bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subsurface Water Movement in an Upland Coastal Plain Soil as Influenced by Plinthite
Authors: Blume L. J. , Perkins H. F. , Hubbard R. K. 
Published: July 2010

AbstractWater movement in a Tifton loamy sand (Plinthic Paleudult) was monitored using bromide as a tracer for 86 weeks under natural rainfall conditions following treatment in late summer. Potassium bromide (KBr) was placed at depths between 10 and 43 cm and 60 and 102 cm in a soil having a 4.4% slope. Bromide content of water from piezometers at distances up to 60 m downslope was determined at 2‐ to 4‐week intervals during periods of perched water starting 22 weeks after the injection date. Determinations were then made for a 65‐week period. Soil samples taken at depths to 4.72 m 1 yr after treatment were analyzed for bromide content. A perched or secondary water table occurred during periods of high rainfall and low evapotranspiration. Data indicate that subsurface flow downslope occurred primarily above and within the plinthic horizon during periods when a perched water table was present. Data from soil samples collected 1 yr after KBr treatment indicate that bromide moved slowly through the plinthic layer, was interceted by subsurface layers of high density, and was retained in the watershed until removed by lateral flow.
Soil Genesis Associated with Periglacial Ice Wedge Casts, Southcentral Wyoming
Authors: Munn L. C. 
Published: July 2010

AbstractThe development of ice and sand wedges (nonsorted polygon features) in Wyoming's high basins during the late‐Pleistocene glaciation allows determination of soil development on pre‐Wisconsin and late‐Wisconsin surfaces on the same landform. Pre‐Wisconsin soils on an old alluvial terrace in the Great Divide Basin (later hosts to ice wedges) exhibited clay translocation and accumulation followed by a period during which carbonate accumulated. Soils developed in the noncalcareous fill‐materials of the ice‐wedge casts show B horizon accumulation of clay and carbonate. The late‐Wisconsin soils developed in the ice wedge casts showed clay enrichment of 13 kg m−2 and CaCO3 enrichment of 113 kg m−2. The pre‐Wisconsin soil had CaCO3 enrichment of 250 kg m−2. Parent material stratification prevented determination of absolute clay enrichment in the host soil but its clay maximum is 33% compared to 15% in the late‐Wisconsin soil. The Bt horizons in the pre‐Wisconsin soils are also much thicker. Profile morphology indicates that the present semi‐arid environment probably developed immediately as the climate warmed at the end of the Wisconsin. Clay mica and kaolinite have become enriched in surface horizons and smectite in C horizons of both wedge and wedge‐host soils.
Sphericity and Roundness of Sand in Coastal Plain Soils and Relationships with Soil Physical Properties
Authors: Vepraskas M. J. , Cassel D. K. 
Published: July 2010

AbstractSand grain roundness and sphericity were evaluated for 50 soil samples from Atlantic Coastal Plain soils to determine relationships of sand grain roundness and sphericity to the soils' cone index (mechanical impedance), bulk density, and the dense soil angle of repose. A previous investigation collected undisturbed cores from 50 tillage‐induced pans in the Atlantic Coastal Plain, and determined cone index, bulk density, and the dense soil angle of repose. One hundred sand grains were isolated from each of the 50 soil materials. Roundness was determined for each grain by comparing the grain's projected image to standard images in published roundness charts. Sphericity was also determined for the 100 grains per soil by measuring selected grain axes. Mean values for roundness and sphericity were determined for each soil sample. Mean roundness values ranged from 0.44 to 0.57 across sites, but 74% of the sites had mean roundness values between 0.45 and 0.49 inclusive. Mean sphericity values ranged from 0.74 to 0.81, but 72% of the sites had mean sphericities between 0.78 and 0.81 inclusive. Correlation coefficients for relations of cone index, bulk density, and dense soil angle of repose to roundness and sphericity were generally ≤0.26 and not significant (0.10 level). Sphericity and roundness were not significant variables in regression models describing variations in cone index and the dense soil angle of repose. Roundness was not a significant variable in regression models describing variations in bulk density among sites, but sphericity was a significant variable in models that were based on particle size characteristics alone.
A Simple Method for the Estimation of Calcium and Magnesium Carbonates in Soils
Authors: El Mahi Y. E. , Ibrahim I. S. , Abdel Magid H. M. , Eltilib A. M. A. 
Published: July 2010

AbstractA simple titrimetric method is described for the estimation of Ca and Mg carbonates in soils. It involves the determination of acid‐soluble Ca and Mg of the carbonate phase after the removal of soluble and exchangeable cations by ammonium acetate (NH4OAc). Twenty‐six tropical soils, which contain free carbonate, were used in this study. The results obtained by the proposed method were compared with those obtained by acid neutralization, calcimeter, and titrimetric methods. Analysis of variance revealed no significant difference between the percent CaCO3 equivalent obtained by the four methods when the acid neutralization method was corrected against proton adsorption. However, the proposed method has the advantage of estimating Ca and Mg carbonates. The proposed method requires no special equipment and is less time‐consuming if it follows the routine determination of exchangeable cations or the cation exchange capacity (CEC).
The Influence of Organic Complexing Agents on Iron Mobility in a Simulated Rhizosphere
Authors: Erich M. S. , Duxbury J. M. , Bouldin D. R. , Cary E. 
Published: July 2010

AbstractThe effect of complexing agents on Fe mobility was investigated using a simulated root‐soil system that consisted of 0.24‐mm o.d. cellulose fibers embedded in a clay‐agar matrix. Complexing agents diffused into the clay‐agar matrix from a solution flowing through the fibers and their effect on Fe flux to the fiber surface was determined by following Fe concentration in the effluent solution from the fibers. Experiments with the chelating agents ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), ethylenediamine di‐(o‐hydroxyphenylacetic acid) (EDDHA), and ethylene glycol‐bis‐(2‐amino‐ethylether) tetraacetic acid (EGTA) demonstrated that solubilization of Fe qualitatively followed patterns predicted from known thermodynamic stability constant‐pH relationships. The concentration of Fe in the fibers 24 h after introduction of either EDTA, DTPA, or EDDHA was increased from close to 0 to 30 to 100 g Fe L−1, whereas EGTA had no measurable effect on Fe solubility. The measured fluxes of Fe were compared with calculations based on diffusion and reaction. An equilibrium model, where the complexing agent was assumed to equilibrate instantaneously with the soil (reaction rate constant Kr = 1), predicted concentrations of Fe 103 times greater than those observed. A first‐order kinetic model, which was solved by numerical methods, gave results similar to those found experimentally when Kr was on the order of 10−7. The partial success of the thermodynamic stability constant approach was reconciled with the kinetic model by considering Kr to combine both kinetic and equilibrium factors.
Relating the Fertility Capability Classification System to Tobacco Response to Potassium Fertilization
Authors: Denton H. P. , Peedin G. F. , Hawks S. N. , Buol S. W. 
Published: July 2010

AbstractThe Fertility Capability Classification (FCC) system is a technical soil classification system developed to evaluate soil properties affecting crop response to fertilization and to aid in making fertilizer recommendations. It was developed primarily for use in lesser developed countries. Results from a series of experiments involving application of K to flue‐cured tobacco (Nicotiana tabacum L.) in North Carolina were used to determine the usefulness of the FCC system for predicting crop response to fertilization in the southeastern USA. Six rates of K, ranging from 0 to 224 kg ha−1, were applied to flue‐cured tobacco at 13 locations for 3 yr. Tobacco leaf yield response to K differed significantly among FCC soil groups. Optimum rates by soil group varied from 0 to 112 kg ha−1, compared with 84 kg ha−1 across all soils. The highest optimum rates occurred on soils with sand or loamy sand surfaces >0.5 m thick, whereas the lowest rates were on soils with loamy surfaces. Extractable soil K level in the Ap horizon (soil test K) was not related to response to K, either overall or within FCC groups. The FCC system was useful in evaluating tobacco leaf yield response to fertilization. It appears that the FCC system could be used to improve fertilizer recommendations.
Soybean Response to Available Potassium in Three Silt Loam Soils
Authors: Grove J. H. , Thom W. O. , Murdock L. W. , Herbek J. H. 
Published: July 2010

AbstractThe range in soil environments has likely contributed to variation in the determination of that level of K availability at which no further yield increase to K is expected. Potassium response of soybean [Glycine max (L.) Merr.] from three different soil environments was studied in the field to determine if a single index of K availability could be found. Relationships between grain yield, R1‐R2 leaf K concentration, ammonium acetate exchangeable K, Ca, Mg, and water soluble K, Ca, and Mg were determined. Significant (P ⩽ 0.05) yield responses to added K were found at all three sites, as were increases in R1‐R2 leaf K. Water soluble K, K/Mg, and K/(Ca + Mg)1/2 were more stongly related to plant response than extractable K, K/Mg, or K/(K + Ca + Mg). All soils provided optimal K nutrition to soybeans at soil test levels ≤100 mg K kg−1 soil, as determined by neutral, molar ammonium acetate solution. Determinations of soil solution phase composition may improve our understanding of the role(s) of soil properties on divergent patterns of response to K nutrition.
Correspondence of Soil Properties and Classification Units with Sagebrush Communities in Southeastern Oregon: I. Comparisons between Mono‐taxa Soil‐vegetation Units
Authors: Lentz R. D. , Simonson G. H. 
Published: July 2010

AbstractA preliminary second‐order soil survey (1:15840) of Squaw Butte Range Exp. Stn., Oregon, identified a single shallow upland soil that supported six contrasting sagebrush communities. Six delineations of this soil, each associated with different vegetation, were sampled intensively to objectively determine if soil properties and classification differed between delineations. Plant communities represented six different sagebrush (Artemisia) habitat types: A. longiloba/Agropyron spicatum, A. longiloba/(fescue) Festuca idahoensis, A. arbuscula/F. idahoensis, A. tridentata ssp. wyomingensis/A. spicatum, (F. idahoensis), and A. t. ssp. vaseyana/F. idahoensis‐A. spicatum. Morphological properties of profile samples were statistically compared by defining aggregate horizons (tiers) that were common to all profiles. Stepwise discriminant analysis selected elevation, aspect, presence of E and BA horizons, clay content of the Bt horizon, and sand content of surface strata as those which best distinguished between plant communities. Evidence suggests that series separations are justified based on family and class distinctions of higher categories or differences in range of soil properties, including variations in horizonation, volumetric rock fragment content of A and Bt horizons, and structure of BAt horizons. Phase separation criteria suggested include aspect, parent material, slope, and surface texture. Structure type of subhorizons, subhorizon position, and nutrient content are soil properties that may also provide important discrimination between soils possessing different range potentials.
Calculation of Soil Color from Reflectance Spectra
Authors: Fernandez R. N. , Schulze D. G. 
Published: July 2010

AbstractProcedures were developed for obtaining visible spectra of dry and moist soil powders on a Cary 17D spectrometer. Accuracy and precision were checked by measuring the colors of: (i) 28 chips of the Inter‐Society Color Council‐National Bureau of Standards (ISCC‐NBS) Centroid Color Chart, (ii) 279 chips of the Munsell Soil Color Chart, and (iii) 12 selected soil samples. Measured Munsell values were not significantly different from nominal values. Measured hue and chroma were significantly different from nominal hue and chroma, but the difference was approximately 0.25 units of chroma and, thus, is relatively small. Average deviations for duplicate measurements of Munsell hue, value, and chroma of 12 silt loam and silty clay loam soil samples were <0.1 unit of hue, value, or chroma and maximum deviations were <0.2 units. Precision was similar for both dry and moist samples. Increased accuracy and precision make it possible to quantify small differences in soil color that are difficult to quantify using only visual color matching.
Nitrogen and Potassium Fertilization Effects on Yield and Quality of Burley Tobacco
Authors: Evanylo G. K. , Sims J. L. 
Published: July 2010

AbstractField studies were conducted in 1983 and 1984 at Lexington, KY to examine the effects of N and K fertilizer on yield and chemical quality of burley tobacco (Nicotiana tabacum L. cv. Ky 14). Treatments included: NH4NO3 at rates of 112, 280, and 448 kg N ha−1; and two sources (K2SO4 and KCl), each at rates of 0, 112, 224, and 448 kg K ha−1. The following agronomic and chemical characteristics were examined: yield, price, leaf N, P, K, Ca, Mg, Cl, Mo, total alkaloid, and solanesol concentrations. Cured leaf yield, price, and solanesol concentration were strongly influenced by N × K interactions. Each was raised by increasing N rates when no K was applied; however, at higher K levels, increasing N rates resulted in smaller price increases, no yield changes, and reductions in solanesol concentrations. Reductions in cured leaf Mo concentration relative to N, K, and Mg levels with increasing K fertilization beyond 0 kg ha−1 were exaggerated as N rates were raised. No effect of N rates on total alkaloids or solanesol concentrations were noted while increased K rates increased concentrations of both. Greater cured leaf yields and Mo concentrations were achieved with KCl than with K2SO4. The positive effect of KCl on Mo concentration at low N application rates was reduced by increased N fertilization suggesting that Mo uptake was enhanced by Cl‐ but reversed at high levels of NO‐3 application.
Interrill Soil Erosion Processes: I. Effect of Surface Sealing on Infiltration, Runoff, and Soil Splash Detachment
Authors: Bradford J. M. , Ferris J. E. , Remley P. A. 
Published: July 2010

AbstractSoil erosion from interrill areas is a function primarily of soil detachment by raindrop impact and transport capacity of thin sheet flow. Soil detachment normally is the rate‐determining process and is controlled, to a large extent, by surface sealing and crusting. The purpose of this study was to measure the effect of surface sealing on infiltration, runoff, and soil loss for 20 soils ranging in texture from sand to clay. Wash and splash erosion were measured for near‐saturated soils in 0.14‐m2 Al pans exposed to laboratory simulated rainfall with an intensity of about 63 mm/h for 1 h. For most soils, wash and splash amounts decreased with time due to surface sealing with the decrease in wash being much less than the decrease in splash. Comparing the 20 soils, surface sealing caused a reduction in infiltration rate ranging from 1.2 to 36.0 mm/h and an increase in shear strength ranging from 2.6 to 42.3 kPa, resulting in a decrease in total soil loss ranging from 13.3 to 56.8 g/5 min. Total soil loss, splash, and wash were highly intercorrelated (p < 0.001).
Impacts of Acid Atmospheric Deposition on Woodland Soils in the Netherlands: I. Calculation of Hydrologic and Chemical Budgets
Authors: van Grinsven J. J. M. , van Breemen N. , Mulder J. 
Published: July 2010

AbstractTo study effects of acidic atmospheric deposition on woodland soils in the Netherlands, chemical budgets were determined from simulated water fluxes and measured soil solution concentrations. Solute concentrations were determined in soil solutions that were sampled monthly over a 3‐yr period at various depths in four different soils. Soil‐water fluxes were calculated with the SWATRE model. Rainfall and canopy troughfall were measured at the study site. Potential evapotranspiration was estimated by an adapted Penman method. Hydraulic conductivity was calculated from the soil‐water retentivity curves according to the Van Genuchten method. Simulated pressure heads could be fitted to field observations after reduction of conductivities by a factor between 6 and 60. Coefficients of variation for chemical budgets were determined by sensitivity analysis of the simulated soil‐water flux, and by measuring spatial, temporal, and analytical variability of the solute concentrations. Coefficients of variation of solute fluxes for Al and NO3 ranged from 10 to 30% between the 10‐ and 90‐cm depth, with spatial variability as the most important source of uncertainty. Coefficients of variation of chemical budgets (difference between inputs and outputs of solutes) for soil compartments that include the soil surface were also 10 to 30%, whereas those for deeper soil layers were larger, ranging from 40 to 200%.
Rate of Phosphorus and Potassium Buildup/Decline with Fertilization for Corn and Wheat on Nebraska Mollisols
Authors: McCallister D. L. , Shapiro C. A. , Raun W. R. , Anderson F. N. , Rehm G. W. , Engelstad O. P. , Russelle M. P. , Olson R. A. 
Published: July 2010

AbstractA 12‐yr study was conducted on four Mollisols in Nebraska to evaluate response of corn (Zea mays L.) and wheat (Triticum aestivum L.) to P and K fertilizers and to determine the rate of buildup or decline of these nutrients in soil. Rates of P were 0, 11, 22, and 33 kg ha−1 applied annually or in less frequent applications of higher rates in order to maintain the same average seasonal amount, along with 27 and 54 kg annual K rates ha−1 in association with 22 kg P. The P and K fertilizers were broadcast and incorporated before planting with an appropriate blanket N treatment for the two crops. Positive yield response to applied P resulted when soil test P by Bray and Kurtz no. 1 procedure was below 15 mg kg−1 for corn and 22 mg kg−1 for wheat. No positive yield response to applied K was measured in these soils of high exchangeable K but rather a yield depression was observed at the high K rate. No significant differences in yield existed between annual applications of P and the heavier less frequent applications. Soil test P level was maintained by annual P rates of 4 to 13 kg ha−1 on the eastern soils, with none applied in the west, and was more than doubled on all soils at the end of the experimental period with 33 kg applied. Three of the soils evidenced distinct increases in soil test K without K application; the fourth a slight decline. Results from P fractionations of the test soils are reported to aid in interpreting the yield results.
Clay Mineralogy as Related to Morphology of Florida Soils with Sandy Epipedons
Authors: Harris W. G. , Carlisle V. W. , Chesser S. L. 
Published: July 2010

AbstractThe clay mineralogy of Coastal Plain soils with sandy epipedons was studied with respect to taxonomic class, horizon, and the presence or absence of sand grain coatings. Relative estimates of claysized minerals were based on x‐ray diffraction peak height ratios after calibration with standards and normalization. Clay mineralogy of sandy horizons was related to whether the clay occurred as grain coatings or as loosely adhering floccules. Clays from coated (⩾5% silt + clay) and slightly coated (<5% silt + clay) sands were consistently high in hydroxy‐interlayered minerals (HIM), and usually contained gibbsite. Clays from floccules in the matrix of stripped (coating‐free) sands contained large amounts of quartz, variable smectite, little or no HIM, and no gibbsite. Mineralogical differences between clays associated with stripped sands vs. coated/slightly coated sands were highly significant statistically. Clay mineralogy of coated/slightly coated sandy horizons was similar regardless of taxonomic class or horizon depth. The A and E (stripped) horizons of Haplaquods were similar to stripped Quartzipsamment horizons in being depleted in HIM relative to other phyllosilicates. Haplaquod Bh and E′ horizons (coated to some degree) were relatively high in HIM and therefore were mineralogically similar to coated/ slightly coated Quartzipsamment horizons and to Arenic and Grossarenic Paleudult epipedons. Clay fractions from chemically reduced loamy horizons of Paleudults and Haplaquods were depleted in HIM relative to overlying coated sandy horizons. Results suggest that pedogenic processes that promote the destabilization of grain coatings (i.e., podzolization, chemical reduction) also promote the loss or redistribution of HIM associated with these coatings.
Application of the Convection‐Dispersion Model to Solute Transport in Finite Soil Columns
Authors: Barry D. A. , Sposito Garrison 
Published: July 2010

AbstractThe one‐dimensional convection‐dispersion model is investigated with respect to the proper boundary conditions to impose in applications to tracer movement in freely draining soil columns. It is shown that the model can be interpreted probabilistically and that this interpretation leads to physical restrictions on solute molecule transport through the inlet and exit boundaries of a soil column. These constraints, in turn, show that the correct exit boundary condition for a freely draining soil column is zero resident concentration or, equivalently, zero gradient in the flux concentration. This boundary constraint is combined with conditions appropriate to either an open or a closed inlet boundary to derive a variety of mass‐conserving solutions (some apparently new) to the convection‐dispersion model for both resident and flux concentrations. In particular, a new solution is presented for the resident concentration under a closed inlet boundary. The corresponding flux concentration solution for a constant solute flux at the inlet is shown to be the same as a solution first obtained by R.W. Cleary and D.D. Adrian (1973).
Ion and Sulfate‐Isotope Ratios in Arid Soils Subject to Wind Erosion in the Southwestern USA
Authors: Schlesinger William H. , Peterjohn William T. 
Published: July 2010

AbstractOur objective was to evaluate the potential for arid‐land soil dusts to contribute significantly to the content of SO2‐4 and other ions in precipitation. Soil samples collected at 102 locations throughout southwestern USA deserts were extracted with distilled water and analyzed for major ionic constituents and the stable isotope ratios (34S/32S) in soluble sulfate. Most samples were dominated by Ca2+ and HCO‐3, and were undersaturated with respect to gypsum. Only a weak correlation was found between Ca2+ and SO2‐4 in samples from upland sites. Median δ 34S of soil SO4 was +6.2‰ compared to +3.9‰ reported for precipitation. However, the median ratios for Ca/SO4 (12.00) and Mg/SO4 (1.84) in soil extracts were much larger than the same ratios in precipitation, suggesting that wind erosion of undisturbed desert soils is not a major source of the SO4 in precipitation. Calcite aerosols from desert soils may act to neutralize acid rain in the western USA.