bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extractable Iron in Relation to Soil Age on Terraces Along the Truckee River, Nevada
Authors: Alexander Earl B. 
Published: July 2010

AbstractWeathering and soil phenomena often serve as aids for correlating Quaternary deposits. An investigation was designed to determine if the ratio of acid oxalate to citrate‐dithionite extractable Fe, called the Fe ratio, has a definite age trend which might be helpful in deciding the age sequence of associated but noncontiguous Quaternary deposits. Iron was extracted from the subsoils of well‐drained Xerolls on eight adjacent terrace levels in a subhumid climate on the eastern side of the Sierra Nevada Mountains. Citrate‐dithionite treatment extracted 1.0 to 1.6% Fe from the less than 2‐mm fractions of the soils. The data suggest that the Fe ratio increases in the first several thousands of years of soil development, to 0.37 on the second terrace above the Truckee River, and then it decreases to a practically constant 0.18 in a few hundreds of thousands of years. Although the Fe ratio values are not sufficiently unequivocal to be used alone for placing associated Quaternary deposits in sequence, they may be useful supplements to other criteria.
Estimating Soil Erosion from the Redistribution of Fallout 137Cs
Authors: Ritchie Jerry C. , Spraberry James A. , McHenry J. Roger 
Published: July 2010

AbstractThe movement of fallout 137Cs from soils in three north Mississippi watersheds was found to be logarithmically (r = 0.89) related to potential soil loss as calculated by the Universal Soil Loss Equation. Analysis of other published data on 137Cs as well as the north Mississippi data also showed a significant (r = 0.95) logarithmic relation existing between soil loss and 137Cs loss from soils. This study indicates that it may be possible to calculate soil loss from the movement of fallout 137Cs in watersheds. Also it may be possible to calculate the movement of surface adsorbed nutrients like 137Cs in watersheds from soil erosion data.
Sampling Macro‐Organic Matter Profiles in Salt Marsh Plant Root Zones
Authors: Gallagher John L. 
Published: July 2010

AbstractA device for sampling the root zones of marsh plants and a method for processing the resulting cores are described. Using these techniques, five stands of marsh plants were sampled and their macro‐organic matter profiles compared. The least total macro‐organic matter was found in the high vigor Spartina alterniflora Loisel. and the Distichlis spicata (L.) Greene root zones. Within S. alterniflora stands, the macro‐organic matter in the soil profile increased as vigor of the aerial portions decreased. Juncus roemerianus Scheele and short form S. alterniflora profiles were similar in shape and had the highest macroorganic matter content.
A Steady‐State Model of Isotopic Fractionation Accompanying Nitrogen Transformations in Soil
Authors: Shearer G. , Duffy J. , Kohl D. H. , Commoner B. 
Published: July 2010

AbstractA steady‐state mathematical model of isotopic fractionation accompanying certain nitrogen transformations in soils is developed. The model takes into account ammonification, nitrification, and immobilization; and predicts that the 15N/14N ratios of nitrate and ammonium ion depend in part upon the ratio of the rates of immobilization and ammonification. The ratio of the rates of immobilization to nitrification under field conditions is unlikely to be the same as under the conditions of laboratory incubation experiments. Therefore, this prediction provides a possible explanation for differences observed between the 15N/14N ratio of nitrate extracted from soil cores and that of nitrate released during laboratory incubation of the same soils.The model described is ammenable to experimental test. If verified, an expanded version of the model may be a useful aid in the study of nitrogen transformations in the field.
Genetic Implications of B Horizons in Aqualfs of Northeastern Ohio
Authors: Ritchie A. , Wilding L. P. , Hall G. F. , Stahnke C. R. 
Published: July 2010

AbstractA sequence of five Aqualfs with B horizons ranging from moderately expressed argillic horizons to moderately expressed fragipans was contrasted by physical, chemical, mineralogical, and morphological means. These soils have developed from illitic‐rich parent till deposits of Late Wisconsin‐age; they range in clay content from 25 to 47% and in carbonates from 3 to 15%. A noncarbonate clay content of 30% appears to represent a delicate boundary governing the direction of B horizon genesis in these soils. The genesis of the fragipan appears to be primarily a physical phenomenon; micromorphological and structural properties of the fragipan closely resemble those of the parent till. In contrast, volume changes and fabric rearrangement associated with argillic horizon genesis have largely obliterated traces of rock structure present in the parent till. A dual nomenclature is proposed for fragipan‐like zones which do not meet the current minimum root‐spacing criteria for fragipans. A large part of the in situ clay gain in argillic horizons, cambic horizons, and the upper portions of fragipan zones is attributed to the disintegration of shale lithorelics.
Phosphorus Retention in Coastal Plain Forest Soils: II. Significance to Forest Fertilization
Authors: Ballard R. , Pritchett W. L. 
Published: July 2010

AbstractPhosphorus retention of 42 forest soils collected from the US Southeastern Coastal Plain was found to be significantly correlated with Al and Fe extracted by soils tests for available phosphorus. Aluminum provided better indices of P retention than Fe extracted by these tests and it accounted for more than 81% of the variation in P retention in the case of the NH4OAc (pH 4.8), 0.03N NH4F + 0.025N HCl, or 0.03N NH4F + 0.1N HCl tests.Concentrations of Fe and Al in the foliage of 4‐year old slash pine (Pinus elliottii Engelm. var. ‘elliottii’) growing on these soils were significantly correlated with soil P retention. However, foliar Fe, the most closely correlated, accounted for only 26% of the variation in P retention.Retention of P from concentrated superphosphate applied at the equivalent 56 or 224 kg P/ha 4 years previously to young slash pine was measured to 20 cm depth at 10 sites, and ranged from −14 to +125%. Retention was almost independent of application rate. Extractable Al values corresponding to 50% retention of the applied P were 40, 330, 400, and 120 ppm for NH4OAc, 0.03N NH4F + 0.025N HCl, 0.03N NH4F + 0.1N HCl, and 0.05N HCl + 0.025N H2SO4 extractions, respectively. It is proposed that in the interest of maintaining long‐term growth responses and minimizing possible pollution effects, these values be used for delineating soils of low P retention where less soluble sources of P, such as rock phosphate, should be used if P fertilization is required.
Seedling Growth of Sorghum in Clay‐Sand Mixtures at Various Compactions and Water Contents
Authors: Hemsath Delroy L. , Mazurak Andrew P. 
Published: July 2010

AbstractMixtures of kaolinite clay and fine sand fraction from Tripp subsoil (Typic Haplustoll) were prepared with 1.0, 3.8, 7.5, 15, and 30% clay. The clay‐sand mixtures were compacted into cylinders at bulk densities of 1.00, 1.25, 1.50, and 1.75 g · cm‐3. The cores were then subjected to matric suctions of 0.15, 0.33, 1.7, and 8.6 bars.Penetrometer resistance of the cores increased from 0.25 to 68 kg · cm‐2 as the bulk density of clay‐sand mixture increased from 1.00 to 1.75 g·cm‐3. Matric suction of the clay‐sand mixture contributed much to the increased penetrometer resistance with a correlation coefficient of 0.57.The elongation of sorghum [Sorghum bicolor (L.) Moench] roots in the cores increased as the clay content increased from 1.0 to 7.5% at all bulk densities when the matric suction was <1.7 bar. Further increase in the clay content decreased the root elongation. The largest negative correlation coefficient (r = −0.65) between root elongation and variables studied was with matric suction. It was considered to be the major factor affecting root length. Penetrometer resistance of clay‐sand mixture was critical in relating soil physical conditions to root growth. At a penetrometer resistance of 20 kg·cm‐2 or greater, no root growth in the clay‐sand mixtures was observed.
The Effect of Overburden Pressure on Chloride and Water Movement in Swelling Clay Soil
Authors: Kissel D. E. , Ritchie J. T. 
Published: July 2010

AbstractThis study was conducted to evaluate the influence of overburden pressure on the movement of water and Cl‐ through short undisturbed cores of swelling clay soil. When overburden pressure was removed from the cores, saturated flow rates increased. Subsequent miscible displacement studies revealed that the percent soil water excluding Cl‐ was also reduced. When soil cores were loaded with overburden pressure, the amount of soil water excluding Cl‐ was approximately 50%. When overburden pressure was removed, the amount of soil water excluding Cl‐ was 33%, about the same value as measured in disturbed soil cores of approximately the same water content. Differences in the quantity of soil water excluding Cl‐ between loaded and unloaded cores were due to an interaction between soil structure and the negative charge on the clay in the loaded cores. Apparently, when overburden pressure was removed, smaller pores increased in diameter, which allowed Cl‐ to diffuse more freely into these spaces.
The Solubility Product of Gibbsite at 15°, 25°, and 35°C
Authors: Singh S. Shah 
Published: July 2010

AbstractThe solubility product of gibbsite was found to be 10‐34.45, 10‐33.96, and 10‐33.52 at temperatures of 15, 25, and 35C, respectively. The findings are consistent with the data of others at 25C. A general equation is given for the calculation of Ksp of gibbsite at different temperatures. The heat of reaction of synthetic gibbsite in the temperature range of 15 to 35C was 18,944 calories/mole.
Soil Mottling and Drainage in a Mollic Hapludalf as Related to Suitability for Septic Tank Construction
Authors: Vepraskas M. J. , Baker F. G. , Bouma J. 
Published: July 2010

AbstractThe feasibility of septic tank construction in a fine silty Mollic Hapludalf, with a mottled subsoil overlying permanently unsaturated sand, was investigated by measuring K values and soil drainage rates in situ. Mottles with chromas of 2 inside peds in the silty clay loam subsoil indicated reducing conditions and channel and plane neoferrans indicated oxidative conditions in the larger pores. Physical data showed high K values and drainage rates at saturation, due to channels and planes, but a very strong drop of these values upon desaturation. Lack of extended saturation of the entire subsoil makes possible excavation of the silt cap and construction of a septic tank seepage bed in the underlying sand.
Response of Soybeans to Liming as Related to Soil Acidity, Al and Mn Toxicities, and P in Some Oxisols of Brazil
Authors: Martini J. A. , Kochhann R. A. , Siqueira O. J. , Borkert C. M. 
Published: July 2010

AbstractThe response of soybeans (Glycine max (L.) Merrill) to the direct and residual effect of liming in relation to soil acidity, Al and Mn toxicities and P availability was studied in five Oxisols of Southern Brazil under successive wheat (Triticum aestivum L.)‐soybean cropping. Yield responses to liming were highly significant due to the high exchangeable Al and extractable Mn, the low pH, exchangeable Ca + Mg, and available P found in these soils. Optimum yields were obtained when liming adjusted Al from 0.1 to 0.5 meq/100g (1.5% Al saturation), soil pH from 5.2 to 5.7 and Ca + Mg from 5.7 to 8.5 meq/100g. Liming also increased root nodulation and reduced P fixation and Mn levels in the soil.
Parent Material of Upper‐ and Middle‐Coastal‐Plain Soils in North Carolina
Authors: Gamble E. E. , Daniels R. B. 
Published: July 2010

AbstractIn the upper‐ and middle‐Coastal Plain of North Carolina, Paleudults are on the old landscapes; Hapludults, with low base status, are on the young valley side slopes. This distribution of soils suggests a parent‐material control of soil development. X‐ray and petrographic analyses of samples of the surficial sediments showed kaolinite to be the dominant clay mineral below the solum and quartz to be the primary sandsized mineral. Weatherable minerals such as feldspar are rare. The effective exchange capacity of the clay is less than 15 meq/100 g. Aluminum is the predominant cation, and the pH ranges from 4.2 to 4.8. The percent base saturation by the sum of cations is < 35% both within and below the solum. The surficial sediment is most clayey at the surface and gradually becomes coarser with depth. The Paleudults are thus developed in the most clayey part of the sedimentary unit. These facts suggest the parent material was composed primarily of quartz sand and kaolinitic clay, with a low pH and with aluminum the dominant exchangeable cation. As a consequence only Ultisols developed; the original character of the parent material has strongly influenced such things as the mineralogy, base saturation, and vertical clay distribution.
Crop Tree Thinning Increases Availability of Soil Water to Small Yellow Birch Poles
Authors: Hannah Peter R. 
Published: July 2010

AbstractMeasurements of soil‐moisture depletion with a neutron probe on five forest sites supporting yellow birch poles (Betula alleghaniensis Britton) in Vermont indicate moisture is depleted at slower rates around individual trees that have had “partial release” and “full release” than around trees with “no release.” The effects of thinning on depletion are cumulative over a growing season; by late August moisture depletion curves have diverged substantially. Significant differences in depletion rates due to treatment effects occurred for 20 to 40% of the measurement intervals within a growing season. Most of the significant differences are judged to occur because of oddities in the data. Measures of net soil depletion rate are extremely variable because of microsite differences. Apparent depletion rates and theoretical depletion patterns for short intervals are examined. Moisture depletion rates between soil depth classes (0–15 cm, 15–46 cm, 46–76 cm) are significantly different during most intervals within a growing season. The data obtained in this study portray only general trends, and it is questionable whether more intensive studies of this nature should be planned to obtain significant differences in results.
Unsaturated Hydraulic Conductivity from Cumulative Inflow Data
Authors: Ahuja L. R. 
Published: July 2010

AbstractA method of determining the wetting‐phase unsaturated hydraulic conductivity K(θ) from the data of cumulative inflow into a uniform soil core when water enters through a porous plate of high hydraulic resistance is described and evaluated. The method is based on piecewise application of the Green and Ampt (1911) approach to the above process of infiltration. The K(θ) determined by this technique from the numerical‐solution inflow data of Yolo light clay were within 20% of the K(θ) values actually used in obtaining the numerical solution in two different cases of hydraulic resistance. Similar analysis of the experimental inflow data of Salkum silty clay loam for four different hydraulic resistances yielded the K(θ) data which closely agreed with the K(θ) values determined by detailed analysis of the soil‐water content transients.
Evaluation of Simulated Seedling Emergence through Rainfall Induced Soil Crusts
Authors: Holder C. B. , Brown K. W. 
Published: July 2010

AbstractExtensive areas of cultivated soil throughout the world develop rainfall‐induced crusts which impede seedling emergence. Quantitative information is needed on the factors influencing the development of crusts and on the influence of ameliorating treatments on crust strength. A convenient method was developed to make impedance measurements. Soil was placed in boxes which were equipped with guided tubes to allow a probe (simulated seedling) to penetrate the soil crust from below. Measurements were made by means of a balance which supported the probe, as it was raised by means of a jack.The equipment was used to collect data on the relationship between rainfall intensity and soil crust impedance. Simulated rainfall of intensities from 1.3 to 5.1 cm/hour and durations of 19 to 60 min were used to form the crusts. Determinations of crust impedance were made daily for 7 days with a 12‐hour drying cycle.For the loam soil tested, the maximum daily average impedances were 1,766, 2,226 and 1,851 g of force for rainfall intensities of 1.3, 2.5, and 5.1 cm/hour respectively. Crust impedance for all tests increased initially as the soil dried, then declined as cracking increased.An inverse relation was found between mechanical impedance and the percent crust moisture between 20 and 2.8% moisture; the maximum impedance occurred in the narrow range of 2.8 to 2.2% moisture. An increase in the coefficient of variability as the soil dried was associated with cracking. Different durations of rainfall at similar intensities resulted in larger differences in impedance than did different intensities for the same duration.
Rhizosphere pH as Influenced by Plants, Soils, and Nitrogen Fertilizers
Authors: Smiley R. W. 
Published: July 2010

AbstractThe rhizosphere pH (pHr) of field and container‐grown wheat plants was measured and compared to the nonrhizosphere soil pH (pHb). The predominant form of N supplied to the roots was a major factor influencing the pHr. The pHr was generally lower than pHb where NH4 was supplied, higher where NO3 was used, and relatively unchanged where both forms were added. Differences in pHr of up to 2.2 units were recorded for NH4‐ vs NO3‐fed wheat plants (Triticum aestivum L.) in pots. Differences of up to 1.2 units occurred in the field. The pHb and pHr also differed by as much as 1.2 units. Changes in pHr were correlated with the concentrations of NH4 in potted soils, although the acidifying influence of NH4 decreased with time, as nitrification proceeded. Reductions in pHr values persisted longer in NH4 treated, fumigated soils, and in non‐fumigated soils where NH4 fertilizers had been treated with a nitrification suppressant. The pHr differences in NH4‐ vs NO3‐N treated soils were reduced by organic amendments. Difference with respect to pHr were found among wheat varieties and plant genera. The ability of plants to alter the pHr was related to assimilation of NO3 primarily in the roots (monocots) or shoots (dicots).
Soil‐Landscape Relationships in a Closed Drainage System
Authors: Malo D. D. , Worcester B. K. , Cassel D. K. , Matzdorf K. D. 
Published: July 2010

AbstractGeomorphic and geometric conditions of a small, closed drainage system on the glacial drift plain of North Dakota were related to measured properties of the soil along a linear transect. Multiple regression techniques were used to define relationships statistically between soil properties and quantitative morphometric parameters. Landscape position and soil properties were significantly related. The geomorphic processes of erosion and sedimentation were evident in the measured properties of the soil. Textural variations encountered in profiles can be attributed to erosional and sedimentational activity present on the hillslope rather than pedologic activity. The degree with which the geologic processes of erosion and sedimentation affect the soil and their properties depends on landscape position.
Kinetic and Equilibrium Studies of Boron Desorption from Soil
Authors: Griffin R. A. , Burau R. G. 
Published: July 2010

AbstractKinetics of boron desorption from soil were determined using 0.05M mannitol solutions to create pseudo first‐order reaction conditions. The results showed two separate pseudo first‐order reactions and one very slow reaction for which detailed kinetic treatment was not attempted. The relative amount of boron associated with the two fast reactions was independent of soil texture and of initial sample boron content.It was postulated that the two reaction rates were due to desorption from two independent boron retention sites. It was speculated that the two fast reactions were due to desorption from hydroxy iron, magnesium, and aluminum materials in the clay fraction. The third or slowest reaction rate was probably due to diffusion of boron from the interior of clay minerals to solution phase.Equilibrium studies showed that boron desorption followed a 2‐site analog of a linear form of the 1‐site Langmuir expression. Langmuir adsorption maximum values for each site corroborated those calculated from the kinetic study and supported the multisite interpretation of the kinetic data.
The Occurrence of Aluminum‐Phosphate Precipitate in Plant Roots
Authors: McCormick Larry H. , Borden F. Yates 
Published: July 2010

AbstractThe occurrence of an Al‐PO4 interaction in plant roots has been described by many investigators as being an adsorption‐precipitation reaction which probably occurs along the root surface and in the cell wall region near the root tip. The present investigation was designed to observe and to identify more precisely the sites of this Al‐PO4 interaction in plant roots. Molybdenum, which has a sufficient atomic weight to be electron dense, was selected as a stain because prior investigations had shown that molybdenum becomes strongly attached to prepared precipitates of Al‐PO4. Electron micrographs gave strong inferential evidence that an Al‐PO4 precipitate did occur in the plant roots as scattered globules in the mucilaginous layer along the root surface and in the intercellular regions of the root tip.
Growth of Atriplex canescens (Pursh) Nutt. Improved by Formation of Vesicular‐Arbuscular Mycorrhizae
Authors: Williams S. E. , Wollum A. G. , Aldon Earl F. 
Published: July 2010

AbstractFourwing saltbush [Atriplex canescens (Pursh) Nutt.] roots were stained for detection of endomycorrhizal fungi by simmering in an acid fuchsin‐chloral hydrate solution. Naturally occurring endomycorrhizal fungi were observed in symbiotic association with the roots.Mycorrhizal fourwing saltbush grown in nonsterile soil had a greater dry weight and accumulated more phosphorus than nonmycorrhizal plants grown in sterile soil. Inoculation of fourwing saltbush with a known endomycorrhizal fungi, Endogone mosseae Nicol. and Gerd. tended to stimulate the plants to greater growth than uninoculated plants.
Distribution of Nonionic Surfactant in Soil Columns Following Application and Leaching
Authors: Miller W. W. , Letey J. 
Published: July 2010

AbstractThe distribution of 14C‐tagged surfactant (Soil Penetrant) was observed in soil columns following application of various concentrations and leaching under unsaturated flow on wettable (Pachappa) and water‐repellent (Morris Dam) soils. The maximum depth of surfactant penetration for a given leaching period was greater for Pachappa than for Morris Dam. Following leaching there was a more uniform distribution of surfactant throughout the column of Pachappa soil. Water drop penetration time (WDPT) experiments showed good correlation between experimental distribution as determined by 14C tracing and actual reduction of water repellency to a given depth. Consequently, the movement and distribution characteristics of a non‐14C‐tagged surfactant (Aqua Gro) on the Morris Dam soil following application and leaching was qualitatively examined by the WDPT method. A theoretical model was tested for its ability to qualitatively predict experimental Soil Penetrant distributions. There was reasonable agreement between experimental and calculated distributions. Specific adsorptive characteristics at low equilibrium concentrations were found to be very important to surfactant distribution in a given soil.