bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphorus Availability and Redistribution in Relation to Profile Development in an Illinois Landscape Segment
Authors: Smeck Neil E. , Runge E. C. A. 
Published: July 2010

AbstractMollic Albaqualfs in northwestern and west central Illinois occur sporadically in small isolated areas surrounded by Argiudolls and Haplaquolls. A transect was studied to determine (i) if Mollic Albaqualfs are phosphorus deficient relative to the associated weakly developed soils, (ii) dominant forms of phosphorus present in soils at varying stages of development, and (iii) the quantities of vertical and horizontal phosphorus movement within a landscape segment.Phosphorus availability increases as the degree of profile development increases, which implies that these Albaqualfs have a higher phosphorus‐supplying power than the associated, more productive Argiudolls and Haplaquolls. Fractionation of inorganic phosphorus reveals increasing aluminum, iron, and reductant‐soluble plus decreasing calcium phosphate on progressing toward the Albaqualf end of the transect. Total phosphorus content as well as progressive enhancement of eluvial and illuvial total phosphorus horizons also increases as pedogenetic development increases. Reconstruction of total phosphorus profiles reveals that the most strongly developed Albaqualf has accumulated 493.49 g/m2 of phosphorus whereas the most weakly developed Aquoll has lost 151.34 g/m2. The 1.1‐ha landscape segment studied has incurred a net loss of 188.7 kg of phosphorus. Phosphorus translocations, within the landscape segment studied, greatly aid in explaining the variation in available phosphorus encountered in this transect.
Soil Water Evaporation: Long‐Term Drying as Influenced by Surface Residue and Evaporation Potential
Authors: Bond J. J. , Willis W. O. 
Published: July 2010

AbstractEvaporation with time was measured from wetted columns of fine sandy loam treated with seven rates of surface residue and subjected to six different evaporation potentials (shaded and unshaded columns in each of three trials). With either shaded or unshaded columns, increasing the rate of soil water evaporation by increasing evaporation potentials or by decreasing rates of surface residue resulted in greater total soil water evaporation after 60 days drying. Surface residue influenced soil temperatures during first and third stage drying and decreased the range between maximum and minimum temperature.
A Comparison of a Large‐Seeded (NC2) and a Small‐Seeded (Starr) Peanut (Arachis hypogaea L.) Cultivar as Affected by Levels of Calcium Added to the Fruit Zone
Authors: Slack T. E. , Morrill L. G. 
Published: July 2010

AbstractSeveral greenhouse experiments were conducted to compare various Ca treatments on selected vegetative and reproductive characteristics of Starr and NC2 peanuts. Calcium and K uptake and distribution characteristics in Starr and NC2 peanut plant parts were studied also. Starr and NC2 peanuts were grown in sand cultures with separated rooting and fruiting containers for direct comparisons.Starr and NC2 peanuts were dependent upon a Ca supply in the fruit zone for proper development of fruit. Starr peanuts produced a larger weight of kernels at low Ca levels than NC2 peanuts. Starr peanuts apparently make more efficient use of Ca for kernel development than the larger seeded NC2 peanuts.
Improvemet of a Solonetzic (Slick Spot) Soil by Deep Plowing, Subsoiling, and Amendments
Authors: Rasmussen W. W. , Moore D. P. , Alban L. A. 
Published: July 2010

AbstractSoil improvement studies, including deep lowing, subsoiling and gypsum treatments, were conducted on an irrigated solonetzic soil association in southeastern Oregon. The unproductive saline‐sodic (solonetz‐like) soil tentatively classified as Malheur silt loam (with slick spots) and described as a Nadurargid, occurs in complexes with normally leached soils of the Nyssa and related soil series. The saline‐sodic soils were chemically reclaimed in 3 to 4 years by deep plowing 90‐cm deep without gypsum and by deep plowing with gypsum at rates of 18 metric tons/ha (8 tons/acre) and 36 metric tons/ha (16 tons/acre). Crop yields, water intake rates, and water and root penetration were greatly increased by deep plowing. The soils were moderately improved by 36 metric tons/ha of gypsum alone and by subsoiling with gypsum. Subsoiling without gypsum was not beneficial. The results over a 4‐year period indicate that the salt‐affected soils were effectively and most economically reclaimed by deep plowing without gypsum. Deep plowing also improved the productivity and physical conditions of the non‐saline associated soils.
Distribution of Concretions from Selected Soils of the Inner Bluegrass Region of Kentucky
Authors: Phillippe W. R. , Blevins R. L. , Barnhisel R. I. , Bailey H. H. 
Published: July 2010

AbstractTotal iron and manganese was determined on concretions and soil samples by X‐ray emission. Soils studied included Maury, Mercer, and Lawrence, which are well‐drained, moderately well‐drained and somewhat poorly‐drained, respectively. Iron‐Manganese concretions were observed in all horizons, with a maximum of 46% by weight in a Maury C horizon. The Fe/Mn ratios decreased with increasing concretion size. This decrease was largely due to increased Mn content associated with the larger size concretions. Further analyses for composition showed that quartz and clay minerals (vermiculite, montmorillonite, kaolinite, and mica) account for most of the remaining fractions. Traces of titanium and phosphorus were also found. Microscopic studies of the concretions indicated two types of internal fabric; (i) undifferentiated (structureless), and (ii) differentiated or concentric structure. Concretions from the somewhat poorly drained soils are characterized by undifferentiated fabric and diffuse external boundaries. In contrast the concretions from the well‐drained soils are usually spherical, with sharp external boundaries and differentiated fabric.
Effect of Soil Air Movement and Compressibility on Infiltration Rates
Authors: Van Phuc Le , Morel‐Seytoux H. J. 
Published: July 2010

AbstractThe purpose of the study was to determine the hydrologic significance of the soil air flow and of its compressibility in the process of infiltration and moisture redistribution. Results of a numerical solution of the equations describing the simultaneous flow of air and water in a soil are presented. The results show that the air flow and compressibility may affect significantly the infiltration rates and the saturation profiles.
Pore Size Distributions of Soils From Mercury Intrusion Porosimeter Data
Authors: Nagpal N. K. , Boersma L. , DeBacker L. W. 
Published: July 2010

AbstractSoil water characteristic curves are routinely determined by the pressure plate and pressure membrane techniques. Similar curves can be derived from pore size distribution curves obtained by the mercury intrusion porosimeter technique. Mercury is forced under pressure into previously oven‐dried and evacuated samples. The applied pressure is increased in discrete steps and the volume of pores intruded between pressure steps is obtained. Equivalent pore sizes corresponding to the applied pressures are calculated with the pressure of displacement equation. This technique allows analysis of many samples per day and has therefore an advantage over standard methods.Soil water characteristic curves of eight soils ranging in clay content from 0 to 57% were determined by the pressure plate and pressure membrane technique and compared with similar curves derived from mercury intrusion data. Results obtained by the two techniques agreed well for soils which do not shrink or swell with changes in water content, but not for samples with swelling clays.
Steady Infiltration from Buried, Surface, and Perched Point and Line Sources in Heterogeneous Soils: I. Analysis
Authors: Philip J. R. 
Published: July 2010

AbstractThe quasilinearized steady infiltration equation is generalized to apply to heterogeneous soils with conductivity depending exponentially on both moisture potential and depth. Mathematical developments, including a theorem connecting surface and buried source solutions, follow closely those established previously for homogeneous soils. Solutions are found for buried, surface, and perched point and line sources. Physically relevant solutions are limited to the following ranges of β, the dimensionless coefficient of dependence of conductivity on depth: for buried and surface sources, β ≥ 0; for perched point sources, β ≤ −1; for perched line sources, β < −1. It is of interest that the homogeneous medium (β = 0) is an extreme case for existence of buried and surface source solutions; and that perched source solutions (relevant to subirrigation) exist only for soils with conductivity increasing rapidly enough with height above the impermeable base. Detailed mapping of flows and general discussion is left to Part 2.
Synthesis of Phenols and Phenolic Polymers by Hendersonula toruloidea in Relation to Humic Acid Formation
Authors: Martin J. P. , Haider K. , Wolf D. 
Published: July 2010

AbstractHendersonula toruloidea in glucose or organic residue media produced high yields of a humic acid‐type polymer. As much as one third of the substances, including biomass synthesized by the fungus, consisted of the polymer. The primary phenolic constituents of the polymer are orcinol, 3,5‐dihydroxybenzoic acid, and probably 2,3,5‐trihydroxytoluene with smaller amounts of 2,6‐dihydroxytoluene, m‐hydroxybenzoic acid, 6‐methylsalicylic acid, methylphloroglucinol, salicylic acid, 2,4‐dihydroxytoluene, and several other phenols. Phenols derived from p‐hydroxycinnamic acid were not found. A phenoloxidase was found in mature cells which rapidly oxidized mixtures of the phenols with the formation of polymers. The polymer is highly resistant to microbial degradation in soil and is similar to soil and other fungus humic acids with respect to elemental composition, exchange capacity, and total acidity. The fungus transforms or utilizes numerous phenols as carbon and energy sources.
Factors Influencing Ammonia Losses From Urea Applied to Northwestern Forest Soils
Authors: Watkins S. H. , Strand R. F. , DeBell D. S. , Esch J. 
Published: July 2010

AbstractLaboratory studies indicated that volatilization losses of NH3 increased with increasing air movement, temperature, and pH of mineral soils and forest floors. At an air flow rate of 3 liters/min (equivalent to calculated air velocity of approximately 0.01 km/hour) and temperature of 19°C, losses were high—ranging from 6 to 30% of the urea N applied to bare mineral soils and 27 to 46% for mineral soils covered by forest floors. Ammonia losses were less for mixtures of NH4Cl and urea crystals than for urea crystals or pellets alone. Losses were not related to urea pellet size.
On the Calculation of Hydraulic Conductivity
Authors: Jackson Ray D. 
Published: July 2010

AbstractMethods for calculating hydraulic conductivities of porous materials proposed by Marshall and by Millington and Quirk are similar except for the pore interaction term. This term was shown to be a constant for the Marshall method. Using a matching factor, equations for the two methods differ only by the exponent of the pore interaction term, being 0 for Marshall's method and 4/3 for Millington and Quirk's. Data for four porous materials, for which the hydraulic conductivities, pressure heads, and water contents were determined on the same sample, were used in a statistical procedure to obtain a best fit value for the exponent. For the four materials, an exponent of 1 adequately predicted the measured conductivities. With this exponent, hydraulic conductivities for a field soil were calculated from a laboratory‐determined pressure headwater content relation. Calculated and measured conductivities agreed to within the limits of error of measurement.
Clay‐Water Interaction, the Behavior of 3H and 2H in Adsorbed Water, and the Isotope Effect
Authors: Stewart G. L. 
Published: July 2010

AbstractReference clay minerals and a field kaolinitic soil were allowed to equilibrate with water tagged with tritium and deuterium. Ratios of tritium and deuterium concentrations of tenaciously adsorbed water to respective concentrations of bulk pore water were approximately equal to one for all soils and clay minerals tested. This suggests that no significant isotopic fractionation occurs in adsorbed water. Thermodynamic theory, relating isotopic fractionation to the energetics of adsorbed water, also predicts that isotopic fractionation is not a function of the energy status of adsorbed water. Data from another experiment, where oven dry samples equilibrated with water vapor in a controlled atmosphere, showed that tenaciously adsorbed water on kaolinitic mineral surfaces is not as labile to exchange with the vapor phase as was adsorbed water on montmorillonite and illite surfaces.
Concentrations and Total Amounts of Nutrients in Citrus Seedlings (Citrus sinensis Osbeck) and in Soil as Influenced by Differential Soil Oxygen Treatments
Authors: Labanauskas C. K. , Stolzy L. H. , Handy M. F. 
Published: July 2010

AbstractThis greenhouse experiment was conducted to evaluate the soil oxygen effects on concentrations and total amounts of nutrients in citrus seedlings (Citrus sinensis Osbeck) and in the soil medium in which the plants were grown.Reduction in amount of soil oxygen to the roots significantly decreased N, P, K, Ca, Mg, Zn, Cu, Mn, B, and Fe concentrations in the leaves, and increased these elements in the roots. A significant increase in concentration of Na, Cl, and N, and a decrease of K, Ca, and Mg in the stems was caused by the low level soil oxygen.Total amounts of P, K, Ca, Mg, Cl, Zn, Cu, Mn, and B per whole plant were significantly lower when grown under the low soil oxygen supply. Soils supplied with low levels of soil oxygen contained higher concentrations of NO3‐N and Ca than soils treated with the normal level of soil oxygen.Low level soil oxygen resulted in an increase in Na and Cl concentrations in the stems only, and not, as had been previously assumed, in the leaves.Soil oxygen effects on the uptake and translocation of nutrients in plants cannot be assessed solely on the basis of the nutrient concentrations in the plant leaves. Consideration of plant dry weight and total mineral content per plant are essentials in studying the experimental relationship of soil oxygen to the plant nutritional status.
The Effect of Ammoniacal Nitrogen on Lettuce (Lactuca sativa) and Radish (Raphanus sativus) Plants
Authors: Weir B. L. , Paulson K. N. , Lorenz O. A. 
Published: July 2010

AbstractThe relationship of the growth of radish and lettuce plants to pH, NH3, and NH4+ concentration of the nutrient solution was determined by the use of stepwise multiple regression. Data were collected from plants grown in nutrient solutions with a factorial arrangement of pH (6, 7, and 8) and ammonical nitrogen (0, 10, 20, 30, 40, 60, and 90 ppm of N). The equations obtained for radish and lettuce, respectively, were: Y = 0.479 + 0.00242 X13 + 0.0207 X2 − 0.605 X3 + 0.0133 X33 + 0.0200 X4 − 0.000746 X42 + 0.00000551 X43 and Y = 5.571 − 0.551 X1 − 0.00111 X23 − 0.605 X3 + 0.0171 X33 + 0.0428 X4 − 0.000753 X42 + 0.00000327 X43 where Y was grams of dry matter/plant, X1 was pH, X2 was H+ cone x 107, X3 was NH3 conc. (ppm of N) and X4 was NH4+ conc. (ppm of N). Both equations were significant at the 0.5% level and had R2's of 0.575 and 0.646, respectively. The response of the two species to pH and H+ differed, with radish having its optimum growth at pH 8 and lettuce at pH 7. Their responses to NH3 and NH4+ were very similar. Growth was reduced as the NH3 conc. increased and was increased as the NH4+ conc. increased to an optimum level of 17 ppm of NH4+‐N for radish and 36 ppm for lettuce.
A Study of the Uniqueness of the Soil Moisture Characteristic During Desorption by Vertical Drainage
Authors: Vachaud Georges , Vauclin Michel , Wakil Michel 
Published: July 2010

AbstractPrevious experiments concerning the desorption of a horizontal column of uniform soil suggested that the moisture characteristic was not unique throughout the column. Further desorption experiments have been carried out on a vertical column. The results are consistent with those obtained previously, and give further information on the dual dependence of ψ on θ and on ∂ψ/∂t.
Hydraulic Conductivity Evaluation of the Soil Profile from Soil Water Retention Relations
Authors: Bruce R. R. 
Published: July 2010

AbstractEvaluation of the water content‐suction relation applicable to field soil horizons that differ widely in texture was considered. Except for coarse‐textured, organic matter‐deficient horizons, it is concluded that soil water retention of sieved samples is significantly modified and does not represent the natural soil volume. Water content‐suction data from measurements on carefully procured core samples of each horizon of a Typic Hapludult adequately represent their water retention characteristics. Using appropriate water content‐suction data, the hydraulic conductivity‐water content relation calculated by published procedures was compared with hydraulic conductivity measured on similar samples by a transient outflow procedure. The calculated hydraulic conductivity‐water content relations for coarse grained systems or systems having a relatively narrow range of pore size and well‐defined bubbling pressure was sufficiently accurate for many purposes. However, to obtain a useful evaluation of the unsaturated hydraulic conductivity of fine‐textured horizons with a very wide range of pore size and a poorly defined bubbling pressure, the Marshall or Millington and Quirk methods had to be matched at a water content in the 0.1‐ to 0.3‐bar range. Indiscriminate use of such methods of calculating hydraulic conductivity is inadvisable.
Potassium‐Calcium Exchange Coefficients in Clay Fractions of Some Vertisols
Authors: Knibbe W. G. J. , Thomas G. W. 
Published: July 2010

AbstractPotassium‐calcium exchange equilibria of the following representative Vertisols were determined: Houston Black, Montell, Beaumont, and Houston. Wyoming bentonite and the clay from a Miller soil were included for comparison. Exchange equilibria were expressed in terms of the Gapon equation. The Gapon coefficient KG of the soil clay fractions at high (>18%) K‐saturation were 4 to 5 times higher than for Wyoming bentonite and increased sharply with decreasing K‐saturation. On the basis of X‐ray diffraction data and total K analyses, it was concluded that the highly montmorillonitic clay fractions are interstratified with mica. Specific surface areas were determined relative to Wyoming bentonite. Charge densities (Γ) were expressed as the ratio's Γ soil clay/Γ Wyoming bentonite.Differences in the affinity for K at low K‐saturation were closely related to mica content. The shape of the KG vs K‐saturation curves was explained by the hypothesis that three different sites are available for K adsorption: edge‐interlayer sites of mica, wedge‐shaped sites which might easily form between mica‐montmorillonite layers with graded K selectivities, and planar sites mainly on the montmorillonite.Total chemical analyses of the fine clay fraction of Houston Black and Montell indicated that the high charge density originates mainly in the octahedral layer.
Fertilizer Responses in Young Pine Plantations
Authors: Pritchett W. L. , Smith W. H. 
Published: July 2010

AbstractRegional fertilizer trials were installed in 28 young pine plantations in the US Lower Coastal Plains in 1968. Three randomized complete blocks consisting of a 32 + 2 factorial experiment were included at each site. Soil samples were collected to help characterize the sites physically, chemically, and biologically. Site preparation, planting and fertilization methods were uniform from site to site. Survival was influenced by site properties and fertilizer treatment. On well‐drained sites N reduced survival. Height growth response varied from none on dry sands to as much as 130% increase on some wet sites. Nitrogen significantly affected tree growth in 53% of the tests; but on P deficient sites, N applied alone had little influence on tree growth. Phosphorus additions increased growth in 63% of all tests and 82% of the tests located on poorly‐drained sands. The number of trees damaged by tip moths (Rhyacionia spp) averaged 10% or more in only 18% of the tests. In these experiments, P and K applications apparently reduced the number of trees attacked. Almost 22% of the trees in all tests were infected with Cronartium fusiforme Hedge. However, 40% of the tests had less than 5% infection. In tests where rust was severe, the percentage of rust‐infected trees increased with fertilization. Fertilization, especially with K, appeared to reduce insect attacks. Species composition of the ground cover was altered by treatments.
The Relationship of Red Pine Site Index to Soil Phosphorus Extracted by Several Methods
Authors: Alban David H. 
Published: July 2010

AbstractPhosphorus was extracted by 10 methods from soils in Minnesota supporting stands of red pine (Pinus resinosa Ait.) to find those methods most suitable for estimating site index. The amount of phosphorus extracted from the surface 25 cm of mineral soil by H2O, 0.002N H2SO4, or 0.01N HCl was related at the 1% level (r2 = .47 to .53) to site index. Considerably weaker relationships with site index were obtained with organic P, total P, and phosphorus extracted by 0.5N NaHCO3, 0.4N HCl, 0.025N HCl + 0.03N NH4F, 0.10N HCl + 0.03N NH4F, or 0.05N HCl + 0.025N H2SO4. No improvement in the estimation of site index was made by including phosphorus extracted from deeper layers of the soil. Foliar phosphorus concentration was significantly related to site index and to the amount of phosphorus extracted from the surface soil by H2O, 0.002N H2SO4, or 0.01N HCl.
Substances Contributing to Fire‐Induced Water Repellency in Soils
Authors: Savage S. M. , Osborn J. , Letey J. , Heaton C. 
Published: July 2010

AbstractA soil susceptible to heat‐induced water repellency was heated at several temperatures and oxygen concentrations. The materials emanating from the heated soil were captured and their mass determined. The greatest quantity of products was captured at temperatures above 300C. Increasing amounts of material were produced with increasing oxygen concentrations up to 20%. From 0.3% to 1.75% of the total soil was captured as products.Fractionation of these captured products by adsorption chromatography resulted in the isolation of several different components. Three of these components were capable of causing extreme water repellency in sand if the treated sand were heated. Some evidence suggested that the heating of these substances on the sand surfaces altered their structure. These three effective components represented from 25–50% of the total materials collected from the soil.Elemental and spectroscopic analyses of the effective components indicated them to be basically aliphatic hydrocarbons.The undecomposed and partially decomposed plant materials present in the soil were determined to be the primary source of the products coming from the heated soils.