,1Short-Term Effect of Biochar Amendments on Total Bacteria and Ammonia Oxidizers Communities in Different Type Soils
ZHANG MengYang1, XIA Hao1, Lü Bo1, CONG Ming1, SONG WenQun2, JIANG CunCang,1通讯作者:
收稿日期:2018-09-10接受日期:2018-10-29网络出版日期:2019-04-01
| 基金资助: |
Received:2018-09-10Accepted:2018-10-29Online:2019-04-01
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张梦阳,Tel：027-87287141;E-mail：
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张梦阳, 夏浩, 吕波, 丛铭, 宋文群, 姜存仓. 短期生物炭添加对不同类型土壤细菌和氨氧化微生物的影响[J]. 中国农业科学, 2019, 52(7): 1260-1271 doi:10.3864/j.issn.0578-1752.2019.07.013
ZHANG MengYang, XIA Hao, Lü Bo, CONG Ming, SONG WenQun, JIANG CunCang.
0 引言
【研究意义】氮是组成生命最重要物质核酸和蛋白质必不可少的元素之一[1],土壤圈是氮循环中最活跃的区域,土壤中氮循环对土壤质量、农业生产力乃至其他地球化学循环都有着重要的作用,而微生物是必不可少的推动者[2,3]。生物炭近年来被广泛应用于改良土壤、提高土壤固炭能力等[4],但生物炭施用于不同土壤时改良效果不同 [5],生物炭在土壤中的具体微生物效应也不明确。因此,研究生物炭对不同类型土壤微生物群落和氨氧化作用在农业生产中意义重大。【前人研究进展】生物炭作为一种土壤改良剂,郑瑞伦等[6]的研究表明,400℃热解得到的秸秆炭施用于壤土中显著改善土壤pH、通气性、含水量、有效养分等。李昌见等[7]通过大田试验也发现施用10 t·hm-2到60 t·hm-2玉米秸秆炭都显著提高了砂壤土的含水量、肥料利用率。吕波等[8]施加3%生物炭后发现红壤和黄棕壤的pH、速效养分以及酶活性都得到显著提高。应介官等[9]研究也表明在红壤中添加生物炭可以显著降低土壤铝毒。相应研究也证明了在不同温度下热解得到的生物炭都不同程度降低营养物质的淋失,ASADA等[10,11]研究表明,低温（400—500℃）热解产生的毛竹生物炭有更强的NH3吸附能力。CLOUGH等[12]发现,高于600℃热解产生的木材生物炭才具有较好的NO3-吸附能力。前人研究也发现生物炭的施用也与温室气体的排放有关,有****利用9种不同原料经500℃热解得到的生物炭,研究了它们在14种不同类型土壤中N2O的排放,结果表明施用生物炭提高了土壤pH,从而减少土壤中N2O的排放[13],但也有研究发现施用600℃热解得到的木质生物炭对草地土壤N2O排放无影响[12],甚至有研究者发现无论是高温（900℃）生产的核桃炭还是中温（550℃）生产松木炭都促进砂质黏壤土N2O的排放[14]。氨氧化作用为硝化作用的限速步骤,该作用主要由氨氧化微生物推动,氨氧化细菌广泛的分布在土壤生态系统、淡水生态系统和海洋生态系统中,且氨氧化细菌主要属于β变形菌纲和γ变形菌纲[15,16]。氨氧化古菌的发现让我们了解到参与氨氧化作用的不仅有细菌还有古菌。最初,人们认为氨氧化古菌隶属于温泉古菌（Crenarchaeota）[17],BROCHIERARMANET等[18]研究并提出了新的古菌菌门奇古菌门（Thaumarchaeota）。也有研究证明奇古菌几乎包括了所有发现的土壤、海洋、热泉中的氨氧化古菌[19]。目前来看,生物炭对土壤氮循环的影响已开展较多研究,并发现生物炭的添加可能影响着氮素淋溶、氨挥发、硝化作用、固氮作用、以及氧化亚氮的产生[20,21,22,23,24],微生物驱动土壤氮循环的各过程[2,3]。我们可以明确土壤类型差异是导致生物炭施用效果差异产生的主要原因之一。ABUJABHAH等[25]也发现热解温度为650—750℃的桉树生物炭对土壤微生物群落和氮循环细菌的影响主要取决于土壤类型,其中对红壤和黑土的作用明显高于棕壤。LIU等[26]施用了0—40 t·hm-2的稻壳生物炭（400℃）于红壤、棕壤和盐渍土中,结果发现生物炭对红壤细菌群落改变最显著。【本研究切入点】在不同土壤中驱动土壤氨氧化作用的主要微生物可能是氨氧化细菌也可能是氨氧化古菌,但生物炭的添加究竟是改变了土壤中氨氧化细菌的丰度还是氨氧化古菌的丰度;在不同土壤施用生物炭后氨氧化微生物的变化趋势是否相同;生物炭对酸碱性不同的土壤造成的氨氧化微生物的具体差异是否相同,很多类似的问题仍没有明确的答案。【拟解决的关键问题】本文选取我国3种不同类型土壤（黄棕壤、潮土、黑土）为供试土壤,通过16S rRNA测序分析得到单一施炭、单一施肥、生物炭与化肥同施对不同类型土壤细菌群落结构、氨氧化微生物丰度以及氮代谢通路中相关酶基因表达量的具体差异,从而揭示生物炭对不同土壤细菌群落和氨氧化作用的具体影响,为生物炭的实际应用提供理论依据。1 材料与方法
1.1 样本采集及试验处理
试验土壤采集湖北黄棕壤、山东潮土、黑龙江黑土,每个地区选择100 m2的区域,在区域中随机选择10个采样点采集0—20 cm土层的土壤样品,分别代表酸性、弱酸性和碱性土壤（供试土壤基本性质见表1）。样品自然风干后挑去石子、植物根系等杂物,全部研磨过2 mm筛,混匀后储存备用。设4个处理：CK（不施用化肥和生物炭）,F（单施化肥）,C（单施生物炭）,FC（施用化肥+生物炭）。化学肥料施用KH2PO4,KNO3,NH4NO3和Ca(NO3)2（其中N 0.46 g·kg-1干土,P2O5 0.07 g·kg-1干土,K2O 0.24 g·kg-1干土）。沈阳农业大学提供花生壳生物炭,生物炭在400℃下热解制备而成,全炭321.9 g·kg-1,全氮18.8 g·kg-1,全磷2.6 g·kg-1,全钾8.5 g·kg-1,生物炭施用量为2%（生物炭质量/土壤质量）。试验在塑料杯中进行培养,每杯装土300 g,根据试验方案加入化肥和生物炭并混匀,土壤上层平铺一层滤纸防止浇水时扰动土壤,每个处理设置3次重复,试验过程中土壤持水量保持在40%左右。土壤与肥料和生物炭按处理混匀后加水至饱和持水量,静置熟化1周,熟化后培养4周,试验于2018年5月6日至6月1日在华中农业大学盆栽场进行。试验结束后采集新鲜土壤于-80℃保存用于DNA的提取以及测定,其余土壤自然风干后,过1 mm筛,用于测定土壤pH（液土比例为2.5:1）。Table 1
表1
表1供试土壤的基本性质
Table 1
| 土壤类型 Soil type | 质地 Soil texture | pH | 碱解氮 Available nitrogen (mg·kg-1) | 速效磷 Available phosphorus (mg·kg-1) | 速效钾 Available potassium (mg·kg-1) | 有机质 Organic matter (g·kg-1) |
|---|---|---|---|---|---|---|
| 黄棕壤Yellow-brown soil (YB) | 黏土Clay | 5.2 | 77.7 | 49.2 | 169.4 | 13.3 |
| 潮土Fluvo-aquic soil (FA) | 壤土Loam | 5.6 | 43.9 | 9.3 | 84.7 | 8.7 |
| 黑土Black soil (B) | 黏土Clay | 8.8 | 125.5 | 3.6 | 259.2 | 32.5 |
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1.2 DNA 抽提和PCR扩增
根据E.Z.N.A.? soil试剂盒 （Omega Bio-tek,Norcross,GA,U.S.）说明书进行总DNA抽提,DNA浓度和纯度利用NanoDrop2000进行检测,利用1%琼脂糖凝胶电泳检测DNA提取质量;用515F（5′-GT GCCAGCMGCCGCGG-3′）和806R（5′-GGACTACH VGGGTWTCTAAT-3′）引物对V4可变区进行PCR扩增。1.3 Illumina Miseq 测序
使用2%琼脂糖凝胶回收PCR产物,利用AxyPrep DNA Gel Extraction Kit（Axygen Biosciences,Union City,CA,USA）进行纯化,Tris-HCl洗脱,2%琼脂糖电泳检测。利用QuantiFluor?-ST（Promega,USA）进行检测定量。根据Illumina MiSeq 平台（Illumina,San Diego,USA）标准操作规程将纯化后的扩增片段构建PE 2*300的文库。1.4 数据处理
原始测序序列使用Trimmomatic 软件质控,使用FLASH软件进行拼接[27]：（1）设置50 bp的窗口,如果窗口内的平均质量值低于20,从窗口前端位置截去该碱基后端所有序列,之后再去除质控后长度低于50 bp的序列;
（2）根据重叠碱基overlap将两端序列进行拼接,拼接时overlap之间的最大错配率为0.2,长度需大于10 bp。去除无法拼接的序列。
（3）根据序列首尾两端的barcode和引物将序列拆分至每个样本,barcode需精确匹配,引物允许2个碱基的错配,去除存在模糊碱基的序列。
本研究使用UPARSE软件（version 7.1
采用Microsoft Excel 2010对数据整理,用SPSS 20.0软件进行单因素方差和多因素分析,ANOVA进行显著性差异比较,多重比较采用Duncan检验,所有数值均为3次重复的平均值。
2 结果
2.1 生物炭对不同土壤pH的影响
图1所示,在黄棕壤中施用生物炭后显著提升了其土壤的pH,提升了0.6—1.0个单位,然而单一施用化肥并未产生显著性差异。在潮土中施用生物炭pH提升了0.5—0.6个单位,而仅施用化肥时降低了0.3个单位。在黑土中,与CK相比,无论是施用生物炭还是化肥都造成了土壤pH的显著降低,降幅为0.2—0.6个单位。通过三因素方差分析发现,无论单一施肥、单一施炭还是生物炭与化肥同施都对土壤pH产生显著影响,另外三因素两两间的交互效应也对土壤pH存在显著影响,但三因素间的交互效应并无显著影响（表2）。图1
新窗口打开|下载原图ZIP|生成PPT图1不同处理条件下不同土壤的pH
YB：黄棕壤;FA：潮土;B：黑土。CK,F,C,FC分别代表对照,单施化肥,单施生物炭和生物炭与化肥同施4种处理。图柱上不同字母表示在处理间存在显著差异（P<0.05）。下同
Fig. 1The pH of different soil under different treatment conditions
YB: Yellow-brown soil; FA: Fluvo-aquic soil; B: Black soil. CK, F, C, FC represent control treatment, single application of chemical fertilizer, single application of biochar and combined application of biochar and chemical fertilizer, respectively. Different letters indicate significant differences between treatments (P<0.05). The same as below
Table 2
表2
表2土壤pH三因素方差分析
Table 2
| 因素Factor | F | P value |
|---|---|---|
| 单施化肥处理F treatment | 38.379 | 0.000 |
| 单施生物炭处理C treatment | 271.157 | 0.000 |
| 土壤类型Soil type | 4304.294 | 0.000 |
| F×C | 11.815 | 0.002 |
| F×Soil type | 57.887 | 0.000 |
| C×Soil type | 121.239 | 0.000 |
| F×C×Soil type | 0.204 | 0.817 |
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2.2 生物炭对不同土壤细菌、古菌丰富度和多样性指数的影响
本研究采用Ace指数和Shannon指数表示微生物丰富度指数以及多样性指数,与对照相比分析经化肥或生物炭处理后的指数变化（图2）。在黄棕壤中单施生物炭提升了土壤细菌和古菌的丰富度和多样性,且与对照、单施化肥处理之间存在显著性差异,单施化肥降低了黄棕壤的丰富度和均匀度指数,但无显著性差异,经炭肥同施后也并未出现显著变化（图2-a,图2-b）。在潮土中,单施化肥降低了土壤细菌和古菌的丰富度和多样性,但仅在丰富度指数上存在显著性差异,单施生物炭后细菌和古菌的多样性指数得到显著提升,生物炭与化肥同施后细菌和真菌的丰富度和多样性指数变化幅度均较小（图2-c,2-d）。在黑土中,不同处理对土壤细菌和古菌丰富度和多样性指数未出现显著性改变（图2-e,2-f）。图2
新窗口打开|下载原图ZIP|生成PPT图2不同土壤中各处理间Alpha指数组间差异检验柱状图
*代表在0.05水平下差异显著,**代表在0.01水平下差异显著
Fig. 2Histogram of difference between Alpha index groups in different soils
*Represents a significant difference at the 0.05 level, **Represents a significant difference at the 0.01 level
2.3 生物炭对不同土壤氨氧化微生物丰度的影响
通过分析测序所得氨氧化微生物的OTU丰度发现,无论是在黄棕壤还是在潮土和黑土中,氨氧化细菌的OTU丰度远大于氨氧化古菌的OTU丰度。另外,氨氧化古菌经处理后测得的OTU丰度差异性不显著,而氨氧化细菌在处理后则出现了显著性差异（表3）。Table 3
表3
表3氨氧化微生物OTU丰度
Table 3
| 处理 Treatment | 奇古菌Thaumarchaeota | β和γ变形菌β, γ- Proteobacteria | ||||
|---|---|---|---|---|---|---|
| YB | FA | B | YB | FA | B | |
| CK | 152a | 216a | 763a | 4768ab | 6156ab | 2141ab |
| F | 285a | 194a | 873a | 4744ab | 5726b | 1937b |
| C | 219a | 63a | 1259a | 3997b | 6626a | 1918b |
| FC | 130a | 110a | 1121a | 5267a | 6417a | 2969a |
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为进一步了解土壤中氨氧化微生物丰度的变化趋势,针对古菌中的奇古菌和细菌中的β变形菌和γ变形菌的丰度变化进行了分析（图3）。结果显示,在黄棕壤氨氧化古菌丰度变化上,奇古菌门在单施化肥和单施生物炭后分别提升了约81.8%和45.6%,但在生物炭与化肥同施时,其丰度下降了约15.0%（图3-a）。在氨氧化细菌丰度变化上,主要以β变形菌为主,约占92.3%。β和γ变形菌之和以生物炭与化肥同施处理最高,与对照相比提高了14.8%,而单施生物炭却降低了18.0%（图3-b）。在潮土中,所有处理对土壤奇古菌门的丰度均存在降低作用,其中施炭处理（F和FC）的降低趋势最明显,分别降低了70.5%和48.7%（图3-c）。另外,潮土中氨氧化细菌主要以β变形菌为主（图3-d）。与潮土不同的是,黑土中所有处理对奇古菌门的丰度都存在提升趋势,其中施炭处理（F和FC）提升最明显,分别提高了66.7%和48.1%（图3-e）。在氨氧化细菌方面,虽然黑土也以β变形菌为主,但是γ变形菌的丰度比例远高于其余潮土和黄棕壤。另外,在炭肥同施时黑土中氨氧化细菌的丰度也出现较大幅度的升高（图3-f）。
图3
新窗口打开|下载原图ZIP|生成PPT图3不同土壤各处理间奇古菌,β变形菌和γ变形菌的丰度变化柱状图
Fig. 3Histogram of abundance changes of thaumarchaeota, betaproteobacteria and gammaproteobacteria in different soil
2.4 生物炭对不同土壤细菌、古菌群落结构的作用
通过主成分分析细菌和古菌的β多样性,进一步探究各处理间群落结构的差异（图4）。在黄棕壤中,单施化肥样本点与对照样本点分离程度较低,表明单施化肥对土壤的细菌和古菌的群落结构影响较小。施炭处理（C和FC）与对照在X轴（40.4%）上存在明显分离,另外单施炭和炭肥同施在Y轴（19.5%）上也存在明显的分离（图4-a）。在潮土中,施炭处理（C和FC）样本点皆分布在第四象限,与对照处理在X轴（42.3%）和Y轴（21.3%）上都存在明显分离（图4-b）。在黑土中,对照、单施化肥以及炭肥同施三者之间没有出现明显的分离,但是单施化肥样本点与对照样本点间距离相对较远,说明在黑土中单施化肥对土壤细菌和真菌群落结构的影响相对较大（图4-c）。图4
新窗口打开|下载原图ZIP|生成PPT图4不同土壤各处理间主成分分析
Fig. 4Principal component analysis of each soil treatment
2.5 生物炭对土壤氨合成相关酶和氨氧化作用相关酶基因表达量的影响
土壤中氮素循环过程中需要通过各个支路中各种各样的酶相互协调完成（图5,数据网址：http://www. genome.jp/kegg/pathway.html）。根据氮素代谢通路丰度表可以发现,黄棕壤和黑土经化肥或生物炭处理后氮素代谢通路丰度并未发生显著性改变,但在潮土中添加生物炭后氮素代谢通路丰度出现显著性降低（表4）。图5
新窗口打开|下载原图ZIP|生成PPT图5KEGG氮素代谢通路
Fig. 5KEGG metabolic pathway of nitrogen metabolism
Table 4
表4
表4不同土壤各处理的氮代谢通路丰度
Table 4
| 土壤类型Soil type | CK | F | C | FC |
|---|---|---|---|---|
| YB | 260856a | 250203a | 238879a | 230877a |
| FA | 263525a | 253256ab | 242993bc | 234804c |
| B | 225273a | 220124a | 223533a | 226165a |
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根据氮素代谢通路图可以得到与氮素代谢相关酶和基因的对应关系,并通过比对数据库得到一些与氨合成和氨氧化作用相关酶的相关表达（表5）。分析氮素代谢通路中相关酶基因表达量,研究在不同土壤不同处理中相关酶的变化情况,发现检测到的酶在黑土中出现变化的较少,只有甲酰胺酶（1.7.2.1）和腈水解酶（3.5.1.49）在处理间存在显著差异。然而在黄棕壤和潮土中存在显著差异的酶数量明显多于黑土,且不同土壤间经化肥或生物炭处理后出现显著性差异的酶的种类也存在明显区别。
Table 5
表5
表5土壤氨合成相关酶和氨氧化作用相关酶基因表达量
Table 5
| 酶 Enzyme | EC（编号）EC (number) | YB | FA | B | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CK | F | C | FC | CK | F | C | FC | CK | F | C | FC | ||
| 甲酰胺酶 Formamidase | 1.7.2.1 | 1073a | 1384a | 1014a | 1083a | 1077a | 1069a | 892a | 933a | 361b | 328b | 329b | 477a |
| 腈水解酶 Nitrilase | 3.5.1.49 | 4513ab | 5000a | 4044b | 4582ab | 5402a | 6062a | 5352a | 5025a | 5849a | 5448a | 5232a | 6008a |
| 氰酸裂合酶 Cyanate lyase | 3.5.5.1 | 7036ab | 7303ab | 5903b | 7985a | 9535a | 8958a | 9566a | 9398a | 9240ab | 8538bc | 8168c | 9710a |
| 氨基甲酸酯激酶 Carbamate kinase | 4.2.1.104 | 4006ab | 3632b | 3521b | 4448a | 4539a | 4761a | 4592a | 4837a | 4657a | 4547a | 4384a | 4533a |
| 谷氨酸脱氢酶 Glutamate dehydrogenase | 2.7.2.2 | 4984ab | 5332a | 4574ab | 4200b | 5148a | 5068a | 3263b | 3092b | 9561a | 9745a | 10561a | 10095a |
| 谷氨酸脱氢酶(NAD(P)+) Glutamate dehydrogenase ((NAD(P)+) | 1.4.1.2 | 9631ab | 10188a | 8444b | 9389ab | 10659a | 11757a | 8684b | 8277b | 17594a | 16898a | 16405a | 16705a |
| 谷氨酸脱氢酶(NADP+) Glutamate dehydrogenase (NADP+) | 1.4.1.3 | 43350a | 42063a | 41901a | 35676a | 43520a | 39070b | 36778b | 37143b | 29553a | 32706a | 35500a | 32690a |
| 亚硝酸还原酶 (不分解) Nitrite reductase (No-forming) | 1.4.1.4 | 13424a | 11436a | 10945a | 12922a | 12085bc | 14166a | 13367ab | 10763c | 13604a | 13240a | 14048a | 13256a |
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黄棕壤中,经化肥或生物炭处理后,与对照相比,氨合成和氨氧化作用相关酶的基因表达量有不同程度的改变,但均未达到显著差异。在潮土中,生物炭的施用（F、FC）显著降低了谷氨酸脱氢酶（2.7.2.2）,谷氨酸脱氢酶（NAD（P）+）（1.4.1.2）,谷氨酸脱氢酶（NADP+）（1.4.1.3）的表达量,另外,单施化肥也显著降低了谷氨酸脱氢酶（NADP+）（1.4.1.3）的表达量,但会显著提升亚硝酸还原酶（不分解）（1.4.1.4）的基因表达量。在黑土中经不同处理后基因表达量出现显著性变化的酶种类较少,甲酰胺酶（1.7.2.1）在炭肥同施时表达量显著提升,而氰酸裂合酶（3.5.5.1）在单施生物炭时表达量显著下降。
3 讨论
在本研究中酸性土壤施用生物炭后pH显著提高了0.6—1.0个单位,但酸性土壤的氨氧化作用不仅未发现显著提高,还出现了下降的趋势,黄棕壤氮代谢通路丰度约降低了8.4%,而潮土中奇古菌的丰度约降低了70.5%,氮代谢通路丰度也显著降低了7.8%,其中在潮土中呈现显著下降的趋势,这或许是因为本试验培养时间较短。另外,土壤pH是影响氨氧化过程相关氨氧化微生物组成及群落结构的重要因素[32],在本研究中,这3种土壤中测得β变形菌和γ变形菌数量远高于奇古菌数量,表明细菌在这三种土壤的氨氧化作用中占主导地位。很多研究都表明大多数酸性土壤中,氨氧化古菌的数量要高于氨氧化细菌,因为氨氧化古菌对低pH有更强的适应能力[33,34,35,36]。本试验采用的3种土壤分别为酸性,弱酸性以及碱性土壤,单施化肥对土壤pH的影响比生物炭弱,生物炭的添加显著提升了酸性土壤的pH,但是土壤依旧呈酸性,而黑土在施用生物炭后显著降低了pH,但土壤也仍呈碱性,在本研究中并未发现酸性土壤中奇古菌占优势。这可能与515F和806R作为测序引物有关,该引物可以用于鉴定细菌和古菌,但是更偏向于细菌鉴定[37],或许在古菌的鉴定上存在一定偏差。ABUJABHAH等[25]认为热解温度为650—750℃的桉树生物炭对土壤微生物群落和氮循环细菌的影响主要取决于土壤类型,其中对施用于红壤时作用明显高于棕壤。LIU等[26]施用了0—40 t·hm-2的稻壳生物炭（400℃）于红壤、棕壤和盐渍土中,结果发现生物炭对红壤细菌群落改变最显著。通过我们的研究也发现,花生壳生物炭对黄棕壤和潮土的细菌群落结构影响更明显,这表明生物炭对偏酸性土壤微生物群落结构存在更显著的作用,主要原因是生物炭显著提高了酸性土壤的pH,从而导致细菌群落发生显著改变。很多生物炭研究围绕不同土壤氨氧化微生物的改变得到了不同的结果。HE等[38]发现热解温度为500℃的稻壳生物炭不会对碱性土壤产生显著影响,但会改变酸性土壤的氨氧化微生物丰度。李双双等[39]在黄棕壤中施用热解温度为500℃的小麦秸秆炭发现单独施用生物炭显著降低了氨氧化细菌的丰度。也有相应研究发现在复垦土壤中施用400—500℃热解成的小麦秸秆生物炭会提高土壤氨氧化细菌和古菌的丰度,并且氨氧化细菌的丰度还会随着生物炭用量的增加而增加[40]。我们的研究结果与之不同,我们发现生物炭的施用主要降低酸性土壤中氨氧化细菌的丰度,研究结果间的差异主要与土壤类型有关。BI等[41]在砂壤土中仅施用在600℃下热解得到的稻草炭后发现并未显著影响土壤氨氧化微生物,WU等[42]也在砂壤土上进行了玉米芯生物炭的试验,结果也发现仅施用生物炭并未显著改变氨氧化微生物的组成。结合前人的研究和本试验的结果可以发现,生物炭对土壤微生物的影响,因炭而异,因土而异,在使用生物炭的时候应考虑生物炭类型和土壤类型。同时也有研究者发现长期添加生物炭和短期施用生物炭的土壤中微生物群落存在明显差异[43,44]。本研究周期相对较短,与长期试验结果是否一致有待进一步探讨。
有研究认为土壤微生物群落对化肥的投入以及土壤营养条件的改变十分敏感[45],但在不同报道中的结果差异很大且没有清晰的趋势,有研究表明肥料的施用与否对细菌群落无显著影响[46,47],但也有研究表明施肥导致了微生物群落组成的改变[48,49]。本研究中,单施化肥时并未发现黄棕壤、潮土、黑土出现显著性差异。这与GEISSELER等[50]的研究结果相似,他发现绝大部分研究中土壤主要的微生物群落并没有因为化肥的施用而产生明显的改变。同样在Ultuna 和Broadbalk 的冬小麦试验中,化肥与不施肥处理相比较,细菌的群落组成并没有显著的差异[46-47,51]。
4 结论
在土壤氨氧化作用中,黄棕壤、潮土和黑土都表现为氨氧化细菌占主导地位。生物炭的添加在短期内会对黄棕壤及潮土的细菌和古菌群落结构产生显著影响。施用生物炭后,在短期内潮土的合成氨相关酶基因表达量显著降低,氨氧化古菌丰度也明显降低,从而抑制了氨氧化作用;化肥和生物炭对黄棕壤和黑土的氨氧化作用也存在一定程度的影响。（责任编辑 李云霞）
参考文献 原文顺序
文献年度倒序
文中引用次数倒序
被引期刊影响因子
DOI:10.1126/science.1186120URLPMID:20929768 [本文引用: 1]
Atmospheric reactions and slow geological processes controlled Earth's earliest nitrogen cycle, and by ~2.7 billion years ago, a linked suite of microbial processes evolved to form the modern nitrogen cycle with robust natural feedbacks and controls. Over the past century, however, the development of new agricultural practices to satisfy a growing global demand for food has drastically disrupted the nitrogen cycle. This has led to extensive eutrophication of fresh waters and coastal zones as well as increased inventories of the potent greenhouse gas nitrous oxide (N ). Microbial processes will ultimately restore balance to the nitrogen cycle, but the damage done by humans to the nitrogen economy of the planet will persist for decades, possibly centuries, if active intervention and careful management strategies are not initiated.
URL [本文引用: 2]
本文报道了微生物在氮循环中的作用 ,论述微生物的硝化作用和反硝化作用 ,介绍了硝化作用的机理
URL [本文引用: 2]
本文报道了微生物在氮循环中的作用 ,论述微生物的硝化作用和反硝化作用 ,介绍了硝化作用的机理
DOI:10.3321/j.issn:1000-0933.2009.01.049URLMagsci [本文引用: 2]
氮的生物地球化学循环主要由微生物驱动，除固氮作用、硝化作用、反硝化作用和氨化作用外，近年还发现厌氧氨氧化是微生物参与氮循环的一个重要过程。同时，随着宏基因组学等分子生物技术的快速发展和应用，参与氮循环的新的微生物类群——氨氧化古菌也逐渐被发现。这两个重要的发现大大改变了过去人们对氮循环的认识，就近年有关厌氧氨氧化细菌、氨氧化古菌和氨氧化细菌的生态学研究进展作一简要综述。
DOI:10.3321/j.issn:1000-0933.2009.01.049URLMagsci [本文引用: 2]
氮的生物地球化学循环主要由微生物驱动，除固氮作用、硝化作用、反硝化作用和氨化作用外，近年还发现厌氧氨氧化是微生物参与氮循环的一个重要过程。同时，随着宏基因组学等分子生物技术的快速发展和应用，参与氮循环的新的微生物类群——氨氧化古菌也逐渐被发现。这两个重要的发现大大改变了过去人们对氮循环的认识，就近年有关厌氧氨氧化细菌、氨氧化古菌和氨氧化细菌的生态学研究进展作一简要综述。
DOI:10.3969/j.issn.1009-1742.2011.02.015URL [本文引用: 1]
对生物炭研究历史、现状、存在的问题及产业化前景进行了综合分析与评述,重点阐述了生物炭在能源、环境、农业等领域的应用价值与重要作用。认为生物炭在应对气候与环境变化、固碳减排、保障能源安全和粮食安全等方面都具有重要应用价值和现实意义。文章提出了以农林废弃物资源化利用为基础的生物炭研究发展方向、建议和产业化开发与应用的技术途径。为推动生物炭工程技术创新与产业化发展提供参考依据。
DOI:10.3969/j.issn.1009-1742.2011.02.015URL [本文引用: 1]
对生物炭研究历史、现状、存在的问题及产业化前景进行了综合分析与评述,重点阐述了生物炭在能源、环境、农业等领域的应用价值与重要作用。认为生物炭在应对气候与环境变化、固碳减排、保障能源安全和粮食安全等方面都具有重要应用价值和现实意义。文章提出了以农林废弃物资源化利用为基础的生物炭研究发展方向、建议和产业化开发与应用的技术途径。为推动生物炭工程技术创新与产业化发展提供参考依据。
DOI:10.5846/stxb201212281891URLMagsci [本文引用: 1]
以小麦和糜子为供试作物,利用室外盆栽试验,研究了不同添加量生物炭与矿质肥配施对两种不同土壤化学性质及小麦和糜子产量的影响。生物炭当季用量设5个水平:B0 (0 t/hm<sup>2</sup>)、B5 (5 t/hm<sup>2</sup>)、B10 (10 t/hm<sup>2</sup>)、B15 (15 t/hm<sup>2</sup>)和B20 (20 t/hm<sup>2</sup>),氮磷钾肥均作基肥施用。结果表明:1)与对照相比,施用生物炭可以显著增加新积土糜子季土壤pH值,其他处理随生物炭用量的增加虽有增加趋势但差异不显著;显著增加新积土土壤阳离子交换量,增幅为1.5%-58.2%;显著增加两种土壤有机碳含量,增幅为31.1%-272.2%;2)两种土壤的矿质态氮含量、新积土土壤有效磷和速效钾含量随生物炭用量的增加而显著提高,氮磷钾增幅分别为6.0%-112.8%、3.8%-38.5%和6.1%-47.2%;3)生物炭可显著提高塿土上作物氮吸收量,而作物磷、钾吸收量虽有增加,但差异不显著。生物炭对小麦和糜子的增产效应尚不稳定,在试验最高用量时甚至产生轻微抑制作用。总之,施用生物炭在一定程度上可以改善土壤化学性质,提高土壤有效养分含量,但生物炭对土壤和作物的影响与土壤、作物类型及土壤肥力密切相关。
DOI:10.5846/stxb201212281891URLMagsci [本文引用: 1]
以小麦和糜子为供试作物,利用室外盆栽试验,研究了不同添加量生物炭与矿质肥配施对两种不同土壤化学性质及小麦和糜子产量的影响。生物炭当季用量设5个水平:B0 (0 t/hm<sup>2</sup>)、B5 (5 t/hm<sup>2</sup>)、B10 (10 t/hm<sup>2</sup>)、B15 (15 t/hm<sup>2</sup>)和B20 (20 t/hm<sup>2</sup>),氮磷钾肥均作基肥施用。结果表明:1)与对照相比,施用生物炭可以显著增加新积土糜子季土壤pH值,其他处理随生物炭用量的增加虽有增加趋势但差异不显著;显著增加新积土土壤阳离子交换量,增幅为1.5%-58.2%;显著增加两种土壤有机碳含量,增幅为31.1%-272.2%;2)两种土壤的矿质态氮含量、新积土土壤有效磷和速效钾含量随生物炭用量的增加而显著提高,氮磷钾增幅分别为6.0%-112.8%、3.8%-38.5%和6.1%-47.2%;3)生物炭可显著提高塿土上作物氮吸收量,而作物磷、钾吸收量虽有增加,但差异不显著。生物炭对小麦和糜子的增产效应尚不稳定,在试验最高用量时甚至产生轻微抑制作用。总之,施用生物炭在一定程度上可以改善土壤化学性质,提高土壤有效养分含量,但生物炭对土壤和作物的影响与土壤、作物类型及土壤肥力密切相关。
DOI:10.11654/jaes.2015.05.013URL [本文引用: 1]
Biochar has potential to improve soil properties and enhance plant growth. A field experiment was conducted to investigate the effects of biochar additions(14 t路hm) on soil properties and alfalfa growth and nutrient uptake in desertified land in Beijing suburb. Four treatments were designed, including bare land(BL), bare land amended with biochar(BLB), alfalfa without(A) and with biochar addition(AB). Results showed that biochar additions significantly decreased soil bulk density by 11.5%~11.6%, but increased soil pH by 0.1~0.2 units, field capacity by 9.1%~10.3%, and soil total porosity by 7.6%~11.3%. Soil water content was 13.9% higher in BLB treatment than in BL treatment(<0.05). Compared to no biochar treatment, biochar additions also increased contents of total nitrogen(TN), organic carbon(OC), available nitrogen, available phosphorus, available potassium, and available zinc by 10.3%~25.8%, 52.8%~71.7%, 12.7%~23.5%, 141.7%~233.3%, 47.7%~81.1%, and 94.2%~95.2%, respectively, while decreased available iron by up to 29.1%. Cation exchange capacity(CEC), and available calcium, magnesium, manganese and boron concentrations were not significantly affected by biochar amendment. Alfalfa did not show significant impacts on soil pH, soil bulk density, total porosity, field capacity, CEC and available nitrogen, calcium magnesium, zinc, and boron, but decreased soil water content, TN concentration, available phosphorus and potassium, while increased available iron and manganese. Biochar addition enhanced dry biomass, water content, nitrogen, phosphorus, potassium, calcium, magnesium, iron, zinc, manganese, and boron contents of alfalfa shoot by 91.1%, 3.6%, 110.0%, 130.9%, 200.4%, 82.6%, 44.8%, 89.5%, 102.7%, 99.5% and 104.7%, respectively. These results suggest that a combination of biochar amendment and alfalfa planting could improve soil physicochemical properties, enhance phytoavailability of soil nutrients, and restore vegetation for desertified land in Beijing suburb.
DOI:10.11654/jaes.2015.05.013URL [本文引用: 1]
Biochar has potential to improve soil properties and enhance plant growth. A field experiment was conducted to investigate the effects of biochar additions(14 t路hm) on soil properties and alfalfa growth and nutrient uptake in desertified land in Beijing suburb. Four treatments were designed, including bare land(BL), bare land amended with biochar(BLB), alfalfa without(A) and with biochar addition(AB). Results showed that biochar additions significantly decreased soil bulk density by 11.5%~11.6%, but increased soil pH by 0.1~0.2 units, field capacity by 9.1%~10.3%, and soil total porosity by 7.6%~11.3%. Soil water content was 13.9% higher in BLB treatment than in BL treatment(<0.05). Compared to no biochar treatment, biochar additions also increased contents of total nitrogen(TN), organic carbon(OC), available nitrogen, available phosphorus, available potassium, and available zinc by 10.3%~25.8%, 52.8%~71.7%, 12.7%~23.5%, 141.7%~233.3%, 47.7%~81.1%, and 94.2%~95.2%, respectively, while decreased available iron by up to 29.1%. Cation exchange capacity(CEC), and available calcium, magnesium, manganese and boron concentrations were not significantly affected by biochar amendment. Alfalfa did not show significant impacts on soil pH, soil bulk density, total porosity, field capacity, CEC and available nitrogen, calcium magnesium, zinc, and boron, but decreased soil water content, TN concentration, available phosphorus and potassium, while increased available iron and manganese. Biochar addition enhanced dry biomass, water content, nitrogen, phosphorus, potassium, calcium, magnesium, iron, zinc, manganese, and boron contents of alfalfa shoot by 91.1%, 3.6%, 110.0%, 130.9%, 200.4%, 82.6%, 44.8%, 89.5%, 102.7%, 99.5% and 104.7%, respectively. These results suggest that a combination of biochar amendment and alfalfa planting could improve soil physicochemical properties, enhance phytoavailability of soil nutrients, and restore vegetation for desertified land in Beijing suburb.
DOI:10.11654/jaes.2014.11.017URL [本文引用: 1]
通过设置不同生物炭施用量的野外大田小区试验,研究不同处理砂壤土物理性质及水肥的变化规律。试验共设5个处理,3个重复：不施生物炭（CK）,生物炭施用量分别为10 t·hm^-2（T1）、20 t·hm^-2（T2）、40t·hm^-2（T3）、60t·hm^-2（T4）。结果表明：施用生物炭能明显减小土壤容重,增大土壤孔隙度,增加土壤含水率,与对照（CK）相比,耕作层（0～20 cm）土壤容重T4减小最大,0～10 cm减小23%,0～20cm减小30%;孔隙度T4增加最大,0～10 cm增加14%,0～20cm增加19%。施用生物炭明显提高了土壤的水分与肥料利用效率,与对照（CK）相比,处理组的水分和肥料利用效率分别最少提高27.7%和87.4%,其中T3增幅最大。生物炭能促进作物生长发育,提高作物产量,本试验番茄产量T3增幅最大,增幅为56.1%。综上所述,生物炭能改变土壤的物理性质,提高水肥利用率,减少肥料淋失,其中T3在这些指标中增幅最为明显,因此40 t·hm^-2生物炭用量是改良砂壤土最为合适的用量。
DOI:10.11654/jaes.2014.11.017URL [本文引用: 1]
通过设置不同生物炭施用量的野外大田小区试验,研究不同处理砂壤土物理性质及水肥的变化规律。试验共设5个处理,3个重复：不施生物炭（CK）,生物炭施用量分别为10 t·hm^-2（T1）、20 t·hm^-2（T2）、40t·hm^-2（T3）、60t·hm^-2（T4）。结果表明：施用生物炭能明显减小土壤容重,增大土壤孔隙度,增加土壤含水率,与对照（CK）相比,耕作层（0～20 cm）土壤容重T4减小最大,0～10 cm减小23%,0～20cm减小30%;孔隙度T4增加最大,0～10 cm增加14%,0～20cm增加19%。施用生物炭明显提高了土壤的水分与肥料利用效率,与对照（CK）相比,处理组的水分和肥料利用效率分别最少提高27.7%和87.4%,其中T3增幅最大。生物炭能促进作物生长发育,提高作物产量,本试验番茄产量T3增幅最大,增幅为56.1%。综上所述,生物炭能改变土壤的物理性质,提高水肥利用率,减少肥料淋失,其中T3在这些指标中增幅最为明显,因此40 t·hm^-2生物炭用量是改良砂壤土最为合适的用量。
URL [本文引用: 1]
【目的】分析对比黄棕壤和红壤上施用不同改良剂对白菜生长状况及土壤肥力影响的差异,为改良剂的合理利用提供依据。【方法】以生物炭（C）、腐殖酸钾（HA-K）和生石灰（CaO）为试验材料,不施改良剂为对照,分别以黄棕壤和红壤为供试土壤,通过土培盆栽试验,研究不同改良剂对白菜的生物量、养分含量、可溶性蛋白和丙二醛含量的影响,以及对不同土壤pH、养分含量、交换性铝含量和酶活性的差异。【结果】（1）与对照相比,黄棕壤和红壤上施用生物炭和生石灰均能促进白菜生长,增强其抗性,主要是提高了白菜产量、叶片氮磷钾养分含量及积累量、可溶性蛋白含量,显著降低丙二醛含量。但黄棕壤和红壤上施用腐殖酸钾对白菜生长影响不同,黄棕壤上施用腐殖酸钾使得白菜产量显著增加,达到25.93 g/株,然而红壤上施用腐殖酸钾对白菜的生长无明显改善,产量仅为0.18 g/株。（2）3种改良剂对黄棕壤和红壤的肥力效应不同,与对照相比,生物炭增加土壤pH、有效磷、速效钾、有机质含量以及脲酶与酸性磷酸酶活性,显著降低碱解氮和交换性铝含量,对土壤蔗糖酶活性无显著影响,土壤肥力得以增强,其中黄棕壤的pH增加1.39个单位,交换性铝含量减少了89.3%,有机质含量提高了168.4%;红壤的pH增加0.82个单位,交换性铝含量降低了93.9%,有机质含量提高了775.6%。对于施用腐殖酸钾和生石灰,二者均显著提高土壤pH及蔗糖酶活性,减少交换性铝含量,但腐殖酸钾对有效磷、速效钾、有机质含量以及脲酶与酸性磷酸酶活性无显著影响,显著降低碱解氮含量,交换铝含量依然很高;而施用生石灰降低土壤碱解氮、速效钾、有机质含量,对有效磷含量、脲酶与酸性磷酸酶活性无显著影响。【结论】不同改良剂对两种类型土壤上白菜生长与土壤肥力的影响有较大差异,生物炭和生17
URL [本文引用: 1]
【目的】分析对比黄棕壤和红壤上施用不同改良剂对白菜生长状况及土壤肥力影响的差异,为改良剂的合理利用提供依据。【方法】以生物炭（C）、腐殖酸钾（HA-K）和生石灰（CaO）为试验材料,不施改良剂为对照,分别以黄棕壤和红壤为供试土壤,通过土培盆栽试验,研究不同改良剂对白菜的生物量、养分含量、可溶性蛋白和丙二醛含量的影响,以及对不同土壤pH、养分含量、交换性铝含量和酶活性的差异。【结果】（1）与对照相比,黄棕壤和红壤上施用生物炭和生石灰均能促进白菜生长,增强其抗性,主要是提高了白菜产量、叶片氮磷钾养分含量及积累量、可溶性蛋白含量,显著降低丙二醛含量。但黄棕壤和红壤上施用腐殖酸钾对白菜生长影响不同,黄棕壤上施用腐殖酸钾使得白菜产量显著增加,达到25.93 g/株,然而红壤上施用腐殖酸钾对白菜的生长无明显改善,产量仅为0.18 g/株。（2）3种改良剂对黄棕壤和红壤的肥力效应不同,与对照相比,生物炭增加土壤pH、有效磷、速效钾、有机质含量以及脲酶与酸性磷酸酶活性,显著降低碱解氮和交换性铝含量,对土壤蔗糖酶活性无显著影响,土壤肥力得以增强,其中黄棕壤的pH增加1.39个单位,交换性铝含量减少了89.3%,有机质含量提高了168.4%;红壤的pH增加0.82个单位,交换性铝含量降低了93.9%,有机质含量提高了775.6%。对于施用腐殖酸钾和生石灰,二者均显著提高土壤pH及蔗糖酶活性,减少交换性铝含量,但腐殖酸钾对有效磷、速效钾、有机质含量以及脲酶与酸性磷酸酶活性无显著影响,显著降低碱解氮含量,交换铝含量依然很高;而施用生石灰降低土壤碱解氮、速效钾、有机质含量,对有效磷含量、脲酶与酸性磷酸酶活性无显著影响。【结论】不同改良剂对两种类型土壤上白菜生长与土壤肥力的影响有较大差异,生物炭和生17
DOI:10.3864/j.issn.0578-1752.2016.23.010URL [本文引用: 1]
【目的】红壤铝毒是土壤改良持续关注的问题之一。生物炭因其自身的理化和生物学特性,为探索解决该难题提供了新的思路和途径。论文通过在红壤中添加外源铝并种植作物,研究生物炭对铝富集土壤铝毒的缓解效应及潜在机制。【方法】选用酸性红壤做盆栽试验,种植小白菜,添加花生壳生物炭和外源铝,设置CK(0C+0Al)、C(2%C)、Al(1 mmol·L~(~(-1))Al)、C+Al(2%C+1 mmol·L~(~(-1))Al)4个处理,分析生物炭对铝富集红壤不同活性铝及作物生长的影响。【结果】铝毒会显著抑制小白菜的出苗,且加重红壤小白菜生长受抑制的情况,降低小白菜的生物量,同时,铝毒会显著提高小白菜铝含量。而施用生物炭能缓解铝毒对小白菜的抑制影响,显著改善小白菜的生长状况,降低小白菜铝含量,C+Al处理小白菜铝含量较Al处理降低89.4%。铝毒会显著降低红壤的pH,Al处理红壤pH较CK处理降低了0.36个单位,而施用生物炭能显著提高土壤pH,C+Al处理土壤pH较Al处理上升0.62个单位。Al处理较CK处理土壤活性铝含量上升276.4μg·g~(-1),远大于添加量(27μg·g~(-1)),而施用生物炭能显著降低土壤活性铝含量,C+Al处理较Al处理下降14.9%。此外,Al处理交换性Al~(3+)含量较CK处理上升23.1%,施用生物炭后,C+Al处理交换性Al~(3+)含量较Al处理下降46.5%。CK与Al处理土壤活性铝形态主要以具有生物毒害性的交换性Al~(3+)为主,C与C+Al处理土壤活性铝形态主要以单聚体羟基铝离子、胶体Al(OH)30为主。【结论】添加外源铝降低了土壤pH,加重铝的毒害,抑制作物的生长发育。此外,外源铝的添加对红壤中活性铝有较强的激发效应,使得交换性Al~(3+)含量显著升高。然而,生物炭能显著提高酸性土壤pH,且改变不同活性铝的含量,但其对4种不同形态活性铝的效应有较大差异,其主要通过降低具有生物毒性的Al~(3+)含量来缓解铝毒,从而改善作物生长状况。
DOI:10.3864/j.issn.0578-1752.2016.23.010URL [本文引用: 1]
【目的】红壤铝毒是土壤改良持续关注的问题之一。生物炭因其自身的理化和生物学特性,为探索解决该难题提供了新的思路和途径。论文通过在红壤中添加外源铝并种植作物,研究生物炭对铝富集土壤铝毒的缓解效应及潜在机制。【方法】选用酸性红壤做盆栽试验,种植小白菜,添加花生壳生物炭和外源铝,设置CK(0C+0Al)、C(2%C)、Al(1 mmol·L~(~(-1))Al)、C+Al(2%C+1 mmol·L~(~(-1))Al)4个处理,分析生物炭对铝富集红壤不同活性铝及作物生长的影响。【结果】铝毒会显著抑制小白菜的出苗,且加重红壤小白菜生长受抑制的情况,降低小白菜的生物量,同时,铝毒会显著提高小白菜铝含量。而施用生物炭能缓解铝毒对小白菜的抑制影响,显著改善小白菜的生长状况,降低小白菜铝含量,C+Al处理小白菜铝含量较Al处理降低89.4%。铝毒会显著降低红壤的pH,Al处理红壤pH较CK处理降低了0.36个单位,而施用生物炭能显著提高土壤pH,C+Al处理土壤pH较Al处理上升0.62个单位。Al处理较CK处理土壤活性铝含量上升276.4μg·g~(-1),远大于添加量(27μg·g~(-1)),而施用生物炭能显著降低土壤活性铝含量,C+Al处理较Al处理下降14.9%。此外,Al处理交换性Al~(3+)含量较CK处理上升23.1%,施用生物炭后,C+Al处理交换性Al~(3+)含量较Al处理下降46.5%。CK与Al处理土壤活性铝形态主要以具有生物毒害性的交换性Al~(3+)为主,C与C+Al处理土壤活性铝形态主要以单聚体羟基铝离子、胶体Al(OH)30为主。【结论】添加外源铝降低了土壤pH,加重铝的毒害,抑制作物的生长发育。此外,外源铝的添加对红壤中活性铝有较强的激发效应,使得交换性Al~(3+)含量显著升高。然而,生物炭能显著提高酸性土壤pH,且改变不同活性铝的含量,但其对4种不同形态活性铝的效应有较大差异,其主要通过降低具有生物毒性的Al~(3+)含量来缓解铝毒,从而改善作物生长状况。
DOI:10.1248/jhs.48.473URL [本文引用: 1]
DOI:10.1248/jhs.52.585URL [本文引用: 1]
DOI:10.2136/sssaj2009.0185URL [本文引用: 2]
Low-temperature pyrolysis of biomass produces a product known as biochar. The incorporation of this material into the soil has been advocated as a C sequestration method. Biochar also has the potential to influence the soil N cycle by altering nitrification rates and by adsorbing NH6262 or NH61. Biochar can be incorporated into the soil during renovation of intensively managed pasture soils. These managed pastures are a significant source of N60O, a greenhouse gas, produced in ruminant urine patches. We hypothesized that biochar effects on the N cycle could reduce the soil inorganic-N pool available for N60O-producing mechanisms. A laboratory study was performed to examine the effect of biochar incorporation into soil (20 Mg ha6301) on N60O-N and NH61–N fluxes, and inorganic-N transformations, following the application of bovine urine (760 kg N ha6301). Treatments included controls (soil only and soil plus biochar), and two urine treatments (soil plus urine and soil plus biochar plus urine). Fluxes of N60O from the biochar plus urine treatment were generally higher than from urine alone during the first 30 d, but after 50 d there was no significant difference (P = 0.11) in terms of cumulative N60O-N emitted as a percentage of the urine N applied during the 53-d period; however, NH61–N fluxes were enhanced by approximately 3% of the N applied in the biochar plus urine treatment compared with the urine-only treatment after 17 d. Soil inorganic-N pools differed between treatments, with higher NH6262 concentrations in the presence of biochar, indicative of lower rates of nitrification. The inorganic-N pool available for N60O-producing mechanisms was not reduced, however, by adding biochar.
DOI:10.1038/srep01732URLPMID:3635057 [本文引用: 1]
Agricultural soils represent the main source of anthropogenic N2O emissions. Recently, interactions of black carbon with the nitrogen cycle have been recognized and the use of biochar is being investigated as a means to reduce N2O emissions. However, the mechanisms of reduction remain unclear. Here we demonstrate the significant impact of biochar on denitrification, with a consistent decrease in N2O emissions by 10–90% in 14 different agricultural soils. Using the 15N gas-flux method we observed a consistent reduction of the N2O/(N2 + N2O) ratio, which demonstrates that biochar facilitates the last step of denitrification. Biochar acid buffer capacity was identified as an important aspect for mitigation that was not primarily caused by a pH shift in soil. We propose the function of biochar as an “electron shuttle” that facilitates the transfer of electrons to soil denitrifying microorganisms, which together with its liming effect would promote the reduction of N2O to N2.
DOI:10.1016/j.agee.2014.03.008URL [本文引用: 1]
Biochar amendment to soil has been proposed as a mechanism to mitigate climate change through an array of mechanisms; one being the mitigation of soil nitrous oxide (N2O) emissions. Yet the extent and mechanisms through which this may be achieved in temperate agroecosystems is uncertain. We used a pine chip biochar produced at a moderate temperature (550°C, PC biochar) and a walnut shell biochar produced at a higher temperature (900°C, WS biochar). Biochar was applied at 10Mgha611 to a working commercial wine grape system in North-Central California. The effects of biochar were assessed over two years at two distinct functional locations: the berm and row, which differed in N application and irrigation. N2O emissions and ancillary soil properties (NH4+, NO3, water filled pore space (WFPS), and pH) were closely monitored following management and precipitation events. Soil bulk density, cover crop yield and soil C and N were measured annually to address longer term changes in cropping system and soil properties. In the PC biochar treatment, annual cumulative N2O emissions were significantly higher than the control treatment each year (p<0.05); 4.14±1.14kg N2O-Nha611yr611 versus 2.00±0.66kg N2O-Nha611yr611 in year one, and 4.24±0.74kg N2O-Nha611yr611 versus 1.60±0.28kg N2O-Nha611yr611 in year two. Emissions of N2O in the WS biochar treatment were also higher than the control each year, but differences were not significant. The effect of biochar on N2O emissions was more pronounced in the row location where annual emissions were significantly higher than the control in one and both years for the WS and PC biochars, respectively (p<0.05). In the PC biochar treatment, we observed increased N2O emissions at both functional locations, however increases were more pronounced in the row location where they were in part attributable to increased cover crop N inputs. Differences between treatments in NH4+, NO361 and WFPS were mostly not significant. The WS biochar significantly raised soil pH relative to the control (p<0.05), however in the berm location only, and increased soil pH in this treatment did not correspond to changes in N2O emissions. Since neither biochar amendment reduced N2O emissions, our results demonstrate the need to evaluate N2O emissions at a cropping system scale (e.g. encompassing changes in N inputs and cycling) and in systems where nitrification processes may dominate emissions.
DOI:10.1128/AEM.66.12.5368-5382.2000URLPMID:92470 [本文引用: 1]
The current perception of evolutionary relationships and the natural diversity of ammonia-oxidizing bacteria (AOB) is mainly based on comparative sequence analyses of their genes encoding the 16S rRNA and the active site polypeptide of the ammonia monooxygenase (AmoA). However, only partial 16S rRNA sequences are available for many AOB species and most AOB have not yet been analyzed on the amoA...
DOI:10.1007/s12275-014-4114-0URLPMID:24972807 [本文引用: 1]
Nitrification, the oxidation of ammonia to nitrite and nitrate, has long been considered a central biological process in the global nitrogen cycle, with its first description dated 133 years ago. Until 2005, bacteria were considered the only organisms capable of nitrification. However, the recent discovery of a chemoautotrophic ammonia-oxidizing archaeon, Nitrosopumilusmaritimus, changed our concept of the range of organisms involved in nitrification, highlighting the importance of ammonia-oxidizing archaea (AOA) as potential players in global biogeochemical nitrogen transformations. The uniqueness of these archaea justified the creation of a novel archaeal phylum, Thaumarchaeota. These recent discoveries increased the global scientific interest within the microbial ecology society and have triggered an analysis of the importance of bacterial vs archaeal ammonia oxidation in a wide range of natural ecosystems. In thismini review we provide a chronological perspective of the current knowledge on the ammonia oxidation pathway of nitrification, based on the main physiological, ecological and genomic discoveries.
DOI:10.1111/j.1462-2920.2005.00906.xURLPMID:16309395 [本文引用: 1]
Mesophilic crenarchaeota are frequently found in terrestrial and marine habitats worldwide, but despite their considerable abundance the physiology of these as yet uncultivated archaea has remained unknown. From a 1.2 Gb large-insert environmental fosmid library of a calcareous grassland soil, a 43 kb genomic fragment was isolated with a ribosomal RNA that shows its affiliation to group 1.1b of crenarchaeota repeatedly found in soils. The insert encoded a homologue of a copper-containing nitrite reductase with an unusual C-terminus that encoded a potential amicyanin-like electron transfer domain as well as two proteins related to subunits of ammonia monooxygenases or particulate methane monooxygenases (AmoAB/PmoAB) respectively. Expression of nirK and the amo A-like gene was shown by reverse transcription polymerase chain reaction (PCR) analyses in soil samples, the latter being found at higher levels when the soil was incubated with ammonia (measured by quantitative PCR). Further variants of both genes were amplified from soil samples and were found in the environmental database from the Sargasso Sea plankton. Taken together, our findings suggest that mesophilic terrestrial and marine crenarchaeota might be capable of ammonia oxidation under aerobic and potentially also under anaerobic conditions.
DOI:10.1038/nrmicro1852URL [本文引用: 1]
DOI:10.1016/j.mib.2011.04.007URLPMID:21546306 [本文引用: 1]
Thaumarchaeota range among the most abundant archaea on Earth. Initially classified as ‘mesophilic Crenarchaeota’, comparative genomics has recently revealed that they form a separate and deep-branching phylum within the Archaea. This novel phylum comprises in 16S rRNA gene trees not only all known archaeal ammonia oxidizers but also several clusters of environmental sequences representing microorganisms with unknown energy metabolism. Ecophysiological studies of ammonia-oxidizing Thaumarchaeota suggest adaptation to low ammonia concentrations and an autotrophic or possibly mixotrophic lifestyle. Extrapolating from the wide substrate range of copper-containing membrane-bound monooxygenases, to which the thaumarchaeal ammonia monooxygenases belong, the use of substrates other than ammonia for generating energy by some members of the Thaumarchaeota seems likely.
DOI:10.2134/jeq2009.0138URLPMID:20830910 [本文引用: 1]
https://www.agronomy.org/publications/jeq/abstracts/39/4/1224
DOI:10.1007/s11104-007-9193-9URL [本文引用: 1]
DOI:10.1007/s00374-006-0152-zURL [本文引用: 1]
Abstract0165000201650002This study examines the potential, magnitude, and causes of enhanced biological N2 fixation (BNF) by common beans (Phaseolus vulgaris L.) through bio-char additions (charcoal, biomass-derived black carbon). Bio-char was added at 0, 30, 60, and 9001650002g kg0104000300’1 soil, and BNF was determined using the isotope dilution method after adding 15N-enriched ammonium sulfate to a Typic Haplustox cropped to a potentially nodulating bean variety (CIAT BAT 477) in comparison to its non-nodulating isoline (BAT 477NN), both inoculated with effective Rhizobium strains. The proportion of fixed N increased from 50% without bio-char additions to 72% with 9001650002g kg0104000300’1 bio-char added. While total N derived from the atmosphere (NdfA) significantly increased by 49 and 78% with 30 and 6001650002g kg0104000300’1 bio-char added to soil, respectively, NdfA decreased to 30% above the control with 9001650002g kg0104000300’1 due to low total biomass production and N uptake. The primary reason for the higher BNF with bio-char additions was the greater B and Mo availability, whereas greater K, Ca, and P availability, as well as higher pH and lower N availability and Al saturation, may have contributed to a lesser extent. Enhanced mycorrhizal infections of roots were not found to contribute to better nutrient uptake and BNF. Bean yield increased by 46% and biomass production by 39% over the control at 90 and 6001650002g kg0104000300’1 bio-char, respectively. However, biomass production and total N uptake decreased when bio-char applications were increased to 9001650002g kg0104000300’1. Soil N uptake by N-fixing beans decreased by 14, 17, and 50% when 30, 60, and 9001650002g kg0104000300’1 bio-char were added to soil, whereas the C/N ratios increased from 16 to 23.7, 28, and 35, respectively. Results demonstrate the potential of bio-char applications to improve N input into agroecosystems while pointing out the needs for long-term field studies to better understand the effects of bio-char on BNF.
DOI:10.2134/jeq2009.0082URLPMID:20830912 [本文引用: 1]
All forest fire events generate some quantity of charcoal, which may persist in soils for hundreds to thousands of years. However, few studies have effectively evaluated the potential for charcoal to influence specific microbial communities or processes. To our knowledge, no studies have specifically addressed the effect of charcoal on ammonia-oxidizing bacteria (AOB) in forest soils. Controlled...
URL [本文引用: 1]
One potential abatement strategy to increasing atmospheric levels of carbon dioxide (CO2) is to sequester atmospheric CO2 captured through photosynthesis in biomass and pyrolysed into a more stable form of carbon called biochar. We evaluated the impacts of 16 different biochars from different pyrolysis/gasification processes and feed stock materials (corn stover, peanut hulls, macadamia nut she...
DOI:10.1007/s11368-017-1733-1URL [本文引用: 2]
PurposeThe increased use of biochar as a soil amendment to alleviate the impact of agricultural practices on climate change has been a motivation for many studies to determine the effects of biochar on soil properties, particularly the abundance and activities of soil microbes and related biological processes. This study investigates the impact of different application rates of wood-derived biochar on community structure, nitrogen-cycling and methanotrophic bacteria in three soil types.Materials and methodsBiochar was added at 0, 2.5, 5 and 10% w/w to black clay loam (BCL, Vertosol), red loam (RL, Dermosol) and brown sandy loam (BSL, Kurosol) soils. Soil chemical analysis and 16S rRNA gene amplicon sequencing using the IIlumina Mi-Seq platform were conducted on initial samples and after 10-month incubation.Results and discussionThe results indicated that the addition of biochar loading levels to the different soils had a significant impact on NH4 and NO3, total C and N, pH, electrical conductivity (EC) and soil moisture content. These changes were reflected in significant differences in the bacterial diversity between biochar treatments in the BSL and RL soils, while the BCL soil was more resilient to change. Complete ammonia-oxidising (Nitrospira) and nitrite-oxidising bacteria (NOB) were more abundant than standard ammonia-oxidising bacteria (AOB) in all soils. Increased biochar loading raised the abundance of nitrifying bacteria in BCL soil while Nitrospira became more abundant in BSL soil. Biochar addition affected the abundance of certain N2 fixer groups in a soil-dependent manner. Strong positive correlations were observed in Rhizobium (r = 0.99) and Azospirillum abundance (r = 0.70) with increased biochar loading rates in BCL. Greater biochar loading also significantly increased the relative abundance of methanotrophs, especially in BCL soil.ConclusionsThe impact of biochar on community structure and nitrogen-cycling bacteria depended on soil types and biochar rates which correlated to the differences in soil properties. Overall, the abundance of nitrogen-cycling bacterial groups seemed to be most affected by the changes in soil conditions, including aeration, C/N ratio, nutrients and pH in relation to biochar application in different soils. These changes show that short-term biochar loading influences community structure and leads to increases in populations of methanotrophic and nitrifying bacteria.
DOI:10.1016/j.apsoil.2017.03.020URL [本文引用: 2]
DOI:10.1093/bioinformatics/btr507URL [本文引用: 1]
DOI:10.1038/NMETH.2604URLPMID:23955772 [本文引用: 1]
Amplified marker-gene sequences can be used to understand microbial community structure, but they suffer from a high level of sequencing and amplification artifacts. The UPARSE pipeline reports operational taxonomic unit (OTU) sequences with 09‰¤1% incorrect bases in artificial microbial community tests, compared with >3% incorrect bases commonly reported by other methods. The improved accuracy results in far fewer OTUs, consistently closer to the expected number of species in a community.
DOI:10.1128/AEM.00062-07URL [本文引用: 1]
DOI:10.1111/j.0006-341X.2002.00531.xURLPMID:12229987 [本文引用: 1]
Summary. Consider a stochastic abundance model in which the species arrive in the sample according to independent Poisson processes, where the abundance parameters of the processes follow a gamma distribution. We propose a new estimator of the number of species for this model. The estimator takes the form of the number of duplicated species (i.e., species represented by two or more individuals) divided by an estimated duplication fraction. The duplication fraction is estimated from all frequencies including singleton information. The new estimator is closely related to the sample coverage estimator presented by Chao and Lee (1992, Journal of the American Statistical Association 87, 210–217). We illustrate the procedure using the Malayan butterfly data discussed by Fisher, Corbet, and Williams (1943, Journal of Animal Ecology 12, 42–58) and a 1989 Christmas Bird Count dataset collected in Florida, U.S.A. Simulation studies show that this estimator compares well with maximum likelihood estimators (i.e., empirical Bayes estimators from the Bayesian viewpoint) for which an iterative numerical procedure is needed and may be infeasible.
DOI:10.1038/nbt.2676URLPMID:3819121 [本文引用: 1]
Profiling phylogenetic marker genes, such as the 16S rRNA gene, is a key tool for studies of microbial communities but does not provide direct evidence of a community's functional capabilities. Here we describe PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved states), a computational approach to predict the functional composition of a metagenome using marker gene data and a database of reference genomes. PICRUSt uses an extended ancestral-state reconstruction algorithm to predict which gene families are present and then combines gene families to estimate the composite metagenome. Using 16S information, PICRUSt recaptures key findings from the Human Microbiome Project and accurately predicts the abundance of gene families in host-associated and environmental communities, with quantifiable uncertainty. Our results demonstrate that phylogeny and function are sufficiently linked that this 'predictive metagenomic' approach should provide useful insights into the thousands of uncultivated microbial communities for which only marker gene surveys are currently available.
[D].
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[D].
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DOI:10.1038/nature04983URLPMID:16915287 [本文引用: 1]
Ammonia oxidation is the first step in nitrification, a key process in the global nitrogen cycle that results in the formation of nitrate through microbial activity. The increase in nitrate availability in soils is important for plant nutrition, but it also has considerable impact on groundwater pollution owing to leaching. Here we show that archaeal ammonia oxidizers are more abundant in soils than their well-known bacterial counterparts. We investigated the abundance of the gene encoding a subunit of the key enzyme ammonia monooxygenase (amoA) in 12 pristine and agricultural soils of three climatic zones. amoA gene copies of Crenarchaeota (Archaea) were up to 3,000-fold more abundant than bacterial amoA genes. High amounts of crenarchaeota-specific lipids, including crenarchaeol, correlated with the abundance of archaeal amoA gene copies. Furthermore, reverse transcription quantitative PCR studies and complementary DNA analysis using novel cloning-independent pyrosequencing technology demonstrated the activity of the archaea in situ and supported the numerical dominance of archaeal over bacterial ammonia oxidizers. Our results indicate that crenarchaeota may be the most abundant ammonia-oxidizing organisms in soil ecosystems on Earth.
DOI:10.1111/j.1462-2920.2008.01701.xURLPMID:18707610 [本文引用: 1]
Autotrophic ammonia oxidation occurs in acid soils, even though laboratory cultures of isolated ammonia oxidizing bacteria fail to grow below neutral pH. To investigate whether archaea possessing ammonia monooxygenase genes were responsible for autotrophic nitrification in acid soils, the community structure and phylogeny of ammonia oxidizing bacteria and archaea were determined across a soil pH gradient (4.9 7.5) by amplifying 16S rRNA and amoA genes followed by denaturing gradient gel electrophoresis (DGGE) and sequence analysis. The structure of both communities changed with soil pH, with distinct populations in acid and neutral soils. Phylogenetic reconstructions of crenarchaeal 16S rRNA and amo A genes confirmed selection of distinct lineages within the pH gradient and high similarity in phylogenies indicated a high level of congruence between 16S rRNA and amoA genes. The abundance of archaeal and bacterial amoA gene copies and mRNA transcripts contrasted across the pH gradient. Archaeal amoA gene and transcript abundance decreased with increasing soil pH, while bacterial amoA gene abundance was generally lower and transcripts increased with increasing pH. Short-term activity was investigated by DGGE analysis of gene transcripts in microcosms containing acidic or neutral soil or mixed soil with pH readjusted to that of native soils. Although mixed soil microcosms contained identical archaeal ammonia oxidizer communities, those adapted to acidic or neutral pH ranges showed greater relative activity at their native soil pH. Findings indicate that different bacterial and archaeal ammonia oxidizer phylotypes are selected in soils of different pH and that these differences in community structure and abundances are reflected in different contributions to ammonia oxidizer activity. They also suggest that both groups of ammonia oxidizers have distinct physiological characteristics and ecological niches, with consequences for nitrification in acid soils.
DOI:10.1128/AEM.00595-10URLPMID:20889787 [本文引用: 1]
Abstract Both bacteria and thaumarchaea contribute to ammonia oxidation, the first step in nitrification. The abundance of putative ammonia oxidizers is estimated by quantification of the functional gene amoA, which encodes ammonia monooxygenase subunit A. In soil, thaumarchaeal amoA genes often outnumber the equivalent bacterial genes. Ecophysiological studies indicate that thaumarchaeal ammonia oxidizers may have a selective advantage at low ammonia concentrations, with potential adaptation to soils in which mineralization is the major source of ammonia. To test this hypothesis, thaumarchaeal and bacterial ammonia oxidizers were investigated during nitrification in microcosms containing an organic, acidic forest peat soil (pH 4.1) with a low ammonium concentration but high potential for ammonia release during mineralization. Net nitrification rates were high but were not influenced by addition of ammonium. Bacterial amoA genes could not be detected, presumably because of low abundance of bacterial ammonia oxidizers. Phylogenetic analysis of thaumarchaeal 16S rRNA gene sequences indicated that dominant populations belonged to group 1.1c, 1.3, and "deep peat" lineages, while known amo-containing lineages (groups 1.1a and 1.1b) comprised only a small proportion of the total community. Growth of thaumarchaeal ammonia oxidizers was indicated by increased abundance of amoA genes during nitrification but was unaffected by addition of ammonium. Similarly, denaturing gradient gel electrophoresis analysis of amoA gene transcripts demonstrated small temporal changes in thaumarchaeal ammonia oxidizer communities but no effect of ammonium amendment. Thaumarchaea therefore appeared to dominate ammonia oxidation in this soil and oxidized ammonia arising from mineralization of organic matter rather than added inorganic nitrogen.
DOI:10.1007/s11356-014-3393-7URLPMID:25087501 [本文引用: 1]
Biofiltration has been widely used to reduce organic matter and control the formation of disinfection by-products in drinking water. Backwashing might affect the biofilters performance and the attached microbiota on filter medium. In this study, the impacts of backwashing on the removal of dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and N -nitrosamine precursors by a pilot-scale biological activated carbon (BAC) filtration system were investigated. The impacts of backwashing on biomass and microbial community structure of BAC biofilm were also investigated. Phospholipid fatty acid (PLFA) analysis showed that backwashing reduced nearly half of the attached biomass on granular activated carbon (GAC) particles, followed by a recovery to the pre-backwashing biomass concentration in 2 days after backwashing. Backwashing was found to transitionally improve the removal of DOC, DON and N -nitrosamine precursors. MiSeq sequencing analysis revealed that backwashing had a strong impact on the bacterial diversity and community structure of BAC biofilm, but they could gradually recover with the operating time after backwashing. Phylum Proteobacteria was the largest bacterial group in BAC biofilm. Microorganisms from genera Bradyrhizobium , Hyphomicrobium , Microcystis and Sphingobium might contribute to the effective removal of nitrogenous organic compounds by drinking water biofilter. This work could add some new insights towards the operation of drinking water biofilters and the biological removal of organic matter.
DOI:10.1016/j.scitotenv.2017.11.029URLPMID:29734589 [本文引用: 1]
Black soils (Mollisols) of northeast China are highly productive and agriculturally important for food production. Ammonia-oxidizing microbes play an important role in N cycling in the black soils. However, the information related to the composition and distribution of ammonia-oxidizing microbes in the black soils has not yet been addressed. In this study, we used the amoA gene to quantify the... [Show full abstract]
DOI:10.11674/zwyf.17272URL [本文引用: 1]
[目的]生物质炭显著影响土壤氧化亚氮(N2O)排放,但关于其相关微生物机理的研究相对匮乏,尤其是生物质炭对酸性菜地土壤N2O排放的微生物作用机理.本文通过研究氮肥配施生物质炭对酸性菜地土壤N2O排放以及硝化和反硝化过程相关功能基因丰度的影响,探讨酸性菜地土壤N2O排放与功能基因丰度的关系,阐释生物质炭对酸性菜地土壤试验N2O排放的微生物作用机理.[方法]在田间一次性施入生物质炭40 t/hm2,试验连续进行了3年,共9茬蔬菜.设置4个处理:对照(CK)、氮肥(N)、生物质炭(Bc)和氮肥+生物质炭(N+Bc).在施用后第三年,采集土壤样品进行室内培养,应用荧光定量PCR技术检测硝化过程氨氧化古菌(AOA)、氨氧化细菌(AOB)功能基因amoA和反硝化过程亚硝酸还原酶基因(nirK、nirS)以及N2O还原酶基因(nosZ)等相关功能基因丰度,同时监测土壤pH值、无机氮(铵态氮、硝态氮)含量及N2O排放.[结果]与CK相比,生物质炭(Bc)处理的土壤有机碳(SOC)提高了27.1％,总氮(TN)提高了8.2％,amoA-AOB基因丰度显著降低了11.0％,nosZ基因丰度增加了21.2％ (P＜ 0.05),N2O排放没有显著变化(P＞0.05).与CK相比,施用氮肥(N)显著降低土壤pH(P＜0.05),显著增加土壤无机氮含量、nirK、nirS和nosZ功能基因丰度以及土壤N2O累积排放量(P＜0.05).与N处理相比,生物质炭与氮肥联合施用(N+Bc)处理显著增加amoA-AOA、amoA-AOB、nirK、nirS和nosZ基因丰度,增幅分别为68.1％、39.3％、21.1％、19.8％、48.4％ (P＜ 0.05),但(nirK+nirS)/nosZ的比值降低,同时N2O累积排放量显著降低33.3％ (P＜ 0.05).室内培养期间N2O排放峰出现在1～5d,N和N+Bc处理排放速率分别为N 1.70×103和1.76×103 ng/(kg·h).相关分析结果显示,N2O排放速率与氧化亚氮还原酶的标记基因nosZ基因拷贝数(P＜0.05)、NH4+-N含量(P＜0.01)呈显著正相关,与pH呈显著负相关(P＜0.01).[结论]在菜地生态系统中氮肥和生物质炭联合施用可以有效缓解菜地土壤酸化,减少菜地土壤N2O排放,主要归因于反硝化作用nosZ基因丰度增加,(nirK+ nirS)/nosZ比值降低.
DOI:10.11674/zwyf.17272URL [本文引用: 1]
[目的]生物质炭显著影响土壤氧化亚氮(N2O)排放,但关于其相关微生物机理的研究相对匮乏,尤其是生物质炭对酸性菜地土壤N2O排放的微生物作用机理.本文通过研究氮肥配施生物质炭对酸性菜地土壤N2O排放以及硝化和反硝化过程相关功能基因丰度的影响,探讨酸性菜地土壤N2O排放与功能基因丰度的关系,阐释生物质炭对酸性菜地土壤试验N2O排放的微生物作用机理.[方法]在田间一次性施入生物质炭40 t/hm2,试验连续进行了3年,共9茬蔬菜.设置4个处理:对照(CK)、氮肥(N)、生物质炭(Bc)和氮肥+生物质炭(N+Bc).在施用后第三年,采集土壤样品进行室内培养,应用荧光定量PCR技术检测硝化过程氨氧化古菌(AOA)、氨氧化细菌(AOB)功能基因amoA和反硝化过程亚硝酸还原酶基因(nirK、nirS)以及N2O还原酶基因(nosZ)等相关功能基因丰度,同时监测土壤pH值、无机氮(铵态氮、硝态氮)含量及N2O排放.[结果]与CK相比,生物质炭(Bc)处理的土壤有机碳(SOC)提高了27.1％,总氮(TN)提高了8.2％,amoA-AOB基因丰度显著降低了11.0％,nosZ基因丰度增加了21.2％ (P＜ 0.05),N2O排放没有显著变化(P＞0.05).与CK相比,施用氮肥(N)显著降低土壤pH(P＜0.05),显著增加土壤无机氮含量、nirK、nirS和nosZ功能基因丰度以及土壤N2O累积排放量(P＜0.05).与N处理相比,生物质炭与氮肥联合施用(N+Bc)处理显著增加amoA-AOA、amoA-AOB、nirK、nirS和nosZ基因丰度,增幅分别为68.1％、39.3％、21.1％、19.8％、48.4％ (P＜ 0.05),但(nirK+nirS)/nosZ的比值降低,同时N2O累积排放量显著降低33.3％ (P＜ 0.05).室内培养期间N2O排放峰出现在1～5d,N和N+Bc处理排放速率分别为N 1.70×103和1.76×103 ng/(kg·h).相关分析结果显示,N2O排放速率与氧化亚氮还原酶的标记基因nosZ基因拷贝数(P＜0.05)、NH4+-N含量(P＜0.01)呈显著正相关,与pH呈显著负相关(P＜0.01).[结论]在菜地生态系统中氮肥和生物质炭联合施用可以有效缓解菜地土壤酸化,减少菜地土壤N2O排放,主要归因于反硝化作用nosZ基因丰度增加,(nirK+ nirS)/nosZ比值降低.
DOI:10.13287/j.1001-9332.201710.034URL [本文引用: 1]
生物质炭作为一种新型土壤改良剂,施入土壤不仅能提高肥力,改善土壤结构,还能够影响土壤氮素的转化.本文利用培养试验研究施用生物质炭对采煤塌陷区土壤性质及氨氧化菌丰度和群落结构的影响.结果表明:生物质炭显著提高土壤铵氮(NH4+-N)、全氮、有效磷和速效钾含量.生物质炭施用量对氨氧化古菌(AOA)丰度没有显著影响,但是增加施用量显著提高了氨氧化细菌(AOB)丰度.对T-RFLP数据进行分析发现,生物质炭提高了AOA和AOB多样性,并在一定程度上改变了AOA和AOB群落结构.施用生物质炭提高了采煤塌陷区土壤养分含量,并在一定程度上提高了氨氧化菌的丰度和多样性,表明生物质炭对塌陷区复垦土壤具有培肥改良的潜能.
DOI:10.13287/j.1001-9332.201710.034URL [本文引用: 1]
生物质炭作为一种新型土壤改良剂,施入土壤不仅能提高肥力,改善土壤结构,还能够影响土壤氮素的转化.本文利用培养试验研究施用生物质炭对采煤塌陷区土壤性质及氨氧化菌丰度和群落结构的影响.结果表明:生物质炭显著提高土壤铵氮(NH4+-N)、全氮、有效磷和速效钾含量.生物质炭施用量对氨氧化古菌(AOA)丰度没有显著影响,但是增加施用量显著提高了氨氧化细菌(AOB)丰度.对T-RFLP数据进行分析发现,生物质炭提高了AOA和AOB多样性,并在一定程度上改变了AOA和AOB群落结构.施用生物质炭提高了采煤塌陷区土壤养分含量,并在一定程度上提高了氨氧化菌的丰度和多样性,表明生物质炭对塌陷区复垦土壤具有培肥改良的潜能.
DOI:10.1186/s13568-017-0363-8URLPMID:28571306 [本文引用: 1]
Biosurfactants are unique secondary metabolites, synthesised non-ribosomally by certain bacteria, fungi and yeast, with their most promising applications as antimicrobial agents and surfactants in the medical and food industries. Naturally produced glycolipids and lipopeptides are found as a mixture of congeners, which increases their antimicrobial potency. Sensitive analysis techniques, such as liquid chromatography coupled to mass spectrometry, enable the fingerprinting of different biosurfactant congeners within a naturally produced crude extract.Bacillus amyloliquefaciensST34 andPseudomonas aeruginosaST5, isolated from wastewater, were screened for biosurfactant production. Biosurfactant compounds were solvent extracted and characterised using ultra-performance liquid chromatography (UPLC) coupled to electrospray ionisation mass spectrometry (ESI–MS). Results indicated thatB.amyloliquefaciensST34 produced C13–16surfactin analogues and their identity were confirmed by high resolution ESI–MS and UPLC–MS. In the crude extract obtained fromP. aeruginosaST5, high resolution ESI–MS linked to UPLC–MS confirmed the presence of di- and monorhamnolipid congeners, specifically Rha–Rha–C10–C10and Rha–C10–C10, Rha–Rha–C8–C10/Rha–Rha–C10–C8and Rha–C8–C10/Rha–C10–C8, as well as Rha–Rha–C12–C10/Rha–Rha–C10–C12and Rha–C12–C10/Rha–C10–C12. The crude surfactin and rhamnolipid extracts also retained pronounced antimicrobial activity against a broad spectrum of opportunistic and pathogenic microorganisms, including antibiotic resistantStaphylococcus aureusandEscherichia colistrains and the pathogenic yeastCandida albicans. In addition, the rapid solvent extraction combined with UPLC–MS of the crude samples is a simple and powerful technique to provide fast, sensitive and highly specific data on the characterisation of biosurfactant compounds. The online version of this article (doi:10.1186/s13568-017-0363-8) contains supplementary material, which is available to authorized users.
DOI:10.1007/s00253-016-7614-5PMID:27338575 [本文引用: 1]
Abstract Biochar and compost are seen as two attractive waste management options and are used for soil amendment and pollution remediation. The interaction between biochar and composting may improve the potential benefits of biochar and compost. We investigated soil physicochemical properties, bacterial community, bacterial 16S rRNA, and functional marker genes of nitrogen cycling of the soil remedied with nothing (S), compost (SC), biochar (SB), a mixture of compost and biochar (SBC), composted biochar (SBced), and a composted mixture of biochar and biomass (SBCing). The results were that all amendments (1) increased the bacterial community richness (except SB) and SBCing showed the greatest efficiency; (2) increased the bacterial community diversity (SBCing > SBC > SC > SBced > SB > S); and (3) changed the gene copy numbers of 16S rRNA, nirK, nirS, and nosZ genes of bacteria, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB). All amendments (except SB) could increase the gene copy number of 16S rRNA, and SBCing had the greatest efficiency. The changes of soil bacterial community richness and diversity and the gene copy numbers of 16S rRNA, nirK, nirS, nosZ, AOA, and AOB would affect carbon and nitrogen cycling of the ecosystem and also implied that BCing had the greatest efficiency on soil amendment.
[D].
[本文引用: 1]
DOI:10.1016/j.soilbio.2010.11.005URL [本文引用: 1]
The effects of pyrogenic carbon on the microbial diversity of forest soils were examined by comparing two soil types, fire-impacted and non-impacted, that were incubated with laboratory-generated biochars. Molecular and culture-dependent analyses of the biochar-treated forest soils revealed shifts in the relative abundance and diversity of key taxa upon the addition of biochars, which were dependent on biochar and soil type. Specifically, there was an overall loss of microbial diversity in all soils treated with oak and grass-derived biochar as detected by automated ribosomal intergenic spacer analysis. Although the overall diversity decreased upon biochar amendments, there were increases in specific taxa during biochar-amended incubation. DNA sequencing of these taxa revealed an increase in the relative abundance of bacteria within the phyla Actinobacteria and Gemmatimonadetes in biochar-treated soils. Together, these results reveal a pronounced impact of pyrogenic carbon on soil microbial community composition and an enrichment of key taxa within the parent soil microbial community.
DOI:10.1073/pnas.0801925105URL [本文引用: 1]
DOI:10.1007/s00374-011-0623-8 [本文引用: 2]
The Ultuna long-term soil organic matter experiment in Sweden (59′82° N, 17′65° E) was started in 1956 to study the effects of different N fertilisers and organic amendments on soil properties. In...
DOI:10.1038/ismej.2008.128URLPMID:19148144 [本文引用: 2]
The relative importance of size and composition of microbial communities in ecosystem functioning is poorly understood. Here, we investigated how community composition and size of selected functional guilds in the nitrogen cycle correlated with agroecosystem functioning, which was defined as microbial process rates, total crop yield and nitrogen content in the crop. Soil was sampled from a 50-y...
DOI:10.1111/j.1574-6941.2006.00132.xURLPMID:16907752 [本文引用: 1]
Biological soil characteristics such as microbial biomass, community structures, activities, and functions may provide important information on environmental and anthropogenic influences on agricultural soils. Diagnostic tools and detailed statistical approaches need to be developed for a reliable evaluation of these parameters, in order to allow classification and quantification of the magnitude of such effects. The DOK long-term agricultural field experiment was initiated in 1978 in Switzerland for the evaluation of organic and conventional farming practices. It includes three representative Swiss farming systems with biodynamic, bio-organic and conventional fertilization and plant protection schemes along with minerally fertilized and unfertilized controls. Effects on microbial soil characteristics induced by the long-term management at two different stages in the crop rotation, i.e. winter wheat after potato or corn, were investigated by analyzing soil bacterial community structures using analysis of PCR-amplified rRNA genes by terminal restriction fragment length polymorphism and ribosomal intergenic spacer analysis. Application of farmyard manure consistently revealed the strongest influence on bacterial community structures and biomass contents. Effects of management and plant protection regimes occurred on an intermediate level, while the two stages in the crop rotation had a marginal influence that was not significant.
DOI:10.1007/s11104-009-9988-yURL [本文引用: 1]
DOI:10.1016/j.apsoil.2016.04.015URL [本文引用: 1]
Anthropogenic inputs of reactive nitrogen (N) to terrestrial ecosystems have increased considerably over the past several decades. Soil microorganisms provide numerous ecosystem services and are closely linked to the global carbon cycle through decomposition of organic material. The objectives of this study were to quantify the long- and short-term effects of mineral N input (ammonium, nitrate or urea) on soil microorganisms in permanent grassland and annual cropping systems. Conducting ameta-analysis, we found that in grassland studies (n=54), soil microbial biomass (SMB) decreased significantly by 12% with N addition, while SMB increased significantly by 13.6% in annual crops (n=150). Pronounced shifts among major microbial groups from N additions were not evident in our analysis, even though individual studies sometimes found significant effects of N input on PLFA profiles. We found the best support for the hypothesis that higher crop productivity in annual cropping systems brought on by fertilization increases plant residue inputs, which in turn increases SMB in the long term. In the short term, N inputs may also increase primary production in permanent grassland. However, N inputs gradually reduce grassland plant species richness which likely leads to the observed decrease in SMB. Over time, the effect of plant species richness on SMB becomes more pronounced. Our analysis reveals that management is an important consideration in predicting how ecosystems respond to environmental change and highlights the complexity and diversity of plant-microbial interactions, and underscores the immense value of long-term field trials.
DOI:10.1007/s00248-008-9372-0URLPMID:18347845 [本文引用: 1]
With more than 160 years of contrasting fertilizer regimes, the Broadbalk winter wheat experiment represents a unique experimental resource for studying the effects of long-term fertilizer application on microbial population diversity. Using DGGE and clone library analysis, we report here on eubacterial species diversity (16S rRNA gene) and diversity within two sets of gene products associated with microbial acquisition: NifH (nitrogen fixation) and AmtB (ammonium transport). Comparisons were made within and between soils treated with mineral fertilizer, farmyard manure or receiving no fertilizer. Analysis of 16S rRNA gene DGGE profiles showed no clear patterns to qualitatively distinguish bacterial community structure between the three different treatments (P>0.05), with all samples containing a range of eubacterial taxa similar to those that are characteristic of soil bacteria reported elsewhere. Intra-plot heterogeneity was high and of a similar magnitude to that between treatments. This lack of qualitative between plot differences was echoed in the representative sequences of 16S rRNA, nifH, and amtB genes in the various samples. Taken together, both phylogenetic and functional gene analyses showed bacterial communities in the Broadbalk-trial soil were very stable and relatively non-responsive to long-term management of balanced fertilizer inputs.
