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1.
The effects of the migration of two soil constituents into illuvial horizons is described by a set of equations. Differential movement of clay fractions during illuviation causes changes in the fine to total clay ratios in A and B horizons. A mathematical model is used for the interpretation of clay fraction data in order to estimate the degree of profile development, the amounts of fine and total clay which have moved, and to determine the original composition of the parent material. No bulk density data of the soil horizons are necessary for the computation. The equations can be programmed on desk calculators. Comparison with measurements on Alfisols in temperate regions was found to be satisfactory. 相似文献
2.
The bulk density, available water (Aν), air capacity (Cα), and retained water capacity (θν) were determined for 158 A, B, and C horizons of field soils. Clay (< 2 μm) and silt (2=60 μm) were also determined. Statistical analysis of the results demonstrated that bulk density exerts a profound influence on Aν, Cα, and θν, but the effect varies between texture groups and horizons. Significant negative correlations were obtained between bulk density and Cα for most texture and horizon groups. In B and C horizons Aν and θν also decrease with increasing density, whereas in A horizons Aν and θν tend to increase with bulk density except in silty soils. Within a limited range it is feasible to control these parameters by using field techniques to achieve optimum bulk density for particular soils. 相似文献
3.
利用X射线衍射法估算了福建省221个土壤样品中粘粒云母含量并讨论了与粘粒云母含量变化有关的因素。结果表明母质是影响粘粒云母含量的主要因素。海积物、河积物及页岩上发育的土壤粘粒云母含量一般较高;基性岩上发育的土壤粘粒云母含量一般较低。风化度较高的赤红壤、红壤、黄红壤和黄壤等土类的粘粒云母含量一般较低。风化度较低的C层的粘粒云母含量一般较B层和A层高,但异源母质的堆积可以使A层粘粒云母含量高于B层和C层。 相似文献
4.
Clay-with-flints rests on remnants of the exhumed sub-Eocene surface, which is shown to be an important geomorphological feature of the West Sussex Downs. Mineralogical and other soil profile studies indicate that the deposit has developed by the action of cryoturbation and soil-forming processes on a thin cover of Reading Beds clay left on the sub-Eocene surface during the southward recession of a small Eocene escarpment. Two horizons corresponding to Clay-with-flints sensu stricto of Loveday (1962) are recognized. The basal horizon is composed partly of insoluble Chalk residue, but mainly of clay moved down from overlying horizons into the spaces left on dissolution of the Chalk at the junction of the Chalk with the base of the Clay-with-flints. The upper horizon is composed of material from weathered remnants of Reading Beds clay, thoroughly mixed by cryoturbation with flints, other insoluble Chalk residue and clay from former basal horizons. The surface horizons of the soils often include additions of loess. 相似文献
5.
The chemical and microbial properties of afforested mine soils are likely to depend on the species composition of the introduced
vegetation. This study compared the chemical and microbial properties of organic horizons and the uppermost mineral layers
in mine soils under pure pine (Pinus sylvestris), birch (Betula pendula), larch (Larix decidua), alder (Alnus glutinosa), and mixed pine–alder and birch–alder forest stands. The studied properties included soil pH, content of organic C (Corg) and total N (Nt), microbial biomass (Cmic), basal respiration, nitrogen mineralization rate (Min-N), and the activities of dehydrogenase, acid phosphomonoesterase,
and urease. Near-infrared spectroscopy (NIR) was used to detect differences in the chemical composition of soil organic matter
under the studied forest stands. There were significant differences in Corg and Nt contents between stands in both O and mineral soil horizons and also in the chemical composition of the accumulated organic
matter, as indicated by NIR spectra differences. Alder was associated with the largest Corg and Nt accumulation but also with a significant decrease of pH in the mineral soil. Microbial biomass, respiration, the percentage
of Corg present as Cmic, Min-N, and dehydrogenase activity were the highest under the birch stand, indicating a positive effect of birch on soil
microflora. Admixture of alder to coniferous stand increased basal respiration, Min-N, and activities of dehydrogenase and
acid phosphomonoesterase as compared with the pure pine stand. In the O horizon, soil pH and Nt content had the most important effects on all microbial properties. In this horizon, the activities of urease and acid phosphomonoesterase
did not depend on microbial biomass. In the mineral layer, however, the amount of accumulated C and microbial biomass were
of primary importance for the enzyme activities. 相似文献
6.
THE EFFECT OF THE CONCENTRATION AND MOVEMENT OF SOLUTIONS ON THE SWELLING, DISPERSION, AND MOVEMENT OF CLAY IN SALINE AND ALKALI SOILS 总被引：1，自引：0，他引：1
Changes in permeability of a soil containing montmorillonite, and the swelling of orientated aggregates of extracted clay have been measured for a range of exchangeable sodium percentages and electrolyte concentrations. The concentrations at which clay moved out of the soil in the percolates have been found and compared with the concentrations at which aggregates dispersed in stationary solutions, and the concentrations at which soil suspensions dispersed when shaken. The results indicate that: (a) permeability begins to decrease at the same concentration as the clay begins to swell, (b) the changes in permeability are directly controlled by the swelling of clay until clay dispersion and movement begins, (c) the concentration at which clay disperses depends on the mechanical stress applied, (d) when small mechanical stresses are applied, the proportion of the clay which swells and disperses depends directly on the exchangeable sodium percentage, and (e) large mechanical stresses may disperse most of the clay even at low exchangeable sodium percentages. 相似文献
7.
A contrasting occurrence of clay minerals was found within a soil profile which was derived from volcanic materials in the suburbs of Fukuoka-city, Northern Kyushu. The soil profile is located on an isolated terrace, and the morphological characteristics of the soil correspond exactly to Andosols, so-called Kuroboku soils or Humic Allophane soils. The clay fraction of upper horizons of the soil consists largely of alumina-rich gel-like materials, gibbsite, and layer silicates such as chlorite and chloritevermiculite intergrades, while that of lower horizons is composed of allophane and gibbsite or halloysite. There was no positive indication of allophane in the upper horizons. Corresponding with the clay mineralogical composition, quartz is abundant in the fine sand fraction of the upper horizons, while the mineral is very scarce or none in the lower horizons, suggesting a close relation between the petrological nature of parent volcanic materials and the mineralogical composition of weathering products. The dominant clay mineral in the volcanic 1.10il might be dependent on the petrological nature of parent materials, and allophane is mostly formed from andesitic materials, and alumina-rich gel-like materials and layer silicates have come from quartz andesitic materials. Allophane would transform to gibbsite or halloysite according to weathering conditions, and aluminarich gel-like materials change to gibbsite under a well-drained condition. The soil materials have been so greatly weathered that some horizons contain gibbsite of even more than 40 per cent or halloysite over 70 per cent. The morphology and mineralogy are quite similar to so-cailed “non-volcanic Kuroboku soils.” 相似文献
8.
Few studies on free lipids in total solvent extracts from soil clay fractions directly measured by gas chromatography–mass spectrometry (GC/MS) have been reported so far. In this study, we aimed to examine the free lipids in the clay fraction separated from a Fluvisol profile on which sewage sludge was deposited 6 years ago and provide information on the sources, diagenetic processes and organic pollutants derived from the sludge. Clay fractions were separated from the four horizons of a Fluvisol and analysed for the biochemically stable lipid pool. The GC/MS analysis of the lipid fraction showed that lipid signatures were dominated by alkanes (C17–C33), alkanoic acids (C12–C18), alkanols (C14–C30), aromatic acids and phthalate esters. Sources of lipids show predominant bacterial contribution as shown by the alkane, fatty acids and n-alkanol distributions. The preservation of lipids of microbial origin in the clay fraction was revealed by the presence of even number, branched alkanes and short-chain and branched fatty acids. These results imply that similar pedogenic processes took place in this soil profile affected by hydromorphic conditions with some quantitative changes in the clay lipid compositions between different soil horizons. Some aromatic acids and xenobiotics such as phthalates were detected in the lipid extracts of the clay fractions in depth (0–85 cm) of the soil profile, which has implications for pollution of soils and ground waters in situations of sewage sludge deposition. 相似文献
9.
The objective of this study was to evaluate the relationship between clay mineralogy, specific surface area (SSA) and micromorphology in polygenetic Konza soil series. Physical, chemical and mineralogical analyses were performed on disturbed soil samples, and micromorphological investigations of selected horizons were done on undisturbed soil samples. X-ray diffraction indicated that lower part of each parent materials has more mectite and less clay mica content than that of the upper horizons in each parent material. Greater amounts of smectite can be attributed to transformation product of the clay mica in to smectite, eluviation from upper horizons or originated from parent material. Specific surface area of upper horizons in each parent material tended to increase to lower horizons. Clay content gradually increased from surface (21%) to the lower part (～48%) of the solum. Clay in Bt horizons had strong birefrengent, sharp boundary, and strong orientation pattern. SSA, clay content increase, clay mineralogy and oriented clay features agreed to one another. Therefore, this relationship gives opportunity to make predictions on extend of SSA and related soil processes by looking at one of these features. 相似文献
10.
11.
Data on the mineralogical composition of clay in soils of solonetzic complexes of the Priobskoe Plateau and the Kulunda and Baraba lowlands have been generalized. The parent materials predominating in these regions have loamy and clayey textures and are characterized by the association of clay minerals represented by dioctahedral and trioctahedral mica–hydromica, chlorite, kaolinite, and a number of irregular interstratifications. They differ in the proportions between the major mineral phases and in the qualitative composition of the minerals. Mica–hydromica and chlorites with a small amount of smectitic phase predominate on the Priobskoe Plateau and in the Kulunda Lowland; in the Baraba Lowland, the portion of mica–smectite interstratifications is higher. An eluvial–illuvial distribution of clay fraction in solonetzes is accompanied by the acid–alkaline destruction and lessivage of clay minerals, including the smectitic phase in the superdispersed state. This results in the strong transformation of the mineralogical composition of the upper (suprasolonetzic) horizons and in the enrichment of the solonetzic horizons with the products of mineral destruction; superdispersed smectite; and undestroyed particles of hydromica, kaolinite, and chlorite from the suprasolonetzic horizons. A significant decrease in the content of smectitic phase in the surface solodic horizons of solonetzic complexes has different consequences in the studied regions. In the soils of the Priobskoe Plateau and Kulunda Lowland with a relatively low content (10–30%) of smectitic phase represented by chlorite–smectite interstratifications, this phase virtually disappears from the soils (there are only rare cases of its preservation). In the soils of the Baraba Lowland developed from the parent materials with the high content (30–50%) of smectitic phase represented by mica–smectite interstratifications, the similar decrease (by 10–20%) in the content of smectitic phase does not result in its complete disappearance. However, the smectitic phase acquires the superdispersed state and the capacity for migration. 相似文献
12.
《Communications in Soil Science and Plant Analysis》2012,43(5):345-351
Abstract Alkaline‐soluble, acid‐precipitable organic matter from the Ah and Bm horizons of Chernozemic soils developed on four parent materials in each of three soil zones was analyzed for total and carboxyl acidity, and methoxyl groups. The values are expressed as meq/g dry ash‐free organic matter. Total acidity generally was higher in the Black Chernozems than in the Brown Chernozems and higher in the Bm horizon than in the Ah horizon. The distribution of carboxyl acidity between the Ah and companion Bm horizons of individual soils appeared to be related to texture and rainfall. The. methoxyl group content of the Brown Chernozems was larger than that of the .Dark Brown Chernozems, which in turn had a larger methoxyl group content than that of the Black Chernozems. It was concluded that the organic matter in the Ah horizons of the Brown Chernozems was not as humified as that of the Black Chernozems. The pH value and a minimum clay content are possible determining factors as to the amounts of methoxyl carbon present. 相似文献
13.
D. C. BAIN 《European Journal of Soil Science》1977,28(1):144-164
The mineralogy of 14 chloritic soils of various drainage classes developed on different parent materials from the Loch Awe area of Argyllshire, Caithness, and the Southern Uplands reveals only minor variations'in clay mineralogy with profile depth, the frequent presence of primary minerals indicating that all the soils are immature, and that weathering is at an early stage. Iron-rich chlorite generally persists throughout the profiles, varying little in amount or chemical composition between horizons; where identifiable, the polytype is II b. Oxidation of iron modifies the thermal characteristics of the chlorite in all the freely-drained soils but usually only in the surface horizons of gleys. Irrespective of soil type or drainage class, in most profiles chlorite weathers only slightly, probably by vermiculitization around the edges of flakes. 相似文献
14.
四川盆地紫色土肥力与母质特性的关系 总被引：7，自引：0，他引：7
紫色土在四川盆地分布最广,占全省总面积的28%,占耕地总面积的68.7%,是该省粮食生产基地,粮食产量约占全省总量的70%.这种土壤除种植粮食作物外,还适宜种植蔗、棉、油、桑和水果.紫色土生产潜力极大,但也存在不少问题.从三十年代以来,许多土壤学者对紫色土进行过一系列研究,一致认为紫色土肥力与母质特性关系密切.本文以底土或岩石风化碎屑(即母质,C)为基本材料,同时用表土(A)和岩石(R)作辅助样品,研究了紫色土肥力与母质特性的关系. 相似文献
15.
Peter Kühn Konrad Billwitz Albrecht Bauriegel Dieter Kühn Wolf Eckelmann 《植物养料与土壤学杂志》2006,169(3):420-433
Fahlerden dominate large areas of the young and old moraine landscapes of N and E Germany. Fahlerden (part of Fahlerden corresponds to Albeluvisols) and their transitional subtypes are supposed to have a higher intensity of clay illuviation than Parabraunerden (Luvisols). Besides this macroscopic feature reflecting periglacial influence, micromorphological features such as lenticular platy microstructure, vesicles, and fragments of clay coatings in Bt streaks document the initiation of Fahlerde genesis, which began in the Late Glacial. A model of Fahlerde genesis chronologically connects sedimentological and periglacial processes, vegetation development, and soil‐forming processes like decalcification, clay illuviation, and humification. The classification criterion of larger differences in clay contents between E and Bt horizons to distinguish Fahlerden from Parabraunerden needs to be reconsidered, because most Fahlerden have developed in stratified parent material in periglacially influenced landscapes. The interpretation of a soil data base listing data of both soil types distributed in Brandenburg demonstrates that the difference in clay contents between E and Bt horizons may even be smaller in Fahlerden than in Parabraunerden. 相似文献
16.
E. A. Susyan N. D. Ananyeva E. G. Gavrilenko O. V. Chernova M. V. Bobrovskii 《Eurasian Soil Science》2009,42(10):1148-1155
In the mineral horizons of the soils under different southern taiga forests (oak, archangel spruce, and aspen in the Kaluzhskie
Zaseki Reserve of Kaluga region and the green moss spruce and spruce-broadleaved forests of the Zvenigorod Biological Station
of Moscow State University in Moscow region), the carbon content in the microbial biomass (Cmic), the rate of the basal respiration (BR), and the specific microbial respiration (qCO2= BR/Cmic) were determined. The Cmic content was measured using the method of substrate-induced respiration (SIR). In the upper humus horizons of the soils, the
Cmic content amounted to 762–2545 μg/g and the BR ranged from 1.59 to 7.55 μg CO2-C/g per h. The values of these parameters essentially decreased down the soil profiles. The portion of Cmic in the organic carbon of the humus horizons of the forest soils was 4.4 to 13.2%. The qCO2values increased with the depth in the soils of the Biological Station and did not change in the soils of the Reserve. The
pool of Cmic and Corg and the microbial production of CO2 (BR) within the forest soil profiles are presented. 相似文献
17.
《Communications in Soil Science and Plant Analysis》2012,43(3-4):509-519
Abstract Potassium (K) availability was assessed in 21 soil samples from four different parent materials (alluvium, iron pan materials, Nupe sandstones, and colluvial materials) across the subhumid zone of Nigeria. It was found that the Nupe sandstone soils gave the lowest proportion of the various forms of K with respect to total K in the topsoil. While water‐soluble K was the lowest in the soils of all the parent materials, one normal hydrochloric acid (1 N HCl)‐extractable K was the highest in the soils of all the parent materials. The one normal ammonium acetate (1 N NH4OAc)‐extractable K (exchangeable K) was correlated (P<0.05) with exchangeable calcium (Ca) and magnesium (Mg) in the alluvial, iron pan material and colluvial material soils and with clay in the soils of all the parent materials. The K fixed in the 42 days of incubation was highly correlated (P<0.01) with the K added in the colluvial material soils. 相似文献
18.
S. P. DIXIT 《European Journal of Soil Science》1978,29(4):557-566
A method is described for measuring the relative mobility (RM) of colloidal suspensions. It was used to assess the potential mobility of clay in the horizons of 12 profiles from Belgium, Bolivia, Brazil and India. The colloid from surface horizons of soil was always more mobile than that from deeper layers. The values of relative mobility differed between profiles and appeared to give a useful indication of potential clay migration under natural conditions. 相似文献
19.
本文研究了中南地区不同纬度带花岗岩母质发育的黄棕壤、红壤、砖红壤的胶体表面性质与粘土矿物组合、14×10-10m矿物、氧化物的关系。结果表明:(1)黄棕壤、红壤、砖红壤粘粒的阳离子交换量、比表面和内表面占总表面的比例依次减小,这与其高岭石、粘粒氧化物含量依次增加,14×10-10m矿物含量依次减少有关,且也与14×10-10m矿物在黄棕壤中主要是蛭石,在红壤中主要是14×10-10m过渡矿物,砖红壤不含14×10-10m矿物的结论相符合。(2)在其他矿物类型和含量相近下,14×l0-10m矿物是蛭石的土壤与14×10-10m矿物是14×10-10m过渡矿物的土壤相比,前者的阳离子交换量、比表面、内表面占总表面的比例比后者高些,但土壤的活性酸度弱些,交换性铝含量比后者低些。 相似文献
20.
《Communications in Soil Science and Plant Analysis》2012,43(9-10):1343-1355
Abstract The cation exchange capacity (CEC) at pH 7 was measured for samples of 347 A horizons and 696 B horizons of New Zealand soils. The mean CEC was 22.1 cmolc/kg for the A horizons and 15.2 cmolc/kg for the B horizons. Multiple regressions were carried out for CEC against organic carbon (C), clay content, and the content of seven groups of clay minerals. The results, significant at p <0.001, were consistent with most of the CEC arising from soil organic matter. For the samples of A horizon, the calculated CEC was 221 cmolc/kg per unit C and for the B horizons was 330 cmolc/kg C. There was also a contribution from sites on clay minerals. Multiple regression indicated that smectite had a higher CEC (70 cmolc/kg) than other minerals but it was not as high as that of type smectites; kaolin minerals had the lowest CEC. There was a significant effect of interaction between organic matter and some clay minerals on the CEC. Samples from B horizons containing allophane had lower CEC than those not containing allophane which is consistent with allophane reacting with carboxyl groups on organic matter. For the samples from the A horizons, however the CEC was higher when allophane was present. 相似文献