Paleosols of the southern coastal plain of Israel

Paleosols of the S coastal plain of Israel were studied in a characteristic sequence situated in the Ruhama badlands area. At the upper part of the sequence, there is a Loessial Arid Brown Soil (Calciorthids), characteristic of the mildly arid climate of the area. The soil has two calcic horizons and four clayey layers alternating with four calcareous layers which are beneath them. Physical, chemical, and magnetic‐susceptibility data and micromorphological evidence indicate that each clayey layer together with the calcareous layer beneath it forms a single pedogenic unit. These units are similar to modern Grumusolic soils (Xeric Paleargids or Xererthic Calciargids) that occur in the semiarid belt of the S coastal plain and develop on eolian‐dust parent material. The calcareous layers are in fact calcic horizons formed by leaching of the carbonates from the clayey layers and accumulated in the form of in situ carbonate nodules. The leaching of the carbonates is not complete; they were never completely leached in the past. This feature together with a typical brown color is also characteristic of the modern soils developed in the semiarid water regime of the area. The four superimposed paleosols represent four cycles. It is suggested that they were formed in two phases. During a dry environment, a short phase of rapid eolian‐dust accumulation prevailed, followed by a stable phase of soil development in a somewhat wetter climate. Dating by optically stimulated luminescence and previous dating by ¹⁴C in the area suggest that the upper two paleosol cycles belong to the Last Glacial period whereas the other two cycles are of an earlier age. The magnetic‐susceptibility values decrease with age and react different from temperate areas. Below the four cycles, two totally leached paleosols developed on sandy parent material occur. Both paleosols have a reversed magnetic polarity and are hence older than 780 ky BP. The upper one is a Brown Mediterranean soil, and the lower one is a Red Mediterranean soil. Thin‐section evidence suggests that they formed on terrestrial sand dunes.     

A micromorphological analysis of regrouping phenomena in some turkish soils

Both macromorphology and micromorphology of four profiles from the Turkish part of the Balkan Peninsula have been studied. The primary aim was to test applicabilities of the concept of “regrouping phenomena”. To do this, profiles were examined in the field and thin sections of individual horizons were subsequently studied in the laboratory. Part of the examination was done with Quantimet equipment. Emphasis was given to characteristics of horizons that could indicate one or more of pedotranslocations, pedoturbations, pedocompactions and pedotransformations. Evidence for past operations of all four kinds of processes were found in the profiles, with differences from one to another.Orthic, mainly plane ferriargillans, papules, calcitans, matrans and neomatrans form a strong indication of pedotranslocations only in the Noncalcic Brown soils. The occurrence of papules in the clayey B horizons and argillans in well-preserved condition in the lighter-textured C horizons show that there has been a shift in the balance among pedogenetic processes in these soils.The decrease of visible porosity around zoogenic tubes, presence of skew and craze planes, and aggregation patterns show that pedocompactions are intensive processes in all the soils. Because of the clay content of the soil and climate of the area, pedoturbations were especially evident in the Vertisol profile.Occurrence of ferriargillans formed in situ (weathering cutans) and a strong expression of sepic fabrics are features of pedotransformations in all the soils.     

Soil altitudinal sequence on base-poor parent material in a montane cloud forest in Sierra Juárez, Southern Mexico

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.     

Changes in the salt status of meadow-chestnut soils under the impact of saline groundwater in a model experiment

The continuous upward inflow and ascending capillary movement of sodium-sulfate groundwater through the profile of an initially nonsaline meadow-chestnut soil entail the displacement of exchangeable calcium by sodium in the lower Bca and BCca horizons; therefore, the content of sodium in the SEC increases to 60% and more. No unfavorable changes in the physical properties of the soils are observed because of the high salt concentration. Dissolved calcium is partially precipitated as calcite and gypsum in the Bca and BCca horizons and partially migrates, together with Cl^? ions, to the upper horizons with the ascending solution flow. In the Al horizon, Ca and Mg chlorides are accumulated as poorly crystallized strongly hydrated compounds, which give no peaks in X-ray diffraction patterns, and gypsum is deposited.     

Soil evolution over the Quaternary period in a semiarid climate (Segre river terraces,northeast Spain)

A macro- and micromorphologic study was done on the soils from a stepped sequence of seven dated fluvial terraces in the lower Segre river valley (Lleida, northeast Spain) under a present-day semiarid Mediterranean climate. The soils have evolved from the Holocene through the early Pleistocene, providing an excellent morphostratigraphic framework for evaluating time-dependent factors influencing soil formation in a dry and calcareous environment. Throughout the chronosequence, some properties are regularly age-related specially carbonatation in subsurface horizons. The carbonates occur mainly as micrite, and although microsparite and sparite also appear in the oldest soils, they are replaced by fine-grained calcite by dissolution–reprecipitation processes (micritization process), which is active at present. Some pedological paleofeatures as the presence of sparite and recarbonated argillans in oldest terrace can be interpreted as the reflex of climatic changes during the Quaternary. In spite of this climate variability, the soils display progressive and systematic patterns of carbonate accumulation: on the lowest terraces, the soils do not yet have secondary carbonates but in the beginning Late Pleistocene calcic horizons, with carbonate pendents, are developed; these pendents increase its thickness with age although pendent growth rates decreases from Late Pleistocene to Middle Pleistocene. In the middle of the Late Pleistocene, calcic horizons evolved to petrocalcic horizons, which increase its thickness in the Middle and specially in Early Pleistocene. The presence of calcic and petrocalcic horizons is the primary basis for soil classification. This criterion is applicable not only to the soils of the lower Segre river basin, but also to many soils throughout the semiarid Mediterranean region.     

The influence of topography on the development of Alfisols on calcareous clayey till in Denmark

A detailed macro- and micro-morphological study of seven closely-adjacent soil profiles on calcareous clay tills in a long-established beech wood in central Denmark, shows that depth of decalcification, thickness of textural B horizon, development of umbric epipedons and development of albic sub-horizons are all related to slope inclination, slope form and to relative situation in the slope complex.The soils may be classified within four subgroups of Alfisols, while one is a Mollisol. The MAST of 8°C poses problems of typification at suborder level between frigid and mesic classes.Development of clay skins and of glaebules and concretions as indicators of the redeposition of mobilised components, are present to greater extent in stable slope situations; with least lateral subsoil water movement. Development of albic horizons is related to greater lateral water movement.Development of cutanic features by argilluviation - argillans - do not exclude features formed by redeposition of carbonates - calcitans. Soil plasmic fabrics with both features are termed calcisepic fabrics and prove deposition of clay and carbonates in the same soil horizons, usually the lower B and C(g) horizons.Morphologically the dark epipedons show intense humification and many fecal pellets because of the undisturbed and high plant productivity and intense biotic activity. The micromorphology is one of isotic argillasepic plasmic fabrics. The argillic horizons are dominantly insepic or vosepic, while the calcareous C horizons are either argillasepic, or calci-vosepic or calcisepic. It is possible that some of the carbonate reprecipitation post-dates the argilluviation, the carbonates derived during secondary dissolution in the suprajacent horizons.     

Transformation of carbonate pedofeatures in paleosols buried under kurgans in the North Caucasus region

Carbonate concentrations in a chronosequence of paleosols buried under kurgans in the North Caucasus region at the end of the 4th century and the first half of the 5th century AD have been studied with the use of a set of morphological and isotopic methods. It is demonstrated that morphologically different phases of calcite—the collomorphic phase and the crystalline phase—in carbonate pedofeatures (calcareous pseudomycelium) and in the calcareous horizon have different elemental compositions and different isotopic compositions of carbon. Hence, these forms of calcite should have different origins. An addition of colloidal carbonates migrating in colloidal solutions from the lower soil horizons to the surface horizons during the periods of climatic aridization to the acicular calcite may be responsible for a sharp and irregular increase in the radiocarbon age of the newly formed carbonate pseudomycelium.     

Evolution of the carbonate state of agrogenically transformed dark gray forest soils in the central forest-steppe

The integrated study of the carbonate state of soils, which involves all the forms of soil carbonates at different levels of the soil organization, allows exactly assessing the degree and the rate of the soil transformation due to agricultural development. The evolution of the carbonate state in agrogenically transformed soils was assessed on a site with a known land-use history and with remaining natural soils. The direction, rate, and stages of the carbonate state transformation upon the agrogenic use of dark gray forest soils were determined on the basis of the morphogenetic analysis. Agricultural development entails a significant reorganization of the carbonate profile: a dark gray forest soil evolves into a medium-thick slightly podzolic chernozem with a greater pool of carbonates. The calcareous pedofeatures and horizons evolve stepwise: in the soil of a 100-year-old plowland, the transition to another organization of the carbonate state is observed: carbonates migrate more actively, and the dissolution-precipitation conditions are most dynamic. In the upper calcareous horizons, the structure of the calcitic pedofeatures becomes more collomorphic, and this mass fills almost all the voids; in the lower calcareous horizons, calcite is predominantly segregated into calcareous pedofeatures.     

A concept of Gleyization and its role in the pedogenesis

Three simple factors ‐ excessive moistening, anaerobic microflora and organic matter, are indispensable and sufficient conditions for gley formation. This process is always characterised by a non‐silicate iron loss from the soil fine earth or soil plasma. Gley formation takes place under conditions of stagnant or stagnant‐percolative water regimes.

In the second case gley formation induces a drastic acidification of the mineral soil part, lessivage, removal of iron, aluminium, calcium, magnesium, bleaching of the soil fine earth, and it appears the features of soil with eluvial, acid, bleached horizons. Therefore soils with such horizons should be regarded as manifestations of gley formation in conditions stagnant ‐percolative water regime on acid, neutral or leached parent material. Under influence of stagnant water regimes Fe of mineral substrat is removed and unconsiderable eluviation of Ca and Mg takes place. pH of parent material does not change or has the trend to increase. In this case does not arise a soil with bleached horizons.     

Roles of iron and clay in Genesis of acid soils under a humid,temperate climate

The occurence of acid brown soils, podzols and podzolic soils, and the intermediate types of ochreous brown and brown podzolic soils over arenaceous granite in Vosges was closely correlated with the contents of iron rather than with calcium plus magnesium in the parent materials. Acid brown soils were associated with high and podzols and podzolic soils with low contents of iron, the limiting value being near 5 percent. Additional investigations in beech forests of soils derived from a variety of acid rocks indicated that contents of iron and clay in the parent materials controlled the type of humification of litter. With higher contents of iron and clay, humification gave rise to mull. With lower contents, mor or moder was formed. The nature of humification was believed responsible for tilting pedogenesis toward brunification or toward podzolization. In brunification, the clay-iron-humus complexes that are formed tend to be immobile and promote formation of crumbly structure. The “active iron” occurs as films around clay particles and thus links them to humus. In podzolization, on the other hand, the complexes formed are of humus with iron or aluminum but without clay. These are mobile and are translocated downward in profiles to form spodic horizons. The organo-metal complexes in ochreous brown and brown podzolic soils are mobile to only a limited extent. The combined results of these investigations demonstrate that contents of iron and clay rather than calcium in parent materials determine the pathway of pedogenesis from acid rocks under humid, temperate climates.     

Use of Chromameter‐Measured Color Parameters in Estimating Color‐Related Soil Variables

Abstract

Soil color is a soil property that may be used as an interpreting index in estimating processes and properties. Quantifying color allows one to obtain information for rapidly estimating the related processes in soils. CIELAB color parameters L*, a*, and b* of ground (air‐dried and sieved) soil samples and aggregate surfaces of four soil profiles formed in calcareous colluviums in northern Turkey were analyzed. Values of color parameters measured in ground and intact soils were compared and related to soil properties by the regression technique. Results revealed that the L* value obtained with a ground soil sample was a significant predictor of organic matter in A horizons (p < 0.001). Although calcic horizons yielded the highest L* values, no significant relationship was obtained between calcium carbonate contents and lightness of soils in any of horizons studied. The parameters of b* could adequately be used to quantify dithionite‐extractable iron oxide contents in soils studied. The results further showed that the CIELAB color parameters obtained with ground samples were more informative than that of aggrevated samples in relating color parameters to soil properties.     

Distribution et localisation du Zn et du Pb dans un sol complexe situe a l'aplomb d'un gossan en milieu carbonate (Famenne belge)

Within the study area, a sulphide mineralization consisting of marcasite, sphalerite and accessory galena, as well as its subsurface oxidation product, a gossan in which the dominant mineral is goethite, are intricately intermixed with a gangue of calcite. The open profile at the mineralized site shows the succession of two soils: a leached brown soil (Hapludalf) developed in the loessic cover is underlain by a paleosol of the terra fusca type. The presence within the terra fusca of limonitic gravels indicates its genetic relationship with the underlying gossan. This is further confirmed by the distribution of Fe, Pb, Zn and Mn within the different horizons of the profile. The high values of Pb, and Zn, which are found both in the limonitic gravels and in the major B horizon of the terra fusca contrast strongly with the low values for the soil developed in loess.The different particle-size fractions from the major B horizons of both the leached brown soil and the terra fusca have been submitted to a selective dissolution method using five reagents sequentially (ammonium acetate, hydroxylamine, ammonium oxalate in darkness, ammonium oxalate under ultra violet (U.V.) radiation, strong acids). The crystalline iron oxides (which are dissolved by ammonium oxalate under U.V.) are concentrated in the sand fractions of the terra fusca and their extraction is accompanied by that of Zn. In the same particle-size fraction, hydroxylamine dissolves selectively Mn oxides and also extracts the major part of the Pb. A similar behaviour is observed when the same extraction sequence is applied to a limonitic gravel. The best evidence for the underlying mineralization is therefore found in the coarse and very coarse fractions of the terra fusca where the disintegration products of the gossan are concentrated. These products are absent in the loess covering the terra fusca.     

Upper Permian paleosols developed from limestone in the middle reaches of the Volga River: Morphology and genesis

The results of the study of paleosols preserved in the Upper Permian deposits in the central part of the Russian plate are presented. The paleosol profiles consist of the medium loamy dark brown BMg,ca horizon and the hard cemented calcareous Mm,ca and Mca horizons. The imprints of plant roots in the Mm,ca horizon and in the upper part of the Mca horizon serve as a vivid diagnostic feature of these paleosols. Two paleosol morphotypes are distinguished according to the development of the structural-metamorphic BMg,ca horizon and the micromorphological features. These paleosols were developed from highly calcareous lacustrine deposits that were initially loose and then subjected to cementation. The processes of leaching and redistribution of carbonates, as well as the development of the soil structure, vertic properties, eluvialgley processes, lessivage, and soil creep, can be identified in the studied paleosols. They bear the record of the geomorphic conditions on a flat plain with recurrently drying inland water reservoirs in a semiarid paleoclimate with well-pronounced seasons.     

The base saturation in acidified Swiss forest soils on calcareous and noncalcareous parent material. A pH–base saturation anomaly

Long‐term soil acidification leads to lower pH values and to a concomitant decrease in base saturation (BS). The relationship between pH and base saturation (BS) in acidified forest soils can be disturbed by processes such as nutrient cycling by vegetation, temporary saturation by ground water that comes into contact with calcareous material, or by upward diffusion of base cations from deeper horizons. This paper examines the relationship between pH and BS in Swiss forest soils developed from calcareous and noncalcareous parent material and identifies some of the factors that can affect the BS in the decalcified parts of soils derived from calcareous parent material. The decalcified zone in the latter soils has a higher BS on average compared to soils from noncalcareous parent material, but their pH values are identical. In the pH range 4.0–4.5, the difference in BS may vary by a factor of three. The mean BS in the decalcified zone tends to decrease with increasing depth of the calcareous layer. The water regime also affects the BS in soils on calcareous parent material. In soils temporarily saturated by groundwater (gleysols), the BS in the decalcified zone is always high (85%–100%) because of the continuous contact between the soil water and the calcareous parent material. In addition, the inhibited drainage impedes the depletion of base cations in these soils. In contrast, soils that are temporarily saturated by rainwater are depleted in base cations due to the alternating wetting‐and‐drying regime and the associated leaching of dissolved ions. In such soils, the depletion of base cations is strongly related to the extent of hydromorphy. Stagnogleyic soils, with the longest period of water saturation, have the highest depletion levels. We conclude that in such soils, the diffusion of base cations from deeper zones is strongly compensated by leaching from the very acidic soil horizons. The pH–base saturation anomaly has consequences for some of the methods used to calculate the critical loads of acidity for forest soils in Switzerland, with many soils being less sensitive than previously reported.     

Zur pedochemie des berylliums — untersuchungen einer bodengesellschaft im gebiet des bärhaldegranits (südschwarzwald)

The profile distribution of Be is given for a toposequence of podzols, brown earths, stagnogley, forest bog and “Ockererde” (slope gley with infiltrated Al, Mn and Fe). Analysed were the parent rock, fine earth, four fractions of mineral soil (fine skeleton, sand, silt, clay) and the needles of spruce trees.Beryllium is involved in selective weathering processes of elements. Accordingly, the Be-content increases from the fine skeleton to sand, rock, silt and clay, progressively. Through pedogenetic enrichment, Be accumulates in the mica-rich silt fraction.Uptake of Be by spruce is very low even from these acid soils. The accumulation in the needles becomes greater with increasing age.The pedochemical behaviour of Be is very similar to that of Al.Be is incorporated very little in the organic matter cycle, and is therefore not enriched in the soil humus.The brown earth has lost Be, especially in the A_h-horizon.In the A_e-horizon of the podzol, loss of Be is even greater; the loss is partly offset by Be-enrichment in the B-horizon.In the profiles of depressions, the Be-content is high and is ascribed to lateral flow from the slopes. Be-enrichment is especially high in horizons with a pH of about 5.The Be-balance of the watershed indicates an export of about 10% of the original amount.     

SW—Soil and Water: Improvement of Whitish Oasis Soil, Part 1: Field Experiments with a Four-stage Subsoil Mixing Plough

A prototype four-stage subsoil mixing plough was designed in Japan and built in China for the improvement of whitish oasis soil. The machine was transported to two places in China for field tests where the whitish oasis soil is found. This paper presents the trash mixing rate into mixed layer of Bca and C horizons, the inverting rate of the Bca and C horizons and the draught of the plough in the whitish oasis soil.The results show that the rolling resistance of the tracked vehicle (T802), on which the plough was mounted, was about 8 kN and the draught of the first plough body which tilled the Ap horizon was about 4 kN with a working depth of 200 mm and a working width of 500 mm. The draught of the second plough body, which tilled the surface of the Ap horizon, was about 2 kN with a working depth of 50 mm. The draught of the third plough body increased steeply with greater working depths. The draughts were about 8, 14 and 24 kN, respectively, for working depths of 117, 239 and 300 mm. The draught of the fourth plough body also increased steeply with greater working depth. The draughts were about 7, 14 and 18 kN, respectively, for working depths of 117, 178 and 239 mm. When the whitish oasis soil was disturbed by the plough bodies, it was observed that the whitish oasis soil was very hard but comparatively brittle and easily broken up. This property explains the smaller draught requirements in the whitish oasis soil despite a greater soil strength. The values of the soil-inverting rate ranged between 0·45 and 0·6, and the average value was 0·5. Perfect inversion of the Bca and C horizons was not possible, but good mixing was achieved by the plough. The average trash mixing rate in Inner Mongolia was 0·85, and that in North of River was 0·95. These data show that even in Inner Mongolia where the trash material is long, a fairly uniform trash mixing was possible.     

Thermoluminescence dating of soils developed in Late Devensian loess at Pegwell Bay, Kent

Thermoluminescence (TL) measurements on the present organic surface soil and two buried soils in loess and colluvium derived from loess at Pegwell Bay, Kent, suggest that the signal is almost completely zeroed during soil development, mainly by optical bleaching. The technique may therefore be used to date buried soils developed in loess and possibly other terrestrial sediments. Decalcification, gleying and other soil-forming processes may also affect the TL signal of the soil parent material, and seem to be the main reasons why the Btg horizons of the Early Holocene buried soil at Pegwell Bay give more recent TL dates than the parent calcareous loess.     

Sedimentological study of aeolian soil parent materials in the Río Sauce Grande basin, Buenos Aires province, Argentina

Sedimentological characteristics of aeolian soil parent materials in the Río Sauce Grande basin, southern Buenos Aires province, were analysed using grain-size distributions, transport mechanisms, dynamics of the sedimentary process and the nature of calcareous layers. Samples were collected from C horizon of 13 profiles distributed over all the piedmont areas and plains. Calcium carbonate in these materials is either inherited from the parent material or was redistributed by pedogenic processes. Their amounts in Ck horizons increase from the upper to the lower basin, and are inversely related to the thickness of soil parent material, to mean annual rainfall and to the calcrete depth.The cumulative grain-size plots show that the sediments were transported by both aeolian saltation and aeolian suspension. Most of them have coarser and more heterogeneous grain size distributions than typical loess of the northern hemisphere, indicating a larger and more fluctuating wind energy than is required for the formation of typical loess. Deposits in the upper and middle basins were deposited in two main aeolian episodes which can be related to the dry periods of the Late Pleistocene and the Late Holocene recorded in southern Buenos Aires province. In some thin profiles of the middle and lower basins, the large clay content of the calcic C horizon was probably inherited from one or more previous pedogenic events. There is a systematic increase of particle size towards the lower basin, which may be related to an increase of energy towards the lower basin or to the influence of littoral dune fields along much of the Atlantic coastal zone.     

新疆典型草原土壤腐殖酸组分的变化规律

以新疆典型草原黑钙土、栗钙土和棕漠土为对象,研究了3种土壤不同土层腐殖质矿物复合体组分及其垂直分布规律。结果表明:13种典型草原土壤腐殖质总碳量的顺序为黑钙土(35、46g/kg)、栗钙土(31.30g/kg)和棕漠土(0.68g/kg);23种草原土壤都是以胡敏素(HM)含量最高,黑钙土、栗钙土和棕漠土的含量分别为68.17%、65.47%和42.81%;3按照腐殖酸类型分析,黑钙土和栗钙土是以胡敏酸(HA)为主的富啡酸(FA)-胡敏酸(HA)型,CH/CF＞1;而棕漠土则相反,是胡敏酸-富啡酸型,CH/CF＜1;4黑钙土、栗钙土和棕漠土腐殖质组分中游离R₂O₃结合的胡敏酸分别为6.85%、5.65%和1.65%,而富啡酸分别为0.53%、0.84%和4.91%;5在3种草原土壤中,游离腐殖酸从0~20cm到40~60cm的垂直变化规律分别为:黑钙土中游离胡敏酸和富啡酸分别从5.74和2.33g/kg降到2.70和0.89g/kg;栗钙土中游离胡敏酸和富啡酸分别从1.88和1.03g/kg降到0.59和0.75g/kg;棕漠土中游离胡敏酸和富啡酸分别由2.10和2.90g/kg降到1.92和0.67g/kg。