长期轮作施肥对棕壤腐殖酸动态变化的影响

在沈阳地区棕壤上设置长期定位试验。结果表明,凡经１５年在玉米—大豆—玉米轮作条件下连续施用猪厩肥和ＮＰＫ化肥,耕层土壤胡敏酸Ｃ相对下降５４５％,富里酸Ｃ相对提高１６２６％,ＨＡ／ＦＡ比由１９７９年的２６９降到１９９３年的０４６,土壤腐殖质组成以胡敏酸为主体转化为以富里酸为主体。本文还讨论了不同施肥处理对腐殖酸消长的影响。     

长期施用不同肥料对红壤稻田产量和土壤有机质品质的影响

定位试验的结果表明 ,施肥能显著提高作物产量 ,产量水平和稳定性以NPKM为最好 .仅施NPK土壤有机质、胡敏酸提高甚少 ,有提高KOS和降低HA/FA的趋势 ;稻草还田和增施猪厩肥 ,有机质含量明显提高 ,Kos下降 ,HA/FA提高 ,有机质品质得以改善     

Effect of Fe,Mn or Al Compounds on Humification of Three Types of Plant Residues during Thermal Incubation

The effect of three inorganic minerals on the humification of three types of plant residues was determined by employing a model thermal incubation experiment. The plant residues consisiting of rice (Oryza sativa) straw, broadleaf tree (a mixture of oak/beech, Quercus serrata, Q. dentata, Q. acutissima etc.) sawdust and Japanese cedar (Cryptomeria japonica) sawdust were each mixed with Fe, Mn and Al in the form of hydroxides, oxides and sulfates. Humic materials were extracted after incubation and their composition was analyzed using a mixed solution of 0.02 M Na₄P₂O₇ and 0.1 M NaOH. The pH values of the samples after a longer duration of the incubation period were all less than 5.0, with the lowest value of 2.16 for a sample incubated with Al₂(SO₄)₃, except for the values of the samples incubated with MnO₂, which ranged from 4.75 to 6.0. The ΔlogK values decreased with the increase of the duration of the incubation period, whereas the RF values increased, as well as the amount of humus extracted (HE) and percentage of humic acid (PQ). Whereas most of the samples were identified as Type B and Type Rp humic acids, Type A humic acid was formed in all the plant residues incubated with Al₂(SO₄)₃, FeO(OH) and MnO₂ after ?180 d of incubation period. Moreover, the degree of humification of the plant residues was observed in the order of broadleaf tree > rice straw > Japanese cedar. It can be concluded that the inorganic compounds Al₂(SO₄)₃, FeO(OH) and MnO₂ contributed to the acceleration of the humification process of plant residues during the thermal incubation. The effect of Al₂(SO₄)₃ may be associated with the increase in the reactivity with other components in the system due to its high solubility, whereas FeO(OH) and MnO₂ may be involved in a reduction-oxidation reaction during the incubation. The browning and/or blackening of the plant residues were similar to the production of melanoidin which led us to consider that the mechanism involved in the study was similar to that of the Maillard reaction.     

FTIR‐spectroscopic characterization of humic acids and humin fractions obtained by advanced NaOH,Na4P2O7, and Na2CO3 extraction procedures

Aim of our study was the development of the methodological basis for the characterization of humic fractions of a long‐term field experiment. Humic acids (HAs) were extracted from three layers of a nontilled soil using three different extractants (1 M NaOH, 0.1 M Na₄P₂O₇, 1 M Na₂CO₃), and the humin fraction was enriched. NaOH as extractant for FTIR analysis of humic substances yields higher resolved IR spectra, especially in the important regions of stretching vibrations including aromatic and aliphatic groups and in the fingerprint area including amides, aliphats, and aromats than the other extractants. The NaOH extraction has lower extraction yields as compared to Na₄P₂O₇ and Na₂CO₃ and represents a different part of the soil organic matter (SOM). This is reflected by lower C : N ratios and higher E₄ : E₆ and fulvic acid–to–humic acid ratios as compared to the other extractants. The FTIR band areas of HA fraction obtained by NaOH showed an increase of the aromatic and carbonyl groups and a decrease of amide groups with increasing soil depth. Aliphatic groups showed contradicting results: The bands of the stretching vibrations increased, and the band of the bending vibrations decreased. We assume that band interactions in the bending vibrations were responsible for that phenomenon under the assumption of an increase of aliphatic groups with increasing soil depth. The IR bands of the enriched humin fraction showed a decreasing trend in case of both aliphatic bands deriving from stretching vibrations and an increase of aromatic characteristics with depth. Our study led to the conclusion that HA fractions obtained by 1 M NaOH represent a small and dynamic fraction indicated by the measured yields in combination with values of N_t, C : N, E₄ : E₆ ratios, and ratios of fulvic acids (FA) to HA. The humin fraction has a high contribution to the total organic C and represents a more stabilized fraction of SOM which still shows changes in its aromatic and aliphatic characteristics with soil depth.     

腐殖物质对有机污染物的吸附行为及环境学意义

综述了近年来腐殖物质的研究进展,具体包含以下几个方面的内容:腐殖物质的分离、纯化、元素组成和结构特征及其环境意义。重点讨论了腐殖物质的环境学意义,阐述了腐殖物质主要是胡敏素在吸附疏水性有机污染物的过程中所起到的重要作用,其中包括可溶性腐殖物质的增溶作用和不溶性腐殖物质———胡敏素的吸附固定作用;且对吸附/解吸的机理及一些模型的建立进行了探讨。最后针对研究中面临的问题,提出了今后的重点研究方向。     

腐殖酸复合肥对葡萄养分吸收及产量的影响

针对长期大量施用化肥使果园土壤养分失衡、果品质量下降等问题，研究了新型腐殖酸复合肥用以大田葡萄的应用效果。结果表明，所有施肥处理比对照有显著的增产效果。在投入养分量相等条件下，腐殖酸能显著提高叶片中氮、磷、钾的浓度，促进葡萄叶片中叶绿素的合成代谢和果实对养分的吸收，增加葡萄产量。     

不同组分的腐植酸复合肥在辣椒上的施用效应及其生理机制研究

采用盆栽试验方法,研究了不同组分的腐植酸复合肥对辣椒生长及其生理特性的影响,以筛选出适于辣椒生长的最佳肥料方案。试验结果表明,不同组分腐植酸复合肥处理与等养分无机复合肥及对照相比,产量均有显著提高,提高幅度分别为8.1％～23.5％和165.0％～195.1％。其中以HAzn增产效果最为显著。对辣椒生理活性的影响,也是以HAZn总体表现效果最佳,它可提高辣椒体内NR、SOD、POD的活性,促进叶绿素的合成代谢。此外,微量元素锌、铁之间存在着一定的拮抗作用,在一个施肥方案中,二者不宜同时施用。     

流感病毒血凝素茎干部通用疫苗的构建及免疫原性研究

为了构建基于血凝素(hemagglutinin,HA)茎干部的流感通用疫苗并研究其免疫原性,本研究以A/Puerto Rico/8/1934(H 1Nl)流感病毒为模板,扩增HA茎干部区域主要蛋白HA2(HA的344～566 aa)和完整茎干部HA-stem(缺失53 aa～276 aa的HA),与真核表达载体pCAGGS连接获得重组质粒.将重组质粒瞬时转染至HEK-293T细胞,利用RT-PCR及间接免疫荧光实验检测其表达情况.将6～8周龄健康雌性BALB/c小鼠(Mus musculus)分为4组,即2个重组质粒组及pCAGGS质粒对照组和磷酸盐缓冲液(phosphate buffer saline,PBS)对照组,分别于0和30 d免疫2次,在免疫当天(第0天)及免疫后第60天采集小鼠眼眶血,测定其HI抗体、细胞中和抗体和IFN-γ水平.结果表明,成功构建了重组质粒pCAGGS-HA2和pCAGGS-HA-stem,且重组质粒转染HEK-293T细胞后均能检测到目的蛋白及其mRNA.免疫后第60天pCAGGS-HA2和pCAGGS-HA-stem免疫组对A/Puerto Rico/8/1934(H1N1)病毒的HI抗体效价均为5 log2,中和抗体效价分别为1∶27和1∶24.对异源病毒A/Chicken/Hebei/4/2008(H9N2)病毒的HI抗体效价分别为3 log2和6 log2,中和抗体效价分别为1∶24和1∶22.pCAGGS-HA2和pCAGGS-HA-stem组1NF-γ含量分别为(2362.40+98.24) ng/L和(2497.06+ 120.44) ng/L.pCAGGS-HA2及pCAGGS-HA-stem诱导产生的抗体及INF-γ水平与免疫前及对照组相比差异显著(P＜0.05).结果表明,pCAGGS-HA2和pCAGGS-HA-stem能够诱导对异源病毒的交叉反应,有望作为候选的流感通用疫苗.     

高黎贡山土壤腐殖质特性与团聚体数量特征研究

采用野外调查与室内分析结合的方法,研究高黎贡山土壤腐殖质特性与团聚体数量特征,对进一步了解高黎贡山生态系统中土壤特征,降低土壤侵蚀,减少水土流失提供科学依据。结果表明:土壤腐殖质的组成具有明显地带性特征,有机质、腐殖酸含量、胡/富(HA/FA)随海拔高度的降低呈先上升后下降的趋势,A1层胡敏酸(HA)、富里酸(FA)含量分布规律为暗棕壤棕壤棕色针叶林土亚高山草甸土黄棕壤黄壤黄红壤。A2层腐殖酸、FA变化趋势为暗棕壤棕壤棕色针叶林土黄棕壤黄壤亚高山草甸土黄红壤。A1层HA、FA分子复杂程度、化学稳定性比A2层强。1～0.5mm和0.25mm粒径的团聚体含量占绝大多数,约占60%～70%。随着海拔高度的降低,粗粒减少,细粒增多。土壤团聚体服从对数正态分布,其几何平均直径与几何标准差、土壤可蚀性K值之间存在负相关关系,土壤可蚀性K值与几何标准差存在正相关关系,同时土壤也具有一定的分形特性。其中亚高山草甸土几何平均直径(Dg)、平均重量直径(MWD)值最大,几何标准差(δg)、可蚀性K值、分形维数(CFD)值最小,土壤结构稳定性和抗蚀能力相对较强。胡敏酸含量是影响土壤可蚀性的重要因素。     

不同利用方式下黄泥土中胡敏酸对芘的吸附特性初探

采用高效液相色谱法测定三种不同利用方式下黄泥土中胡敏酸对芘的吸附效应。结果表明:桑园、水田、水杉土壤中胡敏酸对芘的吸附在低浓度范围近似线性,而浓度较高时,吸附曲线的非线性增强,三者呈现相似的非线性吸附。但是,十年时间的不同利用方式对土壤中胡敏酸元素组成影响较小,桑园、水田、水杉土壤中胡敏酸对芘的吸附分配系数有一定差别,说明不同胡敏酸对芘的吸附能力不同,必然与其组成结构有关。不同利用方式下黄泥土中胡敏酸对芘的吸附等温线用Freundlich等温方程拟合效果很好,均达到显著相关。     

灌溉方式对设施土壤总有机碳及其腐殖质组分的影响

通过13年连续的番茄栽培灌溉试验,分析了沟灌、滴灌和渗灌3种灌溉处理0—80cm土层土壤有机碳及其腐殖质组分(胡敏酸、富里酸、胡敏素等)含量,探讨了不同灌溉方法对温室土壤有机质变化的影响。结果表明:3种灌溉处理土壤总有机碳、腐殖质各组分含量剖面变化特征一致,均随土层加深而降低,且这一变化主要集中在0—50cm土层,50—80cm土层变化较小。土壤总有机碳及其组分各灌溉处理间差异明显,将土壤剖面分为0—20,20—80cm上、下2个层次,总体上总有机碳含量上层为渗灌沟灌滴灌,下层滴灌沟灌渗灌;腐殖酸含量上层滴灌沟灌渗灌,下层为渗灌滴灌沟灌;胡敏素上层为沟灌滴灌渗灌,下层为渗灌滴灌沟灌。滴灌处理既能使0—40cm土层土壤有机碳含量保持较高水平,土壤腐殖质含量又高于沟灌、渗灌处理,这对于提升设施土壤肥力水平、保证番茄养分供应是有利的。     

土壤有机矿质复合体研究 Ⅶ．土壤结合态腐殖质的形成特点及其结合特征

本文系统剖析了熊毅－傅积平改进区分的土壤结合态腐殖质的形成特点，胡，富组成及其结合特征。结果表明：（１）用０．１ｍｏｌ／ＬＮａＯＨ及０．１ｍｏｌ／ＬＮａＯＨ＋０．１ｍｏｌ／ＬＮａ４Ｐ２Ｏ７混合液连续浸提的松结态（Ｈ１）和稳结态（Ｈ２）腐殖质所占的比例随土壤ｐＨ升高分别呈减少和增加趋势。统计分析显示Ｈ１与游离态铁，铝呈极显著的正相关，与交换性钙呈极显著负相关，Ｈ２则与交换性钙呈极显著正相关，而与游离     

湖南湖北两省H_6亚型禽流感病毒表面基因的序列分析

2008年至2009年间,在湖南和湖北两省的活禽市场中分离到了14株H6亚型禽流感病毒,为了解这14株病毒之间的分子特征和差异,我们运用PCR和测序鉴定对这14株病毒的NA基因进行了分型,并对其表面基因HA和NA进行序列测定及序列分析。14株H6亚型病毒中,H6N2亚型12株,H6N6亚型2株。序列测定和进化分析结果显示：DK/HN/284的HA基因与其它13株的HA差异性较大,差异性达到19.4%～20.2%,其余13株毒同源性在94.2%～99.9%;N2亚型NA基因的同源性在91.1%～99.9%,差异性比较大;两株N6亚型NA基因同源性为89.5%,差异明显。这些数据表明：不同毒株呈现一定的地域性差异。与我国周边其它地区的H6亚型禽流感毒株序列进行比较发现,只有DK/HN/284的HA基因与香港早期的毒株可能有着共同的来源,其余都与香港和韩国等的毒株有着较大的差异性,并且各个毒株的HA基因上潜在的糖基化位点和受体结合位点也有所不同,这些数据表明,这些毒株表现出明显的异源性。     

盐渍土熟化过程中腐殖质特性的研究

综合研究了河北省曲周试验区不同改良年代盐渍土的有机质含量、腐殖质组成、含氧官能团含量及腐殖质红外光谱特征等。研究结果表明：随着盐渍土治理年限的延长，施肥及管理水平的提高，从盐荒地经三代、二代到一代试验区，土壤有机质含量逐步提高；有机质的质量也得到改善，主要表现在：腐殖质总量提高、胡富比增大、E465／E665比值减少、官能团含量上升等。红外光谱分析结果表明：试验区土壤腐殖质是极相似的多官能团复杂体系，表现在胡敏酸的类型上，由盐荒地到一代试区土壤胡敏酸逐渐由Rp型向B型转变，表明土壤腐殖质向着结构复杂化、功能多样化方向发展。盐渍土有机质含量和质量逐渐接近当地非盐渍土——浅色草甸土的水平。     

腐植酸-纤维素复合农林保水剂的制备及性能

为了改善现有农林保水剂制造成本高,使用周期短,实用性差的现状,利用腐殖酸(HA)和羧甲基纤维素(CMC)通过交联反应制得一种新型的农林保水剂(HA—CMC复合吸水树脂)。研究了各原料最佳配比并进行反应条件优化,随后通过红外光谱和扫描电镜研究产物的物质组成特点和表面结构特征,并与已有的几种保水剂进行了性能比较。结果表明,制备该保水剂各材料最佳配比为CMC∶MBA∶HA∶AM∶KPS=1∶0.015∶0.2∶6∶0.2;产物中HA和CMC交联结果理想,产物表面结构符合一般高吸水材料的结构要求;在与其它4种保水剂的比较中证实:HA—CMC复合吸水树脂吸水能力明显优于其它3种保水剂,与表现最好的地津保水剂无显著性差异,其重复吸释水能力则远优于其它受试保水剂。     

秸秆深还对土壤腐殖质组成和胡敏酸结构特征的影响

以辽宁省阜新县试验基地培肥3年的草甸褐土为研究对象,设CK(不施秸秆)和CS(秸秆深还施用量为24 000 kg hm-2)2个处理,每个处理随机选取3个采样点,采集深度为0～20 cm和20～40 cm。采用腐殖质组成修改法提取水溶性物质(WSS)、胡敏酸(HA)、富里酸(FA)和胡敏素(Hu),研究秸秆深还对土壤腐殖质各组分含量的影响,并提取土壤胡敏酸(HA)固体样品进行结构表征。研究表明:秸秆深还更有助于表层土壤及其各腐殖质组分WSS、HA、FA和Hu有机碳含量的积累,分别较CK增加了33.11%、26.39%、11.09%、9.197%和18.55%,亚表层土壤WSS有机碳含量变化不显著,但HA和Hu的含碳量降低;表层和亚表层土壤PQ值的变化不显著;表层和亚表层土壤HA,缩合度变大,分子结构变复杂,芳香结构增加,热稳定性相对提高,亚表层土壤HA脂族结构稳定性增强。     

腐殖酸对外源砷在土壤中形态转化和有效性的影响

通过室内培养的方法,探讨腐殖酸(HAs)的两种活性组分——富里酸(FA)和胡敏酸(HA)及其不同比例(HA/FA)对土壤As形态转化及有效性的影响。结果表明,HAs的两种组分对土壤As的形态均具有显著影响,其影响程度和方向与其浓度、比例及外源As含量有关。FA和添加量≤1%C的HA能增加土壤交换态As(Ex-As)的含量,添加量≥3%C的HA能降低土壤Ex-As含量;两种组分都能降低土壤铝型As(Al-As)和铁型As(Fe-As)含量,增加残渣态As(Res-As)含量,FA比HA的作用效果更强;在等量(1%C)HAs条件下,HA/FA≥5/5时HAs能降低Ex-As含量,≤3/7时则能增加Ex-As的含量。HAs对土壤有效As的影响是其对As形态分配综合作用的结果,对土壤有效As贡献最大的是Ex-As和Ca-As;HA和添加量较高(≥5%C)的FA能够降低外源As在土壤中的有效性,而添加量较低(≤3%C)的FA能在一定程度上增加土壤As的有效性。因此,掌握有机物料合理的用量和活性组分比例是其作为土壤As活性调控剂的前提。     

百花山山地土壤中有机质的垂直分布规律

本文测定了北京百花山山地典型土壤剖面各发生层的有机质含量、腐殖酸组分、可见光谱,利用相关分析方法计算了有机质与海拔高度之间的相关系数。结果表明:有机质与海拔高度的相关系数为0.94,,呈显著相关水平;各剖面土壤腐殖质分析结果表明,该山地土壤的HA/FA值、E4/E6值随着海拔高度的升高而呈现上升趋势。     

腐植酸与Cd、Zn的络合特性研究

通过离子交换平衡法测定了胡敏酸的2 个不同分子量分级组分及富里酸与Cd 、Zn 络合反应的稳定常数及配位数,结果表明:随着腐植酸芳构化程度的提高,其与Cd 、Zn 的络合物的配位数及稳定常数也逐渐提高;当胡敏酸的分子量为48339 时,其对Cd 、Zn 的络合物稳定常数log K 值分别为5-20 和4-81 ,配位数分别为1-26 和1-15 ;而当分子量增加为78180 时,logK 值分别为5-68 和5-37 ,配位数分别为1-32和1-26 。富里酸 镉、锌的稳定常数( 分子量为2300) 分别为4-44 和4-42 ,配位数分别为1-29 和1-30 。这些结果表明,就减轻污染土壤中Cd 、Zn 对植物的危害而言,施用厩肥等芳构化程度较高的有机物比芳构化程度低的更为有效。     

Humus composition and humification degree of humic acids of alpine meadow soils in the northeastern part of the Qinghai–Tibet Plateau

The characteristics of humus composition are important for understanding the mechanism of carbon storage in the Qinghai–Tibet Plateau. The aim of this study was to characterize the quality of soil organic matter (SOM) in this region. Soil samples from four soil profiles in fenced study sites in the alpine grassland were collected at altitudes of 4200, 4000, 3800, and 3400 m, along the southwest facing slope in the Qilian Mountains. The humus composition and humification degree of the humic acid (HA) were determined by two methods: (1) extraction with 0.5% sodium hydroxide (NaOH) followed by 0.1 M sodium pyrophosphate (Na₄P₂O₇) (OH-PP method); and (2) treating once with 0.1 M hydrochloric acid (HCl) followed by extracting with 0.5% NaOH (Cl-OH method). Physico-chemical analysis revealed higher exchangeable cation content and higher base saturation ratios could be related to slightly acidic to neutral soils, which could be regarded as calcium (Ca)-rich soils. The amounts of combined-form HAs obtained by HCl pretreatment (HA_Cl – HA_OH; ?HA_Cl) were remarkably higher than those extracted with Na₄P₂O₇ (HA_PP), indicating that the combined form of HAs is mainly Ca. In addition, the proportion of HA_PP in the total HAs extracted with both NaOH and Na₄P₂O₇ (HA_OH + HA_PP) obtained in the OH-PP method increased with soil depth and decreasing elevation, indicating that HAs associated with aluminum (Al) and iron (Fe) were distinguished in the subsoils of lower elevation. Therefore, the formation of the organo-mineral complex may contribute to stabilizing SOM in the Qinghai–Tibet Plateau. Moreover, Type A-HA with the highest degree of humification was obtained from the deeper horizons with the Cl-OH method and almost all horizons by extraction with Na₄P₂O₇ in the OH-PP method. Further studies using various spectroscopic analyses are necessary to elucidate the chemical properties of SOM in this region.