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1.
太湖地区水耕人为土中漂白层的成因探讨 总被引：1，自引：0，他引：1
采集太湖地区4个具有漂白层的水耕人为土剖面(E-A1、E-A2、E-A3、E-A4)及1个发育于相同母质上的一般水耕人为土剖面作为参照(Ref),描述了土壤剖面的形态特征,分析了土壤颗粒组成、黏粒矿物组成、铁氧化物以及大量和微量元素等,并探讨了漂白层成因。5个剖面土壤颗粒组成以粉粒为主,在60%~75%之间,且剖面中各层次变异系数较小,小于10%;大量元素和微量元素在剖面各层次间变异系数也小于10%,指示漂白层与上覆和下伏土层发育在相似物质来源的土壤母质上;而E-A1剖面漂白层中较高的粉粒含量(75.04%)、较大的中细粉粒和中细粉粒/粗粉粒比值的变异系数(38.05%、61.85%)表明该剖面母质具有不均一性。说明E-A2、E-A3、E-A4、Ref剖面土壤性质的变化主要是由于成土作用形成的,而E-A1剖面土壤的性质变化除受成土作用影响外,还受沉积环境的影响。E-A2、E-A3、E-A4剖面的漂白层中蒙脱石和蛭石、粉粒和粗粉粒、SiO2、CaO、Zr等含量高于上下土层,而水云母和绿泥石、游离铁、Al2O3、Rb、Li、Ba、稀土元素(Rare earth element,REE)等则相反;同时,参照剖面亦有与E-A2、E-A3、E-A4剖面类似的特点,只是漂白作用出现在耕作层,不能定义为漂白层;而E-A1剖面的部分性质则显示出空间上的不一致性,其粉粒含量并非漂白层最高,而是随剖面土层深度向下越来越大。这些变异表明,太湖地区水耕人为土漂白层的形成,可以由黄土性泻湖相沉积物经过水耕过程中水分的周期性淹水和排干,通过机械淋洗和活性铁的淋溶而形成(剖面E-A2、E-A3、E-A4),也可以是母质沉积的过程中受湖水水面升降,导致机械淋溶,然后水耕过程叠加活性铁的淋溶而形成(剖面E-A1)。 相似文献
2.
中国水稻土的粘土矿物 总被引：1，自引：0，他引：1
应用X射线衍射法、差热分析法和化学分析法,鉴定了中国主要水稻土区的近六十个土壤标本。粘粒系小于2微米的部分。水稻土的粘土矿物组成与其母质有密切关系,在一般情况下,它继承了母质的矿物组成。不同母质发育的水稻土的主要粘土矿物组成可见表17。水稻土形成过程中粘土矿物组成的变化可分为三种不同的情况:富有含钾矿物的母质发育成水稻土时脱钾作用明显,粘土矿物有较大的变化。中量含钾矿物的母质发育成水稻土后,粘土矿物组成的变化很小。没有含钾矿物的砖红壤发育的水稻土,在成土过程中有明显的复硅和复盐基作用,在老水稻土中,三水铝石减少,同时出现了濛脱类矿物。水稻土表层与心土层的粘土矿物组成,只有少数土壤有明显差别,大多数看不出差别来。水稻土的潜育层与其上部土层比较起来,除氧化铁含量有显著减少以外,粘土矿物组成基本上是相同的。因此潜育作用的实质主要是部分游离氧化铁的还原,淋失,而粘土矿物并未遭受特别强烈的破坏。根据粘土矿物的异同,暂时将中国水稻土分为四个地理区:以高岭类(三水铝石)为主的华南水稻土区,也就是热带和南亚热带双季稻地区,以高岭类(云泰、濛脱类)为主的华中水稻土区,也就是中亚热带双季稻地区,以濛脱类和云泰(高岭类)为主的长江中、下游水稻土区,也就是北亚热带稻麦两熟地区,以云泰(濛脱类)为主的华北水稻土区。由于水稻土的粘土矿物组成仍受其前身——地带性土壤的影响,因此上述各区的粘土矿物组成,也反映出地带性的特征。 相似文献
3.
应用穆斯堡尔谱和X射线法研究红壤性水稻土的氧化铁矿物 总被引：1，自引：1，他引：1
应用穆斯堡尔谱和X射线法分析研究红壤性水稻土的氧化铁矿物,研究结果表明,红壤性水稻土的氧化铁矿物组成、特性及其形成转化与起源土壤具有明显的差异。水稻土的成土条件不利于赤铁矿的形成。红壤的粘粒氧化铁矿物以赤铁矿和高铝替代(>20摩尔%)的针铁矿为主。经淹水种稻后,赤铁矿逐渐被转化为低铝替代的针铁矿或其它形态氧化铁。渗育型水稻土P层的赤铁矿含量比相应的母土低,其针铁矿铝替代量较其它水型的水稻土高。而潴育型水稻土W层和潜育型水稻土G层粘粒氧化铁矿物均以针铁矿为主,其铝同晶替代量低(<15摩尔%),且颗粒细小,结晶度较低。这些结果反映了水稻土的成土条件和发生特点,同时对水稻土发生分类具有重要的意义。 相似文献
4.
闽北地区水耕人为土的发生与系统分类研究 总被引：3，自引：0，他引：3
水耕人为土是在水耕条件下形成的具有人为诊断层的独特土壤类型。对采自福建省北部的13个水耕人为土典型剖面进行了土壤形成条件调查和土壤理化性状鉴定,明确了其发生学特性,并依据《中国土壤系统分类检索(第三版)》,鉴定了其诊断层和诊断特性,确定了研究土壤剖面在中国土壤系统分类中的归属。鉴定出的诊断层主要有水耕表层、水耕氧化还原层、漂白层、黏化层;诊断特性主要有人为滞水土壤水分状况、潜育特征、盐积现象、氧化还原特性。13个剖面可分别归属为弱盐潜育水耕人为土、普通潜育水耕人为土、漂白铁聚水耕人为土、普通铁聚水耕人为土、普通简育水耕人为土5个亚类。 相似文献
5.
成都平原水稻土中铁的分异特点 总被引：2，自引：0，他引：2
本文研究了成都平原发育于岷江冲积物、紫色土沉积物和黄壤残积物三种不同母质的六个主要水稻土剖面中各种形态氧化铁含量及其在剖面中的分异特点,探讨了各种形态氧化铁之间的关系及其与环境条件、成土母质的关系。此外,根据全铁含量在剖面中的分异,讨论了发生层的形成。 相似文献
6.
浙西石灰岩发育土壤中氧化铁矿物组成及特性的研究 总被引：2，自引：1，他引：2
本计浙西地区４个具不同颜色的石灰岩发育土壤的氧化铁矿物组成和特性进行了研究。结果表明，在亚热带生物气候作用下，这些土壤已经经历了一定的风化，从氧化铁游离度来看；风化强度红壤性土（油红泥）〉棕色石灰土（油红黄、油黄泥）〉黑色石灰土（碳质黑油泥）。氧化铁矿物类型与土色存在一定的关系，油红泥含较高的赤铁矿，土色以红色和棕红色为主；油红黄 油黄泥主要以针铁矿为主，赤铁矿含理较低土色以黄棕色为主；碳质黑油 相似文献
7.
本文以辽宁省浑河在不同历史时期形成的阶地上的黄土状物质发育的土壤为研究对象,通过对剖面形态学特征、基本理化性质和母质均一性判定等研究,探讨了浑河三级阶地白浆化土壤的白土层特征及其形成机制。结果显示:(1)土壤粉粒中的稳定元素钛与锆分析结果表明在三级阶地上的21-003、21-009、07和21-076剖面和二级阶地上的21-001、21-200、03和04剖面的母质均一;(2)由于土体发育程度不同,一级阶地土体中无淀积层;二级阶地土体中有淀积层且无白土层,尚未出现白浆化现象;三级阶地土体中淀积层和白浆化现象明显,出现了白土层,其形成以黏粒的机械淋溶和潴育淋溶为主;三级阶地上土壤比二级阶地和一级阶地发育时间长,但尚未达到漂白层的标准。 相似文献
8.
三江平原白浆土发生学特性 总被引：1，自引：1，他引：1
本文对三江平原三个典型白浆土剖面的理化性质、土壤微形态和矿物学性质的研究，探讨了白浆土的发生学特性。土体中Ｚｒ／Ｓｒ和Ｔｉ／Ｚｒ比率的变异系数表明，所研究的土壤剖面其成土母质岩性是连续的。典型白浆土具有一个松软的表土层、一个漂白层和一个相当厚的粘化淀积层。研究还表明，粘粒的悬浮迁移是白浆土的主要成土过程。表层和白浆层在成土过程中有Ｆｅ－Ｍｎ结核形成，且是原地形成的，其Ｆｅ、Ｍｎ明显源于原生矿物的风 相似文献
9.
我国红壤中氧化铁形态及其特性和功能 总被引：20，自引：1，他引：20
研究结果表明，红壤类土壤富含氧化铁，其中以游离氧化铁为主，其游离度反映了一定的地带特征。在所研究的土壤中，氧化铁和氧化铝是带可变正电荷的氧化物型表面，而氧化硅是带可变负电荷的表面。 相似文献
10.
鄂、湘两省土地土壤粘粒矿物的研究——Ⅱ.莽山北坡土壤中的粘粒矿物 总被引：1，自引：0，他引：1
对莽山北坡不同海拔高度的5个土壤剖面15个土样的粘粒矿物进行了X射线衍射分析和粘粒氧化物的化学选择溶提测试,结果表明:(1)莽山土壤中粘粒矿物组合的垂直变化明显。海拔500m以下的红壤、黄红壤的粘土矿物以1:1型高岭为主,粘粒氧化物中有较多的晶质氧化铁和热碱溶性氧化硅。海拔850m以上的黄壤、暗黄棕壤和山地灌丛草甸土的粘土矿物以2:1型的14×10-10m过渡矿物和水云母为主,粘粒氧化物中有较多的无定形氧化铁、铝和三水铝石。(2)随海拔升高,土壤粘粒的硅铝率、氧化铁的游离度变幅不大,而氧化铁的活化度和各种氧化铝的富集明显提高。根据这些结果,结合莽山土壤的风化威土的条件与过程,讨论了莽山垂直带土壤中粘土矿物和氧化物的分布与演化过程的特点。 相似文献
11.
西藏高原突起于我国西南,绝大部分地面的海拔高度在4000米以上,为世界上最高的大高原。它大致在第三纪开始形成,后来曾受第四纪冰川的深刻作用,高山顶部至今仍是冰川的活动场所[1,2]。高原为昆仑山、唐古拉山、喜马拉雅山和横断山等大山脉所盘踞。 相似文献
12.
G. lvarez Arteaga N.E. García Caldern P.V. Krasilnikov S.N. Sedov V.O. Targulian N. Velzquez Rosas 《Geoderma》2008,144(3-4):593-612
The soils of montane cloud forests (MCF) are still insufficiently studied. A number of researchers report Podzols to be the main soil group for MCF ecosystems; however, a great deal of contradictory data exists. We studied an altitudinal sequence of soils formed on ferrous chlorite shale under natural MCF vegetation in Sierra Juárez, Southern Mexico, from 1500 to 2500 m asl. The soils of the upper part of the toposequence were Folic Stagnic Podzols, with inclusions of Folic Stagnosols in local depressions, while the soils of the lower part of the toposequence were Folic Cambisols (Humic, Hyperdystric). All the soils in the toposequence were extremely acid, and had thick organic surface horizon. Mineral horizons of all soils were poor both in exchangeable and total reserves of bases; the bases were concentrated mainly in organic topsoil. With decreasing altitude both the thickness of albic horizons, the depth of the maximum acid oxalate-extractable Fe and Al concentrations, and the difference in clay content between the eluvial and illuvial horizons decreased. In the upper part of the toposequence the composition of soil clays was similar to that of parent material (chlorite and mica), with some mixed-layered 2:1 minerals. However, gibbsite and kaolinite were also present in the soils of the other site within the same upper MCF belt. The phenomenon was ascribed to parent material heterogenity. In the medium and lower parts of the toposequence gibbsite and kaolinite were the dominant minerals. We consider that the main pedogenic processes in the study area are raw humus accumulation, weathering in situ, podzolization, and iron reduction due to water stagnation in mineral topsoil. The intensity of weathering decreases, while the extent of water stagnation increases with altitude. To a great extent the genesis and altitudinal distribution of the soils in the MCF depends on parent material. 相似文献
13.
The mineralogy of the clay fractions separated from the B horizons of two Hydrandepts (Hilo and Akaka soils), a Torrox (Molokai soil) and a Humitropept (Kolekole soil) was determined by a combination of methods.The Hydrandept B horizons were characterized by predominance of hydrous non-crystalline alumina and iron oxides associated with considerable amounts of humus and with very small amounts of silica. Allophane, allophane-like constituents and imogolite were present but in minor amounts. Gibbsite, goethite, chlorite and illite were also present as accessory minerals.The Torrox and Humitropept B horizons were characterized by predominance of kaolinite, hematite and goethite. The iron oxide minerals were present as fine particles (40–80 A diameter) often clustered to form larger aggregates. Neither imogolite nor allophane and allophane-like constituents were detected. Considerable amounts of dithionite-citrate soluble Al and humus were, however, present in the Humitropept B horizon, which may reflect the effect of an admixture of volcanic ash to the parent material. 相似文献
14.
In the northern forest-steppe of European Russia, under the conditions of surface waterlogging (freshwater) and a stagnant-percolative
regime, gleyic podzolic chernozem-like soils with thick light-colored eluvial horizons are formed. These horizons are close
or similar to the podzolic horizons of bog-podzolic soils in many properties of their solid phase. They are bleached in color
and characterized by the removal of Ca, Mg, Fe, Al, and Mn and the relative accumulation of quartz SiO2. These soils differ from leached chernozems in their acid reaction and very low CEC, the presence of Fe-Mn concretions and
coatings, and the significant decrease in the clay content in the A2 horizon as compared to the parent rock.
The soils studied differ significantly from loamy podzolic and bog-podzolic soils by the composition of the clay minerals
in the A2 horizons: (1) no essential loss of smectite minerals from this horizon was found as compared to the rest of the
solum, (2) pedogenic chlorites (HIV and HIS) are absent, and (3) the distinct accumulation of illites is observed as compared
to the subsoil and parent material, probably, due to the process of illitization. 相似文献
15.
Characteristics of Clay Minerals in Podzols and Podzolic Soils 总被引：1，自引：0，他引：1
Yasuo Kitagawa 《Soil Science and Plant Nutrition》2005,51(2):151-158
The clay minerals in Podzols and podzolic soils developed under coniferous forests in the Subarctic and Cool-temperate zones are characterized by the predominance of smectite and/or mica-smectite interstratified minerals in the eluvial horizons and chlorite-vermiculite intergrade in the illuvial horizons. A large amount of vermiculite is present in the eluvial horizons of some podzolic soils in the Cool-temperate zone. The illuvial horizons of these soils also contain free iron oxides such as goethite. Imogolite and allophane are present in the illuvial horizons of several soils derived from volcanic ashes. It is suggested that the critical bioclimate for the release of interlayered aluminum from the 2:1-type minerals lies between the Cool- and Warm-temperate zone. In the eluvial horizons of Podzols and podzolic soils, mica minerals and chlorite, as primary minerals, have been transformed to smectite through the pedogenic process. Based on previous studies on the structure and degradation of the dioctahedral mica minerals, it is considered that smectite is transformed from 1M-type mica minerals directly, and from 2M-type mica minerals via mica-smectite interstratifled minerals. The formation of a smectite lattice in the eluvial horizon should be a clay-mineralogical indicator of podzolization. 相似文献
16.
The pH-dependence of surface charge density of three iron oxides and the clay fraction of five horizons of a variable-charge soil has been studied by adsorption of potential-determining ions (p.d.i.) and by adsorption of electrolyte ions. The general trend of results for iron oxides can be satisfactorily explained by a model which considers a three-plane distribution of electric potential. When the model is applied to soil clays the outcome is less satisfactory and, although their charge properties seem to be largely determined by their high content of minerals with variable charge surfaces, the presence of minerals with a permanent charge (clay minerals) should be considered when explaining the particular data, even for those horizons where clay minerals are present in low proportions. 相似文献
17.
18.
Characteristics of fragipan B horizons developed on different parent material in North-Western Italy
E. Raimondo G. Falsone M. D’Amico S. Stanchi L. Celi E. Bonifacio 《Archives of Agronomy and Soil Science》2019,65(3):308-321
A Fragipan (Bx) is a soil horizon hard when dry and brittle when moist, that undergoes slaking upon water immersion, forming a barrier to roots and limiting land use. Brittleness and slaking depend on soil porosity and particle arrangement, but still no agreement exists on the inorganic components responsible for such arrangement. We hypothesized that the same kind of particle arrangement may originate from different soil components, ultimately depending on the lithology of parent material, and evaluated the soil and clay characteristics that best differentiate Bx from B horizons. Thirty-six samples were taken from Typic Fragiudalfs developed on the two sides of an alluvial fan characterized by different amounts of ultramafic materials. Discriminant Analysis evidenced that pedogenic Fe oxides were fundamental in discriminating Bx from B horizons on pure ultramafic parent material, while clay mineralogy was more important in soils with less ultramafic materials. In the first case, the association between clay minerals and self-assembling oxides systems may lead to brittleness, while in the second case the higher abundance of kaolinite may contribute to weak associations between pH-dependent sites and negatively charged surfaces. The only common feature to fragipans on both river sides was a higher degree of weathering. 相似文献