bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Measurement of Water Loss by Mesquite (Prosopis glandulosa var. glandulosa Torr.) Using the Thermoelectric Method
Authors: Wendt C. W. , Runkles J. R. , Haas R. H. 
Published: July 2010

AbstractThe quantitative aspects of the thermoelectric method were investigated in a controlled environment chamber using mesquite (Prosopis glandulosa var. glandulosa Torr.). A high degree of correlation for trees less than 10 mm in diameter (r = 0.97) was obtained between water transpired and the product of the cross‐sectional area of the stem and the relative sap velocity. As the size of trees increased the correlation decreased due to variations in relative sap velocities around the circumference of larger trees. Although the correlation coefficient was high for trees less than 10 mm in diameter, the coefficient of variation was 15.6% which was probably due to the variation in the moisture content of the plants.
Soil Atmosphere as Influenced by Temperature and Moisture
Authors: Yamaguchi M. , Flocker W. J. , Howard F. D. 
Published: July 2010

AbstractComposition of the atmosphere of Yolo sandy loam soil columns was determined at different depths and different soil moisture conditions. After saturation with water, soil columns were placed in 30, 25, 20, 15, or 10C constant temperature rooms and moisture was allowed to evaporate from the soil surface. Soil moisture content was determined with a gamma‐ray densitometer; CO2, O2, and N2 concentrations were determined by gas chromatography. After 14 days at 30C, moisture tension at the 65 cm depth was 0.1 bar and the soil atmosphere contained 17% CO2 and 4% O2. At the 35‐cm depth, the moisture was 0.3 bar and the CO2 and O2 concentrations were 7% and 14%, respectively. At the 5‐cm depth the CO2 did not rise over 1.5%. At lower temperatures the CO2 did not rise over 1.5%. At lower temperatures the CO2 concentrations were less and the maximum was reached more slowly. However, the N2 concentration increased to almost 90%. At each temperature and all depths, rapid changes occurred in the concentration of gases when the soil moisture tension reached 0.10 to 0.15 bar.
Reactions of Ammonium Polyphosphates with Soil Minerals
Authors: Philen Otis D. , Lehr James R. 
Published: July 2010

AbstractWhen suspended in solutions of ammonium pyro‐ or tripoly‐phosphates at room temperature, calcium and magnesium carbonates reacted rapidly and clay minerals and hydrous oxides of iron and aluminum reacted slowly. The precipitated solid products of the reactions included calcium and magnesium ammonium pyro‐ and tripolyphosphates and iron and aluminum ammonium pyrophosphates but no tripolyphosphates; no solid orthophosphates were formed. The condensed phosphates were much less reactive with the soil minerals than are orthophosphates.
Interaction of Ammonium and Potassium in a Potassium‐Fixing Soil
Authors: Bartlett R. J. , Simpson T. J. 
Published: July 2010

AbstractDifferent levels of NH4 and K were supplied to a K‐fixing soil (Buxton silt loam) containing the nitrification inhibitor 2‐chloro‐6‐(trichloromethyl) pyridine. Maize (Zea mays L.) seedlings were grown in the soil under controlled conditions.

When K was equilibrated with this soil first, adidtion of NH4 had almost no effect on the availability of K, as indicated by extraction with NaOAc or by uptake of maize seedlings.

Equilibration of the soil with NH4, before the addition of K, increased the amount of K extracted, increased the percentage of K in the p ants, and increased the yields of seedlings.

Addition of NH4 at the same time as K was at least as effective as its addition before K in increasing yields as we 1 as amount of K taken up by the plants or extracted chemically from the soil.
Seepage of Steady Rainfall through Soil into Ditches of Unequal Water Level Heights
Authors: Powers W. L. , Kirkham Don , Snowden G. 
Published: July 2010

AbstractA theoretical solution and numerical results for the seepage of steady rainfall into soil laying above an impermeable layer and drained by ditches of unequal water level heights is obtained for the ditches just reaching or penetrating into the impermeable layer. This is done by using a finite series of orthonormal functions generated from products of trigonometric and hyperbolic functions. The theoretical solution gives the potential function and stream function for a range of water level heights, ditch spacings, and a range of ratios R/K of rainfall rate R to hydraulic conductivity K. If R/K is increased from 0 to 0.05, for 10‐m spacing of ditches and for 1 ditch having water maintained 1 m above the barrier and the other ditch 1.5 m; then the maximum water table height in the soil will increase from 1.50 m to 1.82 m. Also, as R/K increases, the position of the maximum water table height will approach a position midway between the ditches. Flow nets and other results computed for a number of geometries from the theory bring out additional information.
Determination of Iron with Thiocyanate
Authors: Hsu Pa Ho 
Published: July 2010

AbstractThe effects of acidity and concentration of thiocyanate on the intensity and stability of the iron‐thiocyanate color solution were studied in detail, and a procedure was proposed. In the proposed procedure, a combination of 3 ml of 6N HCl and 10 ml of 20% KSCN is recommended. In the presence of this amount of KSCN, the color intensity was constant while the amount of HCl varied from 5 to 30 meq. Hydroxy‐iron polymers in the sample solution can be decomposed by heating the aliquot in the presence of acid prior to the addition of KSCN. By adding H2O2 at the end of the procedure, it is possible to confine the reading time within a short interval and thus overcome rapid color fading.
The Effect of Water Content on Axial Strain in a Loam Soil under Tension and Compression
Authors: Farrell D. A. , Greacen E. L. , Larson W. E. 
Published: July 2010

AbstractA method is described for measuring axial strain in a remolded loam soil under unconfined axial loading in both compression and tension. Using this method the stress‐strain relationships for the loam soil were determined for soil‐water contents ranging from 2% to 12% by weight.The maximum tensile stress in a soil beam stressed to failure in a modulus of rupture test was computed from the measured stress‐strain relationships. This computed fiber stress was approximately 10% greater than the measured tensile strength.The strain energy required to rupture this soil in axial tension, taken as the area under the stress‐strain curve, was shown to increase by only 20% for a sixfold increase in tensile strength and to be almost proportionately related to the energy required to produce a fixed degree of soil breakup in a drop‐shatter test.
Hydraulic Properties of Disturbed Soil Materials Affected by Porosity
Authors: Laliberte G. E. , Brooks R. H. 
Published: July 2010

AbstractRecently some hydraulic properties of porous materials have been described for use in constructing valid physical models that are easily measured and practically significant. These properties have been used to express similitude requirements for drainage of initially saturated soils.This paper describes how soil packing effects the hydraulic properties of three soil materials. Soil packing as measured by bulk density and porosity is related to bubbling pressure, poresize distribution index and permeability. With a light hydrocarbon oil as the wetting fluid the pore‐size distribution index was changed only slightly over a wide range of porosities. Permeability and bubbling pressure, on the other hand, were changed severalfold over the same range of porosities.For modeling purposes, one requirement for similitude between model and prototype is identical values of pore‐size distribution index. Evidently, bubbling pressure may be adjusted to suit the size of the model by changing the packing density without appreciably changing the pore‐size distribution index.
Tillage Pan Characterization of Selected Coastal Plain Soils
Authors: Kashirad A. , Fiskell J. G. A. , Carlisle V. W. , Hutton C. E. 
Published: July 2010

AbstractTillage pan characteristics in Lakeland, Norfolk, Red Bay and Orangeburg soil series were studied at 20 paired locations of cultivated and virgin areas. Pits for sampling were dug following periods of heavy rainfall. Tillage pans were identified by pocket penetrometer readings of the compaction. Sampling depths from adjacent virgin sites corresponded to those in the cultivated sites. These pans showed consistently higher compaction, bulk density, and less pore space than the soil above or below the pan or the corresponding adjacent virgin soils. Sand, silt, and clay contents were not significantly different between virgin and cultivated samples.Sequential extraction with hydrogen peroxide, dithionite‐citrate, and 0.5N NaOH was made of the cultivated and virgin soils for depths above, in, and below the pan. Dithionite‐citrate extraction for free Fe removed less Al and Si than the subsequent extraction with 0.5N NaOH. Accumulations of Fe, Al, and Si were significantly greater in the pan but these were not consistent for each soil series. Organic matter probably helped to filter and encourage accumulations of some compounds in the pan which might be important in cementation properties. Roots either failed to penetrate these tillage pans or were constricted to much poorer lateral growth compared to roots above or below the pan.
Soil‐Water Properties Computed from Transient Flow Data
Authors: Weeks L. V. , Richards S. J. 
Published: July 2010

AbstractA method is given for calculating water conductivity (K) of unsaturated soil by the use of data obtained during transient changes of moisture content (θ) and suction head (h) along a horizontal soil column. A soil moisture characteristic curve was obtained from the data. Absolute values of the slopes of the latter curve, the differential water capacity (C), pertaining to the experimental values of h were then used to calculate soilwater diffusivity (D) from the equation, D = K/C. The experimental procedure does not involve boundary conditions that, in some procedures, are difficult to evaluate, nor are steady‐state and equilibrium‐flow conditions required. Data for most soils was obtained in from 8 to 12 days. A program was written in Fortran IV language for use with the IBM 7040 Data Processing System. The solution of the problem was reduced to a routine that saves several hours of hand calculations.Values of K, C, and D for field cores and laboratory compacted soil columns were measured over the range of 50 ≤ h ≤ 750 cm of water. Relative error values between measured values of K and those calculated from the equation K = ch‐d were less than 50% in 83% of 288 measurements. Relative error values between measured values of D and those calculated from the equation D = α exp (βθ) were less than 50% in 74% of the 288 measurements. The constants, c, d, α, and β are empirical for a given soil. Water conductivity values were shown to be independent of hydraulic gradients over a wide range of gradient values.
Mineralogical and Chemical Characteristics of Soils in Loess Overlying Shale in Northwestern Illinois
Authors: Jones Robert L. , Ray B. W. , Fehrenbacher J. B. , Beavers A. H. 
Published: July 2010

AbstractEleroy and Derinda soils (Typic Hapludalfs) and Keltner and Schapville soils (Typic Argiudolls) were studied. Weathering of silt‐size minerals is not advanced in these relatively youthful soils. Iron is the most sensitive indicator of weathering, being particularly labile in the Hapludalf profiles. Iron weathers from silt‐size minerals and is localized in concretions and in the clay fraction. Clay‐mineral weathering involves formation of chloritized vermiculite and montmorillonite from illite and montmorillonite precursors. The stage of weathering of these soils approximates that in Clinton, Fayette (Hapludalfs), and Tama (Argiudoll) soils that occur along the Mississippi River. Soil test values for K and P and amounts of exchangeable K and total P are high. Productivity is related more to depth of underlying shale and attendant physical effects than to nutrient status.
Soil Survey Refinements for Predicting Black Oak Site Quality in Southeastern Ohio
Authors: Carmean Willard H. 
Published: July 2010

AbstractSoil‐site studies in southeastern Ohio reveal the need for soil survey refinements for accurate classification of black oak (Quercus velutina Lam.) site quality. These studies also have identified the specific soil and topographic features closely related to oak‐site quality. This information is used as a basis for designing mapping units for more accurate estimation of oak‐site quality. Existing soil series are combined into two “woodland suitability groups,” each of which includes soils similar in average site quality and soil morphology. Then these two groups are phased, using the specific soil and topographic features known to be closely related to oak‐site quality. A large number of multiple regression equations are available for calculating the required phases, but equations based only on topographic features explain more than 75% of the height variation. They are the most practical for forest‐site quality phasing because they can be easily applied by using aerial photographs and topographic maps. The exceptional precision of the topographic equations is due to correlations between topography and soil features significantly related to oak site quality. Such close correlations have long been recognized by soil surveyors as a basis for delineating boundaries of soil mapping units. Hence, using these correlations as a basis for phasing for site estimation is a logical extension of present survey practices.
The Adsorption of Atrazine and Atratone by Anion‐ and Cation‐Exchange Resins
Authors: Turner M. A. , Adams R. S. 
Published: July 2010

AbstractThe adsorption of two herbicides, atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine), and atratone (2‐methoxy‐4‐ethylamino‐6‐isopropylamino‐s‐triazine), was studied using a cation‐ and an anion‐exchange resin saturated with selected ion species. The amount of herbicide adsorbed was found to vary with the herbicide and with the ion present at the exchange site. Both atrazine and atratone were adsorbed by the cation‐ and anion‐exchange resins, but atratone exhibited the more pronounced affinity for the cation saturated resins.The data in this study suggested the possibility of complex formation between the herbicide molecule and certain cations present at the exchange site of the resin as a mechanism for adsorption. The further use of resins for evaluating herbicide adsorption mechanisms is advocated.
Relation between Landform Parameters and Soil Properties
Authors: Walker P. H. , Hall G. F. , Protz R. 
Published: July 2010

AbstractLandform parameters of slope gradient, slope length direction, curvature, distance from the hillslope summit, and elevation relative to the summit were recorded with soil profile observations across small loess and drift landscapes in Iowa. Simple regression and correlation analyses were used to examine the relationship between each soil property and the parameters and also the relationships among parameters. The geomorphic parameters were then fitted to soil data in different combinations in multiple regression. Generally, elevation and slope were most strongly related to the soil properties measured. Slope length direction was also an important parameter for A horizon thickness and subsoil mottle features. When two of the sites were subdivided into convex and concave areas, significant regressions were again obtained. Nevertheless, considerable soil variation remained unaccounted for. This may result from the relict nature of some of the subsoil features, or in the case of A horizons, from faunal activity.
Soil Reflectance, Temperature, and Fallow Water Storage on Exposed Subsoils of a Brown Soil
Authors: Black A. L. , Greb B. W. 
Published: July 2010

AbstractThe topsoil of a Weld soil on an 0.84% slope was removed, giving an increasing depth of subsoil exposure ranging from 0 to 38.1 cm over a horizontal distance of 45.7 m. Five subranges of subsoil exposure—0 to 7.6, 7.6 to 15.2, 15.2 to 22.8, 22.8 to 30.4, and 30.4 to 38.1 cm—were formed with each subrange corresponding to a horizontal distance of 9.14 m. The exposed surface 5 cm of these soil removal treatments differed in texture, structure, reflectance, clod bulk density, aggregate stability, and wind‐erodible soil fraction.Over a 5‐year period, mean fallow efficiency for all five soil removal treatments ranged from 25.6 to 38.5%. Reflectance of the exposed surface 5 cm of soil of each soil removal treatment varied considerably among treatments. Mean soil temperatures in fallow were negatively correlated with visual efficiency (P = .05) which was used as an indirect value of soil reflectance. Average soil water gained in fallow was negatively correlated (P = .05) with the mean fallow soil temperature measured at a depth of 7.6 cm. The negative correlation between soil water gained and mean soil temperature was significant (P = .01) in a dry year (1960) and nonsignificant (P = .05) in a year of above‐average precipitation (1957). A positive correlation was obtained between soil water gained during fallow and visual efficiency (P = .10).Soil water storage in fallow and depth to seedbed water were influenced by soil texture and aggregation in some years. No significant relationship was found between soil water storage at the end of fallow and subsequent crop production because of interactions involving soil temperatures and fertility levels.
Analysis of Steady‐State Evapotranspiration from a Soil Column
Authors: Whisler F. D. , Klute A. , Millington R. J. 
Published: July 2010

AbstractNumerical analysis is applied to the steady‐state flow equation for evapotranspiration from a vertical soil column. The water uptake by the plant roots is incorporated into the flow equation as a (negative) source term. The evapotranspiration rate and its partitioning between plant transpiration and soil evaporation are specified as the top boundary condition. The lower boundary condition is a water table. The results of the analysis for a Pachappa sandy loam give pressure head, water content, source strength and soil water flux profiles. This study has (i) demonstrated that solutions to the flow equation with a source term can be obtained by numerical means, (ii) shown something of the theoretical influence of the parameters in the source term model on the flow in the soil, (iii) qualitatively indicated a transfer of water from wet soil via the root system, and (iv) indicated that the source term has little effect on the pressure head profile unless the evapotranspiration rate is about the same order of magnitude as the theoretical limiting value.
Adsorption of Organic Herbicides by Montmorillonite: Role of pH and Chemical Character of Adsorbate
Authors: Bailey G. W. , White J. L. , Rothberg T. 
Published: July 2010

AbstractSamples of well‐characterized 1‐0.2µ montmorillonite clay adjusted to two pH values, pH 3.35 and 6.80, were reacted with members of such herbicide families as s‐triazines, substituted ureas, phenylcarbamates, aniline, anilides, phenylalkanoic acids, benzoic acids, and picolinic acids.Graphical methods were used to plot adsorption isotherms and to determine conformity to the Freundlich or Langmuir equations. Calculations were made to determine: (i) the percent cation exchange capacity satisfied at the maximum amount adsorbed; (ii) the percent surface coverage at the maximum amount adsorbed; and (iii) the partial molar‐free energy for each concentration level; also determined graphically was the Freundlich “K” and “1/n” value.Conformity to the Freundlich adsorption equation was found for all organic compounds studied for both the H‐clay and the Na‐clay systems with two possible exceptions: the phenoxyacetic acid‐H‐clay system and the substituted urea‐Na‐Clay systems. Conformity to the Langmuir adsorption equation was not found for any family or group studied on either H‐ or the Na‐saturated clay.Regardless of chemical character, adsorption occurred to the greatest extent on the highly acid H‐montmorillonite compared to the near neutral Na‐montmorillonite.Within a family or within an analog series basic in chemical character, the magnitude of adsorption is related to and governed by the degree of water solubility. The major factor governing the magnitude of adsorption of different basic chemical families is the dissociation constant of the adsorbate.The magnitude of adsorption of organic compounds with widely different chemical character is governed by the degree of water solubility, the dissociation constant of the adsorbate, and the pH of the clay system.The adsorption of basic organic compounds by the montmorillonite type clay system appears to be dependent upon surface acidity and not upon the pH of the suspension while the converse appears to hold true for the adsorption of acidic type compounds.The surface acidity of montmorillonite appears to be 3–4 pH units lower than the suspension pH.Mechanisms for the adsorption of basic and acidic organic compounds are discussed.
Moisture Characteristics of Pennsylvania Soils: I. Moisture Retention as Related to Texture
Authors: Petersen G. W. , Cunningham R. L. , Matelski R. P. 
Published: July 2010

AbstractSoil moisture retentions are associated with similar soil properties within each textural class of the USDA Textural Classification and family grouping of the New Classification System. Multiple regression analyses showed bulk density most strongly associated with ⅓ atm moisture (core samples) and clay content with 15 atm moisture (<2 mm sieved samples). Organic carbon was also associated with 15 atm moisture but not with ⅓ atm moisture. Available moisture, as determined by the difference between ⅓ atm and 15 atm moisture, was negatively correlated with sand and clay and positively correlated with silt content. Available moisture was also highly correlated with ⅓ atm moisture whereas 15 atm moisture showed either no correlation or a negative correlation.Scatter diagrams, with corresponding quadratic equations for the line of best fit, allow determinations of ⅓‐atm and 15‐atm moisture contents from known clay percentages. Prediction equations, for estimating available moisture from predetermined soil properties, are given for each textural class, with the exception of sand and sandy clay, and for each textural class of family grouping in the New Classification System.
The Variability of Forest Soils of the Georgia Blue Ridge Mountains
Authors: Ike Albert F. , Clutter Jerome L. 
Published: July 2010

AbstractData collected from 123 forested plots in the Blue Ridge Mountains of northeast Georgia were used to (i) evaluate sample stratification criteria, (ii) estimate the variability of physical and chemical properties of the soil, and (iii) examine the efficiency of sampling schemes.Sample stratification seemed justified on the basis of soil series, but not on the basis of soil type. For similar soils, maximum efficiency in estimating means of soil series is obtained with one or two pits per plot. The number of plots (pedons) required for adequate precision is greater than the number customarily sampled for soil series characterization studies.Sampling to estimate plot mean values in soil‐site studies involves consideration of the variances of several properties to be estimated from one soil sample. The use of two to four pits (profiles) per plot in similar soils would seem to be adequate for most but not all commonly measured soil properties.