Representative Soil Profiles Research Articles

Physical properties of soils contaminated by oil lakes, Kuwait

Abstract In preparation for a marine assault by the coalition forces, the Iraqi Army heavily mined Kuwait's coastal zone and the oil fields. Over a million of mines were placed on the Kuwait soil. Burning of 732 oil wells in the State of Kuwait due to the Iraqi invasion caused damages which had direct and indirect effect on the environment. A total of 20–22 million barrels of spilled crude oil were collected in natural desert depressions and drainage network which formed more than 300 oil lakes. The total area covered with oil reached 49 km2. More than 375 trenches revealed the existence of hard, massive caliche (CaCO3) subsoil which prevent leached oil from reaching deeper horizons, and limited the maximum depth of penetration to 1.75 m. Total volume of soil contaminated reached 22,652,500 m3 is still causing environmental problems and needs an urgent cleaning and rehabilitation. Kuwait Oil Company has recovered approximately 21 million barrels from the oil lakes since the liberation of Kuwait. In our examined representative soil profiles the oil penetration was not deeper than 45 cm. Infiltration rate, soil permeability, grain size distribution, aggregates formation and water holding capacity were assessed.

Factors controlling the emanation of radon and thoron in soils of the eastern U.S.A.

Emanation coefficients (proportion of generated Rn atoms that escape from a solid material) have been measured for 222Rn ( t 1 2 3.8 days) and 220Rn (thoron, t 1 2 , 55 s) on 68 disaggregated soil samples from 12 soil profiles representative of the eastern U.S.A. Average values for sites are 0.20 for 222Rn and 0.16 for 220Rn. Based on distribution of 226Ra among the exchangeable, organic, Fe-oxide, sand, silt and clay fractions of the soils, a multiple regression indicates that the organic-exchangeable fraction, occurring mainly as coatings on grains, has an emanation coefficient for 222Rn of 0.46, and the silt-clay fraction has an emanation coefficient of 0.22. The latter value is verified by experiments. The organic component makes the largest single contribution to Rn in soil gas. Mineral grains have twice the 222Rn emanation as 220Rn, implying that about half the Rn atoms are emanated directly to pore space, and the remainder are freed by track-etching and diffusion over a period of days. Emanation for 220Rn appears to be dominated by Fe-oxides, the main host for pedogenic 232Th. Surface A- and E-horizons have low emanation coefficients for {Su220}Rn, probably because of a lack of Fe-oxides in these horizons.

Soil-water behaviour in a push terminal moraine: comparison of one- and two-dimensional simulations based on intensive regional field observations

To predict the contamination risk of drinking water in a water catchment, regionalization methods, in which regional transferability is presupposed by assigning areas of same qualities, are used. Those methods use soil information at the field scale to build up soil profiles, which serve as input for one-dimensional simulation models of water and solute transport together with management data. These simulation models compute groundwater recharge to determine the transport and contamination risk of solutes. The regionalization method assumes horizontal homogeniety and one representative soil profile (principal profile) for each soil mapping unit. Our objective is to show that those regionalization methods have to be improved in regions of high spatial variability of soil qualities. As an example we examine a terminal moraine typical of northern Germany. We combine intensive investigations of the soil structure, long-time field observations and simulation results to show the necessity to improve methods for soil mapping. Our results suggest that it is necessary to perform higher-dimensional simulations of water and solute transport in regions of high spatial soil structure variability. Two-dimensional simulations compute earlier and higher groundwater recharge rates than one-dimensional simulations.

Pedogenesis by clay dissolution on acid, low-grade metamorphic rocks under mediterranean forests in southern Tuscany (Italy)

Pedogenesis on acid, low-grade metamorphic rocks under well-developed forests was studied in the meso-mediterranean climatic zone. To that purpose three representative soil profiles on phyllite and sandstone under sclerophyllous oak, pine and heathland were selected. The major soil forming processes consisted of transformation of part of the K-mica (muscovite) to (hydroxy-interlayered) vermiculite and smectite, impoverishment both in major elements (Al, K, Mg and Fe) and fine particles, and redistribution of sesquioxides as organic complexes. These processes indicate clay hydrolysis under acid conditions and subsequent removal of solutes by lateral subsurface flow. The resulting impoverishment of the soil profiles could be mainly attributed to hydrolysis under acid conditions brought about by slow decomposition of organic matter. The proposed mode of pedogenesis deviates strongly from the current concept of fersiallitisation, and is probably restricted to acid parent materials in mediterranean climates where lateral removal of soluble weathering products is ensured throughout the largest part of the year.

Properties and erosional response of soils in a degraded ecosystem in Crete (Greece)

To study desertification processes relating to soil erosion, a climatological and altitudinal gradient from south to north was selected in Crete (Greece) and four locations were selected along the gradient. At the locations precipitation ranged from 1400 mm/year at the highest location to 400 mm/year at the lowest. All locations are affected by the actual land use: intensive grazing, small controlled fires, and abandoned agricultural terraces. Representative soil profiles were described in the field and analyzed in the laboratory, and rainfall simulation experiments in the field measured soil erosion over different soil surfaces and land uses. Data on physical and chemical properties were obtained from the soil profiles and soil hydrology, and erosion data were obtained from the rainfall simulation experiments. Soil aggregation was studied with samples taken from the soil in the rainfall simulation plots and special attention being paid to the aggregate size distribution and the water-stable microaggregation. The interaction between climatological conditions and land use seems to be the main factor controlling soil erosion. This paper describes how the expected erosion along the gradient (from the most humid to the driest site) can be affected and disturbed by specific processes derived from land use.

Evaluating soil maps for prediction of soil water properties

SummaryConventional soil survey stratifies a region into mapping classes and characterizes each by a representative soil profile within it. The efficacy of the procedure for predicting particle‐size fractions, bulk density, water retention, and available water capacity (AWC) of the soil at previously unvisited sites on the Plain of Languedoc in southern France is evaluated for three scales of survey (1/10 000, 1/25 000 and 1/100 000) and is compared to that of prediction from stratified random and simple random samples. Data from 85 soil profiles on a random transect were used for evaluation.Classification partitioned the variation of the measured properties, except for AWC, well at the 1/10 000 and 1/25 000 scales, whereas classification at the 1/100 000 scale was less effective. At the 1/10 000 and 1/25 000 scales both classification and stratified random sampling were better for prediction than simple random sampling for the same total sample. On average the representative profiles proved substantially better predictors than the stratified random samples, but in most situations where soil stratification performed well efficiencies of the two predictors were similar. In essence, the more successful the classification was the more difficult it was to improve prediction by selecting representatives instead of sampling randomly within classes. These results confirmed statistically that the soil surveyor can exercise intuition and judgement to classify and select representatives.

Soil formation on limestones in the arid region of Northeast-Somalia

In order to clarify the history of landscape in the arid part of northern Somalia, the genesis of soils in the Darror Valley and its surroundings has been investigated. More than 70 soil profiles were described in the field and 20 soil profiles were analysed in the laboratory. In this paper analytical results of 5 representative soil profiles and 6 limestone samples are presented. Four soils are developed from limestone and are situated on levelled plateaus whereas the fifth soil is developed from alluvial material in a shallow depression. The alteration intensity of these soils have been estimated by means of the Fe o content and the Si l:Al l-ratio. In soils of the elevated areas both the Fe o content and the Si l:Al l-ratio decreases with depth. In soils developed on alluvial material the Fe o content as well as the Si:Al-ratio show no variation with depth and their values are as high as those for the top soils of the elevated areas. This reflects that the parent materials of the soils in the depressions are originated from weathered material of limestones and that the soils are very weakly altered in situ. By balancing the carbonate amount in the soils of the elevated area, the primary height of their parent rocks (= limestone) was calculated. The age of the soils was also calculated through determination of the amount of carbonate lost by weathering. These calculations were based on the assumption that the amount as well as the fluctuation of rain during soil formation was similar to the present conditions. The results of these calculations indicate that the oldest soil in the landscape is relatively young, and that most soils developed since the late Pleistocene, as a result of a continuous soil erosion since Tertiary, caused by tectonic uplift of the landscape and/or intensive rainfall, which occurred during past nonarid climatic conditions.

Evaluation of some soils in South‐Western Nigeria for arable crop production

Abstract Five representative soil profiles were excavated and examined along a toposequence at different physiographic points in Itagunmodi area of Southwestern Nigeria. The soil series identified were Ibule, Ijare, Owena, Itagunmodi, and Adio. The soils were characterized with physical, chemical, and mineralogical analyses. Ibule series was not suitable for yam and cassava production. Ijare series was marginally suitable for yam, maize, lowland rice, and cassava production. Owena and Itagunmodi series were highly suitable for yam, maize, and cassava production. However, the latter two series were moderately suitable for lowland rice. Adio series was only suitable for lowland rice production.

Sand mineralogy and related properties of some soils in South‐Western Nigeria

Five representative soil profiles were excavated along a toposequence selected in the Itagunmodi area of South‐Western Nigeria. The soils were subjected to physical, chemical, and mineralogical ana...

Particle size and free iron oxide distribution in some tropical soils derived from amphibolite

The patterns of distribution of particle size and free Fep3 (Na-dithionite-extractable (Fe(d) and NH.-oxalate-extractable (Fe(o) were studied in five representative soil profiles in south-western Nigeria. The soils were found to vary from slightly acid to strongly acid. Organic carbon decreased with increasing depth. The pattern of distribution of free Fe,03 was related to that of clay in two of the soil profiles (Ibule and Adio series). However, in the other three soil profiles (Ijare, Owena and Itagunmodi series), free Fep3 distribution was not related to clay. Silt content did not show any definite pattern of distribution. The content of free Fep3 had reached advanced stage of crystallinity or aging in the soils because of the low Fe(o)/Fe(d) ratios in the soil profiles.

Statistical equations for estimating field capacity, wilting point and available water capacity of soils from their saturation percentage

SummaryStatistical equations were derived for estimating three soil moisture constants, i.e. field capacity (FC), wilting point (WP) and available water capacity (AWC), from soil saturation percentage (SP), which is an easily determinable parameter. The regression equations were evaluated from a data set obtained on 438 soil samples collected from different horizons of 111 profiles of the Indogangetic Plains in northern India, having a wide variation of texture and other physico-chemical properties. The three soil moisture constants were positively correlated with logarithms of SP (r = 0·985 for FC v. In SP, 0·979 for WP v. In SP, and 0·914 for AWC v. In SP). The regression equations were thetested on an independent set of experimental data on 57 samples collected from 14 representative soil profiles of the study area. Values of the three moisture constants of this data set, predicted from the regression equations, were in exceptionally good agreement with the observed values. The mean estimation error (the error of the estimated value relative to the measured value) was only 0·55% for FC, 0·12% for WP and 0·67% for AWC.

Podzolized soils on hilly and steep land near Tennyson Inlet, Marlborough Sounds, New Zealand: classification and relation to landform, slope and altitude : Laffen, M D; Daly, B K; Whitton, J S Aus J Soil ResV24, N2, 1986, P115–133

Eight soil profiles ranging in altitude from 30 m to 820 m at Tennyson Inlet in the Marlborough Sounds, New Zealand, are described, classified and discussed in terms of morphology, chemistry and clay mineralogy. The soils are formed from greywacke on forested hilly and steep land under a superhumid climate. Profiles show eluvial and/or illuvial features typical of podzols and podzolized soils. Within the study morphological, chemical and mineralogical properties show patterns in weathering, leaching and podzolization. Differences in weathering are related mainly to geomorphic history and topography. The most strongly weathered soils occur at altitudes below about 200 m where parent materials were probably inherited from Late Pleistocene interglacial or interstadial weathering. Less weathered soils occur at higher altitudes where parent materials were derived from widespread periglacial erosion during the last glaciation, and from periodic erosion during the Holocene. Weathering and also leaching is least on soils on very steep slopes (>38) at altitudes above 200 m, where rejuvenation by slope movement has been more active than on less steep slopes. Patterns in weathering are clearly shown by clay mineralogy, with strongly weathered soils dominated by kaolinite, and less weathered soils dominated by vermiculite. Differences in podzolization are attributed mainly to greater effective rainfall, leaching and accumulation of amorphous minerals and mineral-organic complexes with increasing altitude. The combination of field and laboratory data shows that at altitudes below about 200-300 m profiles are relatively weakly podzolized, while podzolized soils and podzols occur at higher altitudes. Podzolization patterns are clearly shown by subsoil values of acid-oxalate and pyrophosphate Fe and Al, NaF, pH and P retention. The profile at highest altitude is dominated by smectite clays and the greyish-coloured solum is interpreted mainly as a relatively thick (80 cm) eluvial horizon resting directly on bedrock. Neither the New Zealand Genetic Classification nor Soil Taxonomy satisfactorily classifies all the soils. Introduction The Marlborough Sounds occur in the north of South Island, New Zealand. They are a partly drowned river valley system dominated by steep hill and mountain slopes rising abruptly from sea level to altitudes exceeding 1000 m. Tennyson Inlet is one of the major southern arms on the western side of Pelorus Sound. Soil mapping in the region showed that there was a reasonably consistent altitudinal pattern of soils based largely on climate, degree of weathering of parent materials, slope angle and landform position. The altitudinal patterns show distinct trends in soil weathering, leaching and podzolization (Laffan and Daly 1986). Throughout the Marlborough Sounds podzolized soils and podzols occur widely at altitudes above 550 m, but they also occur near sea level in areas such as Tennyson Inlet with superhumid climate (Laffan 1980~). To characterize the altitudinal pattern of podzolized soils and podzols, eight representative soil profiles were selected for study at Tennyson Inlet. The soils are formed from greywacke on

Accumulation of copper, lead and arsenic in some Australian orchard soils

A survey was made of copper, lead and arsenic in 98 surface soils from orchards in South Australia and Tasmania and the distribution of these elements in six representative soil profiles was studied. Copper, lead and arsenic have accumulated in the soils due to the use of sprays. Concentrations were found which were 25-35 times greater than background values. Investigation of the profiles indicated that copper and lead have been strongly retained in the upper parts of the profiles, but arsenic can be lost. Possible mechanisms for loss of arsenic are discussed. Copper and lead extracted by DTPA and EDTA were highly correlated with 'total' concentrations determined on aqua regia digests. No relationships were evident between the concentrations of copper, lead and arsenic in former orchard soils and the concentrations in ryegrass and white clover.

Clay soils on limestone in South Limburg, The Netherlands, 1. Setting and general characteristics

Detailed soil mapping in the Ransdalerveld area pointed to the occurrence of clay soils of different ages, characteristics and genesis. Three representative soil profiles were therefore selected and studied in detail. In this first of three articles, some observations and conclusions on the distribution, age and characteristics of these soils are presented. The “old” soils, developed on the plateaus in predominantly limestone-weathering residues, are classified as Lithic Hapludalfs, whereas the “young” soils on the valley slopes are classified as Rendollic Eutrochrepts if they lack a loess cover and as Typic Hapludalfs if they have a loess cover. Weathering and soil formation are discussed in the second and third parts.

SOIL FORMATION IN NORTHEASTERN CANADA∗

ABSTRACT Morphological properties and chemical analyses of translocated elements of ten representative soil profiles along a transect from the boreal through the subarctic to the arctic zones show that the intensity of the main soil forming processes (organic matter accumulation, leaching, gleying, podzolization, and clay mineral transformations) generally decreases northward. This decrease is related to variations in the soil forming factors and the processes they control, rather than to any one soil forming factor.

Simplified procedures for estimating the fundamental period of a soil profile

abstract A study was made of simplified procedures for estimating the fundamental period, T , of a linear or equivalent linear model of a soil profile. Closed form solutions and approximate methods for computing the first period of an elastic shear-beam representation of the profile were examined. Closed form solutions are presented in chart form for the following cases: (a) shear-wave velocity increasing as a power of depth, (b) shear modulus increasing or decreasing linearly with depth, (c) two-layer profile, and (d) overconsolidated or uniform crust on layer with modulus increasing with depth. Seven approximate methods developed to estimate the period of a layered soil profile without a computer were also discussed and evaluated. For this evaluation, the periods of 76 representative soil profiles were estimated by each one of the approximate methods, and the results compared with the exact values. Methods 6 (Successive Use of Two-Layer Solution) and 7 (Simplified Version of the Rayleigh Procedure) gave errors less than 10 per cent for the period in all cases considered, and these methods are recommended for practical use. The approximate methods and the closed form solution charts may be used to estimate the characteristic site period, T s , included in the proposed (1976) modifications to the seismic provisions of the Unified Building Code.

Soil‐Geomorphic Relationships in a First‐Order Valley in Central New York

AbstractMorphologically the soils in Hemlock Creek watershed are related to geomorphic development since glaciation. Initial drift deposits covering the 75‐ha area in south‐central New York were modified by mass movement (solifluction) and then altered by fluvial aggradation‐degradation under a periglacial environment, and by erosion in more recent times. Eight soil profiles representative of the geomorphic components forming the watershed were evaluated.Fragiochrepts dominate the shoulder, backslope, and upper footslope components. They are also the major soils on congeliturbate terraces and on step‐treads of the upper basin. Fragiaquepts are common on the lower footslope and toeslope components and also occur on portions of the step‐treads of the cirque‐like basin. Fragipans have formed in both glacial till and congeliturbate deposits indicating a pedologic origin. Structural expression and density of the pans increase with a decrease in natural drainage in both deposits. Dystrochrepts are dominant soils on the summit and on the intermediate level fluvial terraces; Entisols occur on the low level alluvial terraces. Pan formation is thought to be precluded by nearness of bedrock (< 1 m) to the surface in the summit area and by matrix textures in the fluvial terraces. Stratigraphic changes that produce distinct discontinuities in fluvial terrace profiles are readily evident. Incipient stratification in congeliturbate deposits appears to affect soil morphology, especially horizon thickness, in these relatively young soils.

Sheet Pile Design with Variable Soil Parameters

A computer program was developed to assist design engineers in their calculations for a sheet pile section under given soil conditions and a given factor of safety in which the Free Earth Support Method is used. The purpose of this study was to investigate those parameters which have a significant effect on design and to determine their relative importance. Three representative soil profiles have been studied that cover many of the conditions encountered in practice, including all granular material behind and below the sheet pile, a multilayered cohesive deposit, and a granular backfill over a cohesive layer. Study results are presented and recommendations are made for further research efforts.

Properties of Some Soils of the Upper Amazon Basin of Peru

AbstractSeveral representative soil profiles of the Peruvian Amazon jungle were collected in the vicinity of Yurimaguas and Iquitos and characterized in the laboratory in order to classify them according to the US soil taxonomic system. The most extensive well‐drained soils are Typic Paleudults; the poorly‐drained ones are Typic Tropaqualfs or Tropaquepts. The Paleudults were predominantly of kaolinitic mineralogy with small quantities of 2:1 minerals present. The poorly‐drained soils were predominantly montmorillonitic or of mixed mineralogy. Where coarsetextured parent materials occur in localized areas. Tropaquods and Haplorthods are found. High base status Haplaquolls are found along the margins of the Amazon and Napo Rivers. The base status of the Paleudults is not as low as in the main soils of the South American savannas. The base status of the more poorly‐drained soils is higher. Evidence from surrounding countries suggests that these soils are very extensive in the Upper Amazon Basin of South America, outside the influence of the Brazilian and Guyana shields. These areas have been previously mapped as Oxisols or their equivalents.

Genesis of Layer Silicates in Representative Soils in a Glacial Landscape of Southeastern Wisconsin

AbstractQuantitative mineralogical analysis of the clays and silts of two representative soil profiles of a glacial landscape indicated the relative extent of depositional influence as well as the effect of mineral weathering. The more intensely leached upland Lapeer loam of about pH 5 has a clay mineralogical content of 20% mica and 12% kaolinite. Clay in the less leached, neutral Saylesville silt loam occurring on a plain at a lower topographic position contains 40% mica and 6% kaolinite, as does the calcareous till under the Lapeer solum. A direct relationship exists between the pH of the horizon and content of mica in soil clay (r = 0.97) for 13 horizons of these and related soils. Variable total sand contents of the different horizons demonstrated the variable origin of the material from which the horizons developed.About 20 cm of loess was incorporated into the Lapeer loam. The Lapeer solum and weathered Peorian loess of Illinois are similar with respect to (i) content of about 2% K2O in the clay fractions, and (ii) a coarse silt/fine silt ratio of about 0.7. The dolomitic lacustrine deposits of the C2 and C4 horizons of the Saylesville soil had a vermiculite/mica ratio in the clay of 0.18. These horizons contain no sand and have clay mineral components nearly identical to those of the sandy loam till of the Lapeer, which has a vermiculite/mica ratio of 0.19.