Free Sesquioxides Research Articles

Incipient ferralization and weathering indices along a soil chronosequence in Taiwan

The low hilly topography of Green Island, a volcanic island off southeastern Taiwan, includes an altitudinal sequence of sub‐horizontal benches. We examined eight profiles along this sequence, ranging from pale brown loamy coral sand on the lowest bench that fringes the coast at an elevation of about 10 m to deep, intensely red and acid clay on the highest bench at about 240 m. Chemical analyses, differential Fe extractions, thin sections, X‐ray diffraction of the clay minerals and indices of pedochemical weathering and strain indicated that soil development progressed by weathering of primary and secondary phyllosilicates through argilluviation in the intermediate stages to the generation of increasing quantities of free Fe. The Fe accumulates as free sesquioxides, which crystallize with age. Taxonomically the soil types progress from sandy coral Arenosol, through Eutric Cambisol, Hypereutric Lixisol and Acrisol to incipient Ferralsol (Udipsamment → Eutrudept → Udalf → Udultisol → Udox in Soil Taxonomy). The profiles are interpreted as a chronosequence, although this is complicated by minor and upwardly diminishing contributions of reef coral to the mainly igneous parent materials. There are also variations in the andesitic‐basaltic bedrock, and minor aeolian inputs in the higher and older soil types. Regional eustatic sea‐level correlations, 14C dating of carbonates on the two lowest benches and estimates of local tectonic uplift indicate that the incipient Ferralsols on the upper bench might date from about 150 ka. The transition through argilluvial Acrisols to incipient sesquioxide‐dominated Ferralsols appears, therefore, to develop within 100–200 ka on Green Island, which is faster than usual.HighlightsGreen Island (Taiwan) has been volcanically dormant but tectonically active for 2 million years. The island has a toposequence of bevelled surfaces with relatively uniform andesitic regoliths. The soils of the surfaces form a chronosequence from Arenosols through Acrisols to incipient Ferralsols. The transition from argilluvial to ferralitic pedogenesis, at 100–200 ka, is relatively rapid.

Soil boron status: impact of lime and fertilizers in an Indian long-term field experiment on a Typic Paleustalf

In Indian agriculture, nitrogen (N) and phosphorus (P) fertilizers are predominantly used by the farmers, often ignoring secondary and micronutrients. Significance of boron (B) in nutrient management studies has been increasingly underlined under intensive cropping systems particularly in acid soils. In order to understand the distribution of soil native B in different fractions and their contribution to plant B uptake as influenced by nutrient management, soil samples collected after wheat (2009–2010) from a long-term experiment (LTE) continuing since 1972–1973 on Typic Paleustalf of Ranchi were subjected to sequential fractionation of soil B. Treatments included N alone, NP, NPK, 150% of recommended NPK, NPK + farmyard manure (FYM), NPK + lime, and an unfertilized-control. Five soil B fractions were determined along with hot CaCl2-extractable (available) B. Averaged across the treatments, the soil had low organic carbon (C), pH and cation exchange capacity (CEC), and high free sesquioxides. Total B content was 21.7 mg kg−1. Among different B fractions, residual B was the major contributor to total B and other fractions collectively shared 7% of total B only. Application of N alone depleted readily soluble, specifically adsorbed and organically bound B bringing the contents even below unfertilized-control. Conjoint use of lime or FYM with NPK increased significantly these fractions, whereas a decrease in oxide bound B was noticed under these treatments. Available B was positively correlated with these fractions indicating their significance in controlling B availability in the soil. The study revealed that use of lime or FYM helped modifying the distribution of soil B in different fractions by way of changing soil pH and organic C content, resulting in enrichment of plant available pool. A drastically low available B content in different treatments receiving fertilizers alone, however, suggested the necessity of B fertilization at prescribed rates for maintaining soil B fertility as also high crop yields.

Response of Escherichia coli O157:H7 survival to pH of cultivated soils

The Escherichia coli (E. coli) O157:H7 survival dynamics in original and pH-modified agricultural soils were investigated to determinate how E. coli O157:H7 survival responded to the pH values of different soils, identify the relationships between E. coli O157:H7 survival time (t d ) and soil properties, and assess the potential pathogen contamination after soil pH changed. The six soil samples were collected from different provinces of China, and 18 pH-modified soil samples were obtained from original soils by treating the original soils with direct electric current. The E. coli O157:H7 cells were inoculated into 24 soils and incubated at soil moisture of −33 kPa and 25 °C. The soils were sampled for determining the numbers of E. coli O157:H7 at given time intervals over the incubation. The effects of soil pH change and other properties on the t d values were analyzed. The t d values in the test soils were between 7.1—24.7 days. Results indicate that soil pH, texture, and free Fe2O3 (Fed) were the most important factors impacting the t d values in the test soils. Further, the response of E. coli O157:H7 survival to pH change varied with different soils. In the acidic soils (shorter t d values), the t d values decreased as the pH decreased and Fed increased, while in the neutral or alkaline soils (pH ≥ 6.45, longer t d values), the t d values did not change significantly with pH. The changes of amorphous and free sesquioxides induced by pH change might strengthen the response of E. coli O157:H7 survival to soil pH. Closer attention should be paid to E. coli O157:H7 long survival in soils and its potential environmental contamination risk.

Possible influence of termites (Macrotermes bellicosus) on forms and composition of free sesquioxides in tropical soils

Abstract There has been less concern about soil mineralogical alteration than about soil physical, chemical and biological changes induced by termite nest-building activity. Furthermore, much less attention has been paid to free sesquioxides than to phyllosilicate minerals. In the present study, we conducted field morphological observations and selective dissolution analysis to characterize free sesquioxides in termite ( Macrotermes bellicosus ) mounds as compared with surrounding pedons in different toposequence positions, i.e., seasonally flooded valley bottom, hydromorphic fringe and well-drained upland sites. Distinctive redoximorphic features, such as surface yellowish layers on mound structures from the fringe site, indicate possible alteration of iron sesquioxide forms in the mounds due to the transportation of soil from reductive (aquic subsoil) to oxidative (epigeal mound) environments by the nest-building activity of M. bellicosus . On the other hand, the iron-soluble content in the dithionite–citrate–bicarbonate (DCB) system (Fe d ) was generally higher in the mound structures than at the adjacent sub-surface (Ap2) horizon at each toposequence position, while there was less difference in the content of acid ammonium oxalate (AAO) extractable iron (Fe o ) as compared to Fe d . As a consequence, the iron activity index (Fe d /Fe o ratio) was found for the most part to be lower in the mound structures than in the neighboring Ap2 horizon. In addition, the content of Fe d , AAO-soluble Al (Al o ) and DCB-extractable Al (Al d ) was significantly correlated with clay content in these soils. These findings suggest that M. bellicosus preferentially collects clay particles, probably from the clay-rich subsoils, such as the argillic horizon, which has been formed by the co-migration of phyllosilicate minerals and relatively crystalline sesquioxides. The species then likely incorporates them into the mounds, which induces an increase in the Fe d content relative to that of Fe o , resulting in a decreased iron activity index in the mound structures.

Clay mineralogy of a podzol developed under a Sciadopitys verticillata forest on Mt. Irazu, Shikoku mountains, Southwest Japan

A podzolic soil developed under a Sciadopitys verticillata forest on the side of Mt. Irazu in Shikoku mountains, Southwest Japan was investigated mainly by a clay-mineralogical method. The results are summarized as follows: This soil was a Haplic Podzol based on a comparison with the classification by WRB. Its parent materials consisted mainly of volcanic ash refered to as Akahoya tephra, which was confirmed by the presence of abundant bubblewall type volcanic glass. In the E horizon, smectite was dominant, and small amounts of mica- smectite interstratified minerals and kaolin minerals were also present. In the Bs and Be horizons, considerable amounts of chlorite-vermiculite intergrade and free sesquioxides were detected, and the presence of imogolite was noticed. Small amounts of kaolin minerals and allophane were also present in the B horizons. The clay mineral composition of this Podzol was almost similar to the characteristics of other Podzols and podzolic soils although small amounts of imogolite and allophane were found in the B horizons. Moreover, the influence of eolian dust on the mineral composition in this Podzol was considered based on the presence of abundant crystalline clay minerals.

Characteristics of free sesquioxides and humic acids in soil distributed under Warm-temperate forest climate in Nyu mountains, Fukui Prefecture, Central Japan

The activity and crystallinity ratios of free iron oxides, and the ΔlogK and RF values of humic acids were analyzed in five soil types in the Nyu mountains, Fukui Prefecture, to examine the relation between the zonality of soils and the bioclimatic conditions under the Warm-temperate deciduous broad-leaved forest climate. The characteristics of free iron oxides and humic acids were as follows: The Dark red soil, Kunimidake series was a Dark Red soil under the Cool-temperate deciduous broad-leaved forest climate; the Dry brown forest soil (reddish), Tega series was a Yellow-Brown Forest soil under the Warm-temperate deciduous broad-leaved forest climate; the Dry brown forest soil, Takasu-1 series and the Yellow soil, Yada series were Yellow-Brown Forest soils under the Warm-temperate lucidophyllous forest climate; and the Red soil, Oshibayama series and the lower parts of the Tega series were paleo-red soils. These results indicated that zonal soils under the Warm-temperate deciduous broad-leaved forest climate were Yellow-Brown Forest soils in the Nyu mountains, Fukui Prefecture. The Dark red soil, Kunimidake series corresponded to a Hyperdystri-Rhodic Cambisol of World Reference Base for Soil Resources, WRB (FAO, ISRIC, and ISSS: World Soil Resources Reports 84, 1998). The Dry brown forest soil (reddish), Tega series, the Dry brown forest soil, Takasu-1 series, and the Red soil, Oshibayama series were compared with the Hyperdystri-Chromic Cambisol (WRB). The Yellow soil, Yada series was a Hypereutri-Chromic Cambisol (WRB).

Surface Charge Characteristics of Alfisols and Inceptisol and the Changes on Phosphatization

Three surface soil samples (0-1.15 m) were collected from different locations of West Bengal, India, namely, Jhargram (Alfisol), Bolpur (Alfisol), and Mohitnagar (Inceptisol) having contrasting physicochemical properties. The charge characteristics of the clay fraction of these soils were probed in terms of the zero-point of charge (ZPC) of the soils. The high values of ZPC noted for the Jhargram and the Bolpur soils may be due to the presence of a large amount of free (variable-charge) sesquioxides in these soils; lower ZPC values were noted in the Mohitnagar soil. Furthermore, the negative magnitudes of ΔpH [pH (KCl) - pH (H 2 0)] values, noted for the present soils, suggested that the Mohitnagar soil had less developed characteristics, whereas the Jhargram and the Bolpur soils were in more advanced stages of pedogenic development. The soil samples studied for ZPC were also treated with aqueous KH 2 PO 4 solution, and the ZPC values of these phosphate-treated soil samples registered shifts to lower pH values. This may have arisen from an increase in negative charge on soil colloids, following ligand exchange with the added phosphate. The surface potential and the surface charge density of each soil were found to increase in negative magnitude on phosphate application, possibly due to concomitant increases of the negative charges of the clay fraction of the given soils on phosphate fixation through ligand exchange mechanism. The implication of the above parameters, especially their changes on phosphate treatment of the soils, have been related to the tendency of the given soils to immobilize the added phosphate.

Soil Catenas on pinedale and Bull Lake moraines, Willow Lake, wind river mountains, Wyoming

Soils in coarse-grained tills on Pinedale (about 20,000 years old) and Bull Lake (about 140,000 years old) moraines show significant variaton with slope position and age. Soils on the Pinedale moraine are mostly non-calcareous Typic Cryoborolls with A/Bw/C profiles that thicken considerably downslope. These soils are weakly developed due to their youth and to the unstable, steep (up to 24°), highly convexo-concave slopes. Soils on the Bull Lake moraine are mostly Argic Cryoborolls with A/Bt/C profiles. These soils are more strongly developed than soils at similar positions on the Pinedale moraine because the Bull Lake moraine is older and has less steep (up to 16°), more gently curved slopes. The soils on the Bull Lake moraine contain more clay, a higher proportion of pedogenic clay, more weathered stones, and more free sesquioxides. Erosion and dry conditions at the convex summit and shoulder sites on the Bull Lake moraine have resulted in thin soils with minimal argillic horizons; these soils are only slightly more strongly developed than soils at analogous sites on the much younger Pinedale moraine. In contrast, at the concave sites in downslope positions the soils on the Bull Lake moraine are much more strongly developed than analogous soils on the Pinedale moraine; slow deposition of weathered material, probably transported by creep, has acted concurrently with pedogenesis to form soils with thick, homogeneous argillic horizons. The relationship between hillslope curvature and soil properties on both moraines is shown by significant correlations between soil properties and the second derivative of the hillslope profile. This relationship is probably due primarily to the interaction of soil formation and soil creep.

Soil catenas on pinedale and bull lake moraines, willow lake, wind river mountains, Wyoming

Abstract Soils in coarse-grained tills on Pinedale (about 20,000 years old) and Bull Lake (about 140,000 years old) moraines show significant variaton with slope position and age. Soils on the Pinedale moraine are mostly non-calcareous Typic Cryoborolls with A/Bw/C profiles that thicken considerably downslope. These soils are weakly developed due to their youth and to the unstable, steep (up to 24°), highly convexo-concave slopes. Soils on the Bull Lake moraine are mostly Argic Cryoborolls with A/Bt/C profiles. These soils are more strongly developed than soils at similar positions on the Pinedale moraine because the Bull Lake moraine is older and has less steep (up to 16°), more gently curved slopes. The soils on the Bull Lake moraine contain more clay, a higher proportion of pedogenic clay, more weathered stones, and more free sesquioxides. Erosion and dry conditions at the convex summit and shoulder sites on the Bull Lake moraine have resulted in thin soils with minimal argillic horizons; these soils are only slightly more strongly developed than soils at analogous sites on the much younger Pinedale moraine. In contrast, at the concave sites in downslope positions the soils on the Bull Lake moraine are much more strongly developed than analogous soils on the Pinedale moraine; slow deposition of weathered material, probably transported by creep, has acted concurrently with pedogenesis to form soils with thick, homogeneous argillic horizons. The relationship between hillslope curvature and soil properties on both moraines is shown by significant correlations between soil properties and the second derivative of the hillslope profile. This relationship is probably due primarily to the interaction of soil formation and soil creep.

GENESE D’UN HORIZON PROFOND FAIBLEMENT CIMENTE DANS UN PODZOL SABLEUX DES BASSES TERRES DU QUEBEC

An Orthic Humo-Ferric Podzol formed on a sandy deposit in the St. Lawrence lowlands exhibited a weakly cemented horizon at depth. Weathering of minerals was active mainly in the upper Ae horizon and released large amounts of iron, aluminum and silica. These elements migrated down the profile as organo-metallic complexes and accumulated as concretions in the podzolic B-horizons but also in the cemented horizon at depth. Micromorphological analysis showed that this latter horizon had a chlamydic/plectic assemblage. A comparison was made with other horizons found at depth in various profiles and differing from this one by their macro- and micromorphological, physical and chemical properties. The relative content of the various constituents of the cement was calculated. The sum of organic matter plus free sesquioxides ranged from 7 to 85%. There are apparent similarities in the formation of ortstein and duric horizons. The results serve to establish the concept of "ortstein-duric horizon-fragic horizon" intergrades in weakly cemented horizons found at depth in many Quebec soils.

Mechanical composition, free sesquioxides and chemical composition of surface gleyed red and yellow soils in Okinawa

Mechanical composition, free sesquioxides and chemical composition of surface gleyed red and yellow soils in Okinawa

Studies on genesis and classification of soils in warm-temperate region of Southwest Japan

Abstract The free sesquioxides in the soil may exist both in the crystalline and amorphous forms. The amount and the relative distribution of these forms within the soil profile can have a most important bearing on the physicochemical properties of the soil, on the interpretation of soil genesis and on studies connected with Intensity and condition of weathering (1, 2).

The Influence of Organic Matter Upon Microelements Mobility in Soils

Samples from surface and subjacent horizons of main soil types from chernozem to podzol were selected. Both soil colloids and released cations may be retained or deplaced to the depth. The differences of the averages and medians and the histograms of the two horizon properties show the translocation of clay and free sesquioxides and the retention or migration of some nutrient cations. 
 The deplacement to the depth were charactherized by migration level difference of concentration in the two horizons A2-A1, by the migration index namely the concentration ratio A2/A1 and by migration gradient, the angular coefficient m of linear relation between the content of the same component in the two horizons.

TENEURS ELEVEES DE FER LIBRE ET IDENTIFICATION TAXONOMIQUE DE CERTAINS SOLS DU QUEBEC CONTENANT DE LA MAGNETITE

Free iron determined after extraction by acid ammonium oxalate was found to be abnormally high in various horizons of two Quebec soils containing magnetite, namely: an Orthic Humic Podzol (Pikauba series) and an Orthic Regosol (Malbaie series). When magnetite was removed, prior to the analysis, truer values for free amorphous sesquioxides of iron and aluminum were obtained and could serve to distinguish Podzolic from other classes of soils. The calculated pH-dependent cation exchange capacities were not affected by the presence of magnetite in soils. This last criterion, together with pH in CaCl2, exchangeable aluminum and degree of base saturation, can well serve as a substitute for differentiating Spodic B horizons from other horizons as used in the Canadian taxonomic classification of soils.

Identification of imogolite in the filmy gel materials in the imaichi and shichihonzakura purlice beds

Abstract In this paper are described the properties of filmy gel substances occurring in the Imaichi (Imaichi-tsuchi) and Shichihonzakura (formerly called Jobukanuma-tsuchi (2,5)) pumice beds. The properties of such filmy materials from the Kanuma (Kanuma-tsuchi) , Imaichi, and Kitakami pumice beds have been described by many investigators (1,8, 9, 10,12, 13, 14, 15, 19, ). KANNO et al. (9) concluded that they were a mixture of poorly crystalline montmorillonite, allophane, and free sesquioxides. However, the presence of montmorillonite as an important constituent has been disproved by MIYAUCHIA nd AOMINE (12), ho concluded that the gel films from the Kitakami and Kanuma pumice beds consist principally of imogolite.

Effect of Phosphate Carriers and Doses on Progressive Changes on the Available Phosphorus Status of Major Soil Groups of South India: Soil Incubation Study

A detailed knowledge of the pattern of fixation existing over a period of time will enable one to decide upon the type of phosphate fertilizer to be applied to bring about the minimum waste of fertilizer through fixation. Soils are known to differ considerably with reference to their capacity to fix applied soluble phosphates. Variation in soil reaction, clay minerals, lime and free sesquioxides have been demonstrated to bring about appreciable differences in the capacity of soils in the matter of fixation or availabilisation of phosphates. In Madras State a number of dissimilar groups of soils occur and detailed information regarding phosphate availability changes with time in these soils is not available. The present work was taken up to obtain such detailed information.

Phosphate retention by New Zealand soils and its relationship to free sesquioxides, organic matter, and other soil properties

Phosphate retention from KH2PO4 solution at pH 4.6 was measured in some New Zealand soil profiles, arranged in sequences of increasing weathering and leaching, from sedimentary and volcanic parent materials. P retention from KH2PO4 solution correlated closely with Pretention measured by adding solid Ca(H2PO4)2H2O to moist soil and subsequently measuring water-soluble P. P retention by topsoils correlated closely with organic carbon, total nitrogen, loss on ignition, organic phosphorus, Tamm Al and Fe, and neutral citrate-dithionite Fe. Subsoil P retention correlated closely with Tamm Al and Fe and citrate-dithionite Fe. Soil organic matter was not considered to be directly concerned in Pretention; the close correlation with P retention followed from a close correlation between soil organic matter and Tamm Al and Fe. On each parent material, Tamm Al, Fe, and P retention increased with degree of weathering to a maximum in moderately weathered soils of silt texture and then decreased in strongly weathered soils of clay texture. With increasing degree of leaching within the profile, P retention and Tamm Al and Fe decreased in topsoils and increased in subsoils. P retention per unit of Tamm Alar Fe was similar in topsoils and subsoils. Allophane in soils lowered the P retention per unit of Tamm Alar Fe. Soils with allophane contained appreciable Tamm Si (> 5 mM Si) . Possibly the Tamm Si combined with Tamm Al and Fe, thereby preventing P retention by the Al and Fe.

Allophane in Some Ando Soils

Abstract Allophane has been known to occur widely in volcanic ash soils in Japan and New Zealand. However, exact knowledge of its nature has not been well established, mainly because of extreme difficulty to separate it in pure state and of its x-amorphous nature. In the course of the studies on soil allophane, it was noticed that certain Ando soils contained two different mineral colloids together, in addition to crystalline clay minerals and free sesquioxides. X-ray examination revealed that one was x-amorphous colloid which would be called allophane, and the other an unknown colloid of low crystallinity. Imogolite*** was proposed as the name of the latter colloid by the present authors after imogo in which imogolite was first found. Imogo is a brownish yellow, volcanic ash soil. in the Kuma basin in the Kumamoto Prefecture3). When deferration treatment is applied to the soils, allophane disperses both in an acid and alkaline media, whereas imogolite disperses in an acid medium and flocculates in an alk...

STUDIES ON THE BASALTIC SOILS OF NORTHERN IRELAND

SummaryThe fine sand separates (0.02–0.2 mm.) from five basaltic soil profiles have considerable cation‐exchange capacities (C.E.C.) ranging from 16.5 to 31.4 m.e. per cent. Only a small part of the C.E.E. is due to clay minerals (diameter > 2μ) cemented into aggregates of fine‐sand dimensions by free sesquioxides.Mineralogical studies of the fractions obtained, after separation by the bromoform technique, show all heavy mineral groups (s.g. > 2.85) to have a high content of pyroxenes (principally augite) followed by the opaque minerals (mainly magnetite). The heavy groups have small C.E.C., i.e. < 7.5 m.e. per cent., as expected from the mineralogical composition.In the light fractions (s.g. < 2.85) which account for 57–80 per cent. of the total fine‐sand separates, quartz predominates in fractions from surface horizons of the profiles. In the lower horizons where quartz is less abundant, greenish‐yellow particles (pseudo‐aggregates) predominate and comprise over 45 per cent. of the light fractions. Whilst zeolites occur only in negligible amounts and feldspars do not represent more than 10 per cent. of the light fractions, yet the C.E.C. of these fractions are considerable, ranging from 41.7 to 72.4 m.e. per cent. Refractive‐index measurement and colour indicate that the pseudo‐aggregates are mainly chlorites. They must be individual particles, since prolonged reduction failed to cause any further disruption.The calculated values for the C.E.C. of the pseudo‐aggregates range from 90 to 110 m.e. per cent.; the same order of magnitude as that for vermiculite and montmorillonite.X‐ray photographs of the isolated pseudo‐aggregates from three fine sands show that the particles are of two types: (a) principally vermiculitic under good drainage conditions, (b) principally montmorillonitic where the drainage conditions are poor. Chlorites could not be detected, but there was a small amount of kaolinite and some amorphous material.It is suggested that the pseudo‐aggregates are individual particles representing an intermediate stage in the weathering of ferromagnesian rocks to the clay minerals, vermiculite or montmorillonite.The high C.E.C. of the fine sands are due to (i) a small contribution from clay minerals (diameter < 2μ) present in the fine sands as the result of aggregation and cementation by free sesquioxides, and (ii) a major contribution from the pseudo‐aggregates, which have C.E.C. between 90 and 11O m.e. per cent.

Iron and Titanium Oxides in Soil Clays and Silts

Abstract The methods of extraction of free sesquioxides in soils are discussed. Using aluminium foil and ammonium tartrate, the readily soluble sesquioxides are removed from soil profiles and the resultant mechanical analyses are compared. Differences between iron oxide content and titanium oxide content of treated and untreated silt and clay fractions, show that there is more readily soluble material in the surface horizons and this is related to the power of humus to render soluble these relatively insoluble materials. High iron oxide content and titanium oxide content of deep horizons are believed to be due to leaching of parent rock, with consequent removal of alkalis and subsequent elevation of the sesquioxide percentage. The processes of translocation of iron and titanium are discussed.