collected across eight typical plant growth stages of a wheat-rice rotation system under four fertilization regimes: no nitrogen fertilizer (NNF), chemical fertilizer (CF), organic-inorganic mixed fertilizer (OIMF), and organic fertilizer (OF). Soil temperature and moisture that co-vary with plant growth stages were the strongest predictors of fungal community compositions; meanwhile, fertilization regimes also played important roles. Shannon index and the relative abundance of Ascomycota were consistently increased when compared OF treatment with CF and OIMF treatments, while CF treatment had a higher relative abundance of Zygomycota when compared with NNF and OF treatments. For the functional guilds, application of urea-nitrogen fertilizers (CF and OIMF treatments) significantly decreased the relative abundance of saprotrophs and symbiotrophs, while soil treated with OF had less relative abundance of pathotrophs when compared to inorganic fertilizers. Our study provided a detailed picture of how fungal community composition responded to fertilization regimes across different plant growth stages. 相似文献
9.
土壤微生物群落稳定性是土壤健康的重要组成部分和评价指标，揭示长期不同施肥的农田土壤微生物群落稳定性有助于指导田间施肥管理，保障农田生态系统的土壤健康和可持续发展。本研究依托中国科学院封丘农业生态实验站长期定位试验，通过对三种不同施肥处理的潮土进行干旱扰动和复水回复的培养试验，从多种微生物群落响应指标（脱氢酶活性、细菌群落alpha多样性、关键物种丰度、微生物群落结构和分子生态网络拓扑属性）分别量化和比较了不同施肥处理的微生物群落稳定性（抵抗力和回复力）。结果表明，与不施肥处理（CK）和平衡施用化肥处理（NPK）相比，有机无机肥配施处理（OM）能够显著增加微生物群落稳定性，表现在OM的微生物群落响应指标在干旱-复水过程中的变化最小，抵抗力与回复力均优于CK和NPK。复水后不同施肥处理的细菌群落alpha多样性、关键物种丰度和网络拓扑参数能够回复到初始水平，而群落结构和脱氢酶活性不能完全回复，说明细菌群落alpha多样性的回复快于群落结构和功能。本文基于多种微生物群落响应指标定量计算微生物群落的抵抗力和回复力，结果表明有机无机肥配施能显著提高微生物群落稳定性，是保障农田生态系统土壤健康和可持续发展的优良管理措施。 相似文献
10.
探究不同植物残体还田条件下微生物关键种如何影响木质素酚的浓度(木质素酚与土壤有机碳的比值),旨在为不同有机物料还田培肥土壤提供理论和技术依据。本研究以河西绿洲灌区的灌漠土作为研究对象,开展了30 a以施加绿肥(GM)、小麦秸秆(SW)、氮肥(N)、绿肥配施氮肥(GMN)、小麦秸秆配施氮肥(SWN)以及不施肥(CK) 6种不同施肥处理的培肥试验。结果表明:GM和SW处理的土壤有机碳含量显著高于其他处理;有小麦秸秆参与还田的处理显著提高了总木质素酚浓度以及3种木质素酚类单体的浓度,其中总木质素酚浓度在SW处理中分别比CK、GM、N、GMN和SWN处理高了109%、122%、115%、164%和57%;对比不施肥和施化肥处理,植物残体还田显著提高了微生物关键种F3(盘菌纲,Pezizomycetes)、F26(被孢霉菌纲,Mortierellomycetes)、F173(粪壳菌纲,Sordariomycetes)、B74(阿尔法变形菌纲,Alphaproteobacteria)和B87(放线菌纲,Actinobacteria)的相对丰度。本研究共鉴定出15个关键种,其中关键种B831(属阿尔... 相似文献
11.
长期有机与无机肥配施的黄壤稻田土壤细菌群落结构特征 总被引：1，自引：1，他引：0
12.
不同施肥模式对土壤氮循环功能微生物的影响 总被引：3，自引：1，他引：2
[目的]微生物在土壤氮循环过程中发挥着重要作用.通过研究农田土壤氮循环过程中不同功能微生物群落基因丰度对施肥模式的响应及其关键影响因素,探讨不同施肥模式调控下氮素转化的微生物学机制,为改善农业生产中氮素的管理策略提供理论依据.[方法]田间试验始于2011年,试验地点位于江苏省常州市溧阳市南渡镇,供试土壤为白土型水稻土,... 相似文献
13.
Biological input of nitrogen (N) from the atmosphere by free-living diazotrophs can help alleviate fertilizer use in agricultural systems. In this study, we investigated the effect of N fertilizer and winter pea (Pisum sativum L.) crop on the community structure and abundance of free-living diazotrophs in a two year study of dryland winter wheat (Triticum aestivum L.) no-till production system in Eastern Oregon, USA. Based on quantification of the nifH gene, diazotroph abundance was strongly influenced by plant species and the crop year in which the soil samples were collected. A greater amount of nifH copies was recovered in 2012 compared to 2011 either as copies per gram soil or normalized to the abundance of bacterial 16S rRNA genes. The quantity of genes was greater under pea than wheat in 2012 although no difference was observed in the preceding year. The nifH gene abundance was positively correlated to ammonium concentration in 2011 and bacterial abundance in 2012. Nitrogen application did not influence diazotroph abundance in the top 0–5 cm; however the abundance was reduced by application at the lower 5–10 cm depth under wheat crop. The diazotroph community structure appeared to be influenced more by N fertilization rather than plant species with the exception of wheat in 2012. Changes in the community structure over the two years were greater for fertilized than unfertilized soil. Collectively, these data suggest that year-to-year variability had a greater influence on diazotroph communities rather than specific parameters of plant species, fertilization, total N, total organic C, or soil pH. Multi-year studies are necessary to define the specific drivers of diazotroph abundance, community structure and function. 相似文献
14.
施肥模式对晚稻田杂草群落的影响 总被引：3，自引：0，他引：3
【目的】长期不合理施化肥对生态环境的影响已经引起学者和公众的关注,有机肥的施用越来越受到重视。揭示有机肥对农田杂草群落影响的机制、预测有机农业环境下杂草群落的演替趋势十分困难。本文对比研究不同施肥模式下农田杂草的群落特征,探索晚稻田杂草群落结构演变趋势,以期为现代农业中有机肥的合理施用和农田生物多样性保护提供科学依据。【方法】通过田间长期定位施肥试验,运用群落生态学方法研究了晚稻种植季五种施肥处理区杂草群落的结构特征及其生物多样性。在每个小区随机设置5个面积为0.25 m2的样方,记录各样方内杂草物种种类、每个种类杂草的数量,调查杂草的盖度与频度;测定稻谷理论产量;使用照度计测量地表与水稻冠层顶部的光照强度,计算光照透过率;测定耕作层土壤的有机质、碱解氮、有效磷、速效钾含量。计算杂草的重要值,采用物种丰富度(S)和Shannon-Wiener指数(H)测定杂草群落的生物多样性;以15个处理小区中的11种常见杂草的重要值构成原始数据矩阵,应用SPSS16.0软件进行主成分分析和典范对应分析。【结果】晚稻田不同施肥处理土壤养分以及光照透过率差异显著,施有机肥的处理晚稻稻谷产量高于CK与NPK纯化肥处理。CK处理区优势种为野荸荠-节节菜-异型莎草-鸭舌草,NPK处理区优势种为双穗雀稗,NPK5/5和NPK3/7处理区优势种为双穗雀稗-鸭舌草,NPK7/3处理区优势种为双穗雀稗-鸭舌草-稗。主成分分析结果表明15个施肥处理小区的杂草群落可以分为三大类:第一类是CK处理;第二类是NPK3/7处理;第三类是NPK、NPK5/5、NPK7/3三个处理。主成分Factor 1与有机质、碱解氮以及有效磷呈极显著负相关(P0.01),与光照透过率呈极显著正相关(P0.01)。典范对应分析结果显示,节节菜、野荸荠与牛毛毡比较适宜生长在CK处理区,双穗雀稗适宜在NPK7/3处理区生长,鸭舌草、陌上菜以及四叶萍适宜生长在NPK3/7处理区。有机肥处理区的物种丰富度与物种多样性指数处于NPK与CK之间,且随着有机肥比例的增加物种数增加。物种丰富度以及物种多样性指数与有机质、碱解氮以及有效磷呈极显著正的"U型"相关(P0.01),与速效钾呈显著负相关(P0.05),与群落光照条件呈极显著正相关(P0.01)。【结论】晚稻田杂草群落特征与土壤有机质、碱解氮、有效磷含量以及地表光照透过率关系密切。均衡施用有机和无机肥可以显著降低杂草群落的优势种数量,将杂草群落的优势种数量以及生物多样性维持在不施肥与纯施化肥处理区之间。因此,可以通过调整有机肥的施用量来调控农田杂草生长及群落特性,实现农田杂草的科学综合管理。综合考虑晚稻稻谷产量和杂草群落生物多样性状况,NPK3/7(化肥30%+有机肥70%)施肥模式既可以保证作物的优质高产,也可以较好地维持杂草群落的生物多样性。 相似文献
15.
采用田间试验研究了牛粪、化肥单施和配施对萝卜产量,菜体硝酸盐累积、分布、同化,及土壤硝态氮含量变化的影响。结果表明,牛粪、化肥单施和配施,萝卜产量动态变化依次为FOM(1/2化肥+1/2牛粪)、OM(牛粪)F(化肥)CK(无肥),叶部和肉质根硝酸盐含量高低依次为FFOMCKOM,粗蛋白累积量依次为FFOMCKOM,土壤硝态氮含量动态变化依次为FFOMOMCK。综合各因素总体以化肥配施牛粪最为适中,若重点考虑食用安全和土壤硝态氮累积环境效应,则以单施牛粪表现为最佳,各处理引起硝酸盐富集和土壤硝态氮残留的风险依次为化肥(1/2化肥+1/2牛粪)牛粪。萝卜硝酸盐含量分布表现为叶部生长旺盛期叶部硝酸盐含量高于肉质根,肉质根生长旺盛期地下部将贮存更多的硝酸盐。在地上部,当植株硝酸盐富集时,硝酸盐累积在内叶和叶柄中;当植株生长处于养分"饥饿"状态时,硝酸盐释放到外叶和叶片中。因此,菜地连续施用有机肥,不仅可减少蔬菜对硝酸盐的富集,且可维持后期蔬菜产量。 相似文献
16.
长期不同施肥措施下塿土细菌群落结构变化及其主要影响因素 总被引：2，自引：0，他引：2
17.
【目的】依据黑龙江省农科院34年的长期定位试验,探讨影响东北黑土细菌和古菌区系的主效环境因子。【方法】试验采集不施肥(CK)、施氮磷肥(NP)、施氮钾肥(NK)、施磷钾肥(PK)、施氮磷钾肥(NPK)5个施肥处理的耕层土样借助传统化学分析方法和Illumina Miseq高通量测序技术解析土壤化学性状和细菌与古菌的群落结构特征,并对细菌和古菌群落结构与环境因子进行相关性分析。【结果】1)不同施肥处理土壤细菌和古菌群落结构存在显著差异与CK相比,4种施肥处理均降低了古菌丰富度,NPK处理增加了土壤细菌的丰富度、多样性以及古菌的多样性;变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)是所有土样中的优势菌群,占细菌与古菌总量的38.2%~42.9%。施肥条件下,放线菌门(Actinobacteria)、浮霉菌门(Planctomycetes)、绿弯菌门(Chloroflexi)、蓝藻门(Cyanobacteria)的相对丰度降低芽单胞菌门(Gemmatimonadetes)、厚壁菌门(Firmicutes)的相对丰度升高而其他菌门的相对丰度对不同施肥处理的响应不同。2)施用氮肥显著改变了土壤化学性状,长期施氮(尿素)处理的土壤全氮、速效氮和有机质含量显著高于不施氮处理而pH则显著降低。3)RDA分析结果显示,pH对土壤细菌和古菌群落结构的影响最大解释了66.5%的变化;其他环境因子则共解释了细菌与古菌群落33.5%的变化各因子的贡献率依次为pH速效钾有效磷有机质。Pearson相关性分析结果也表明,细菌和古菌群落与土壤化学指标间存在密切的相关关系。【结论】解析了长期不同施肥条件下土壤细菌和古菌的群落结构特征,确定了pH是影响土壤细菌和古菌区系的主效环境因子,氮磷钾均衡施肥不仅显著提高了作物产量和丰富了土壤养分含量,同时也增加了土壤细菌的丰富度、多样性以及古菌的多样性,有利于维持良好的土壤生态环境。研究结果对揭示东北黑土肥力演变机制、建立合理的施肥制度具有重要的理论价值。 相似文献
18.
Nematode body size is a trait that could be responsive to environmental changes, such as agricultural management practices, and adopted as a standard trait-based indicator in soil community analysis. Our study investigated how body size in the nematode community responded to fertilization in a double-cropping system with paddy rice and upland wheat. Four fertilizer treatments were examined: an unfertilized control (CK), chemical fertilizer (CF), manure plus chemical fertilizer (MCF) and manure plus straw plus chemical fertilizer (MSCF). The community-weighted mean (CWM) of body size was the trait-based indicator used for nematode community analysis. A trend of increasing body size in fertilized plots was observed for most genera, with a relatively small increase in the size of small-bodied bacterivores and fungivores and a relatively large increase in the size of large-bodied omnivores. Fertilized plots had significantly greater CWM of body size than the CK treatment, although total nematode abundance increased significantly in the MSCF treatment only. Discriminant and multiple regression analyses showed that CWM of body size was positively correlated with the soil organic C, total N, available P and available K concentrations, which responded to fertilizer inputs. In contrast, soil fertility was weakly related to total body size in the wheat phase and the following abundance-based indicators: Margalef's richness index, Shannon's diversity index, summed maturity index (∑MI) and enrichment index (EI) in both phases. Since fertilization resulted in larger body size but no other change in the nematode community (i.e. diversity and abundance were generally unaffected by fertilization), this implies that nematodes have a plastic growth habit that does not necessarily result in greater reproduction or fitness of offspring. We suggest that CWM of body size is a reliable trait-based indicator of the soil nematode community response to fertilization, but this requires further testing across a wider range of fertilized agroecosystems. 相似文献
19.
The effects of long-term fertilization of acidic soils on ammonia-oxidizing archaea (AOA) and bacteria (AOB) communities and its ecological implications remain poorly understood. We chose an acidic upland soil site under long-term (27-year) fertilization to investigate ammonia oxidizer communities under four different regimes: mineral N fertilizer (N), mineral NPK fertilizer (NPK), organic manure (OM) and an unfertilized control (CK). Soil net nitrification rates were significantly higher in OM soils than in CK, N or NPK soils. Quantitative analysis of the distribution of amoA genes by DNA-based stable isotope probing revealed that AOA dominate in CK, N and NPK soils, while AOB dominate in OM soils. Denaturing gradient gel electrophoresis and clone library analyses of amoA genes revealed that Group 1.1a-associated AOA (also referred to as Nitrosotalea) were the most dominant active AOA population (>92%), while Nitrosospira Cluster 3 and Cluster 9 were predominant among active AOB communities. The functional diversity of active ammonia oxidizers in acidic soils is affected by long-term fertilization practices, and the responses of active ammonia oxidizers to mineral fertilizer and organic manure are clearly different. Our results provide strong evidence that AOA are more highly adapted to growth at low pH and low substrate availability than AOB, and they suggest that the niche differentiation and metabolic diversity of ammonia oxidizers in acidic soils are more complex than previously thought. 相似文献
20.
Yunfu Gu Xiaoping Zhang Shihua Tu Kristina Lindström 《European Journal of Soil Biology》2009,45(3):239-246
Soil microbial biomass carbon (SMBC) and nitrogen (SMBN), soil microbial community structure, and crop yields were studied in a long-term (1982–2004) fertilization experiment carried out in Suining, Sichuan province of PR China. Eight treatments included three chemical fertilizer (CF) treatments (N, NP, NPK), three CF + farmyard manure (M) treatments (NM, NPM, NPKM), M alone and no fertilizer (CK) as control. The results showed that the soil microbial biomass was higher in soil treated with CFM than in soil treated with CF alone, and that NPKM gave the highest rice and wheat yields. The SMBC and SMBN were higher after rice than those after wheat cropping. SMBC correlated closely with soil organic matter. Average yields of wheat and rice for 22 years were higher and more stable in the fertilized plots than in control plots. Bacterial community structure was analyzed by PCR-DGGE targeting eubacterial 16S rRNA genes. A higher diversity of the soil bacterial community was found in soil amended with CFM than in other fertilizer treatments. Some specific band emerged in the soil amended with M. The highest diversity of bacterial communities was found in the NPKM treated soil. The bacterial community structures differed in rice and wheat plots. Sequencing of PCR products separated in DGGE showed that some of the common and dominant bands were closely related to Aquicella lusitana and to Acidobacteria. This study demonstrated that mixed application of N, P, and K with additional M amendment increased soil microbial biomass, diversified the bacterial communities and maintained the crop production in the Calcareous Purplish Paddy soil. 相似文献