bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of Relative Value of Phosphate Rock and Superphosphate to Plants on Different Soils
Authors: Peaslee D. E. , Anderson C. A. , Burns G. R. , Black C. A. 
Published: July 2010

AbstractThe relative value of phosphate rock and superphosphate as sources of P for plants was evaluated by a test crop of sorghum on 19 soils in greenhouse cultures. The results were expressed as availability‐coefficient ratios. In the laboratory, three sets of measurements were made of P extractable from untreated soil, phosphate‐rock‐treated soil, and superphosphate‐treated soil: (1) P extracted by 0.025N HCl, 0.03N NH4F solution used in a ratio of 1 part of soil to 50 of solution by weight (method of Bray and Kurtz modified by Smith and Grava) after a 30‐day incubation period, (2) P extracted by an anion‐exchange resin without prior incubation, and (3) P extracted by an anion‐exchange resin after incubation for 30 days. Methods 2 and 3 were modifications of the method of Amer et al. The results were expressed as extractability‐coefficient ratios. The correlation between availability‐coefficient ratios and extractability‐coefficient ratios was highest with method 2 and lowest with method 1. The correlation between soil pH values and availability‐coefficient ratios was equally as close as that obtained between availability‐coefficient ratios and extractability‐coefficient ratios by method 2.
Measurements of Soil Moisture Diffusivity from Tension Plate Outflow Data
Authors: Bruce R. R. , Klute A. 
Published: July 2010

AbstractA tension plate apparatus was designed for measuring volume of water outflow from samples of porous material as a function of time. Volume outflow was measured from samples of glass beads and sand at moisture tensions < 200 cm. of water. In the calculation of moisture diffusivity, published theory and procedures were used. The experimental volume outflow of water in the low moisture tension range of all porous materials studied did not agree with that predicted by presently developed theory. Agreement with theory apparently improved in the higher tension range. This disagreement of theory and experiment is not presently explainable. Values of moisture diffusivity were calculated by fitting the outflow data near (Q∞ ‐ Qt)/Q∞ equals 0.5. Although the accuracy of these moisture diffusivity values is uncertain, the general nature of the moisture diffusivity‐moisture tension relationship is shown.
Effects of Temperature and Moisture on Phosphorus Uptake from a Calcareous Saskatchewan Soil Treated with Several Pelleted Sources of Phosphorus
Authors: Beaton J. D. , Read D. W. L. 
Published: July 2010

AbstractThe effects of temperature, moisture, and P source during the initial soil‐fertilizer reaction period on subsequent P uptake by oats were investigated in a growth chamber. Phosphorus‐treated soil with moisture adjusted to four different tensions was stored at 5°, 16° and 27°C. for 1 week and for 7 weeks. Following these storage intervals, P uptake by oats was measured using a shortterm method.Uptake of P from soil treated with mono‐ and diammonium phosphates was greater following reaction of the fertilizer with soil at 5°C. than at either 16 or 27°C. No significant differences between 16° and 27° were observed.Moisture tension during the I‐week reaction period did not influence P uptake. Following the 7‐week reaction period, uptake of P was favored by the 2.0‐bar moisture tension treatment. It was lowest from soil reacted at 0.4 bar. Water‐soluble sources such as monocalcium phosphate and mono‐ and diammonium phosphates were the most sensitive to differences in moisture.Availability of the source decreased in the order mono‐ammonium phosphate > diammonium phosphate > mono‐calcium phosphate > dicalcium phosphate dihydrate > anhydrous dicalcium phosphate > check.
The Leaching of Radiostrontium and Radiocesium Through Soils
Authors: Miller J. R. , Reitemeier R. F. 
Published: July 2010

AbstractSr90 and Cs137 are hazardous, long‐lived, nuclear fission products. Experiments were conducted in the greenhouse to determine their downward movement in soils under intensive leaching. The five soils (Norfolk, Hagerstown, Miami, Fort Collins, and Huntley series) selected for the investigation represented a wide range of soil properties, and the leaching treatments consisted of 30 inches and 300 inches of deionized water, 0.005N NaCl, and 0.005N CaCl2. There was little downward movement of Cs134 when the soils received the applications of deionized water, NaCl, or CaCl2. Radioactive assays of the soil columns showed that 96.6 to 100% of the Cs134 was in the surface two layers of the soil columns (average depth 1.4 inches) after 300 inches of leaching. In the leaching experiment with Sr, the CaCl2 produced the greatest movement of Sr89 and deionized water the least. The maximum distance Sr89 penetrated into the soils when leached with 30 inches of water was 1.3 inches, and with 300 inches of water the distance was 4.3 inches. In general, there was more movement of Sr89 in the Norfolk soil and least in the Huntley, with the other soils being intermediate.
Decay of Phosphate Fertilizer Reaction Products in an Acid Soil
Authors: Taylor A. W. , Gurney E. L. , Lehr J. R. 
Published: July 2010

AbstractComplex iron and aluminum phosphates that may be formed by the reaction of concentrated acidic phosphate solutions with soil minerals were incubated in a moist acid soil for 10 months. Potassium ferric phosphate, H8KFe3(PO4)6·6H2O, and calcium ferric phosphate, H4CaFe2(PO4)4·5H2O, dissolved incongruently with release of part of their phosphate to the soil and formation of strengitic residues. Potassium taranakite, H6K3Al5 (PO4)8·18H2O, was more stable; it persisted throughout the incubation period and released smaller amounts of phosphate. Amorphous iron and aluminum phosphates also persisted throughout the incubation period, and their rates of dissolution appeared to be controlled by the rate of diffusion of their phosphate into the surrounding soil.
Metallo‐Organic Interactions Associated with Podzolization
Authors: Wright J. R. , Schnitzer M. 
Published: July 2010

AbstractLeaching a calcareous soil parent material with a chelating agent caused the mobilization, transport, and redeposition of iron and aluminum resulting in the formation of a profile similar to those of certain podzolic soils. Under natural conditions, fulvic acid is considered to be the dominant ligand effecting the translocation of iron and aluminum in the podzolization process. Oxidative degradation studies and infrared and functional group analyses suggest that fulvic acid consists of an aromatic “nucleus” to which carboxyls, hydroxyls, and carbonyls are attached as the main functional groups. There is a strong possibility that on its path down the profile this fulvic acid forms, at first, water‐soluble multidentate chelates with metals such as iron and aluminum, etc., and that precipitation of these metallo‐organic complexes lower in the profile is effected by further reaction with the same metals and by extremely small amounts of ionic Ca2+ and/or Mg2+.
Effect of Soil Temperature on Corn Plant Development and Yield: II. Studies With Six Inbred Lines
Authors: Jones J. Benton , Mederski H. J. 
Published: July 2010

AbstractSix inbred lines of corn were grown in the field under heated and normal soil conditions. Heating was accomplished using electric heating cables placed under the row. Heating had a marked effect upon the early growth rate and uptake of K, P, and Ca. Heating tended to shorten the period from emergence to silking. All of the inbred lines on the heated rows were shorter than those in the unheated rows at maturity. A differential yield (ear and fodder) response to soil heating was obtained among the inbreds. The differential response among the inbreds may explain why varying yield responses to soil heating which have been obtained in different investigations. Inbred lines may be unique plants to use for determining the factors related to the heat stimulus effect.
Soil Water Relations During Rain Infiltration: I. Theory
Authors: Rubin J. , Steinhardt R. 
Published: July 2010

AbstractSoil moisture content changes and rates of water entry during rain infiltration into a semi‐infinite soil column are analyzed mathematically. The model considered involves, principally, the following assumptions: Darcy's and continuity equations are applicable; the soil's hydraulic conductivity and diffusivity are unique, positive, and monotonically increasing functions of soil moisture contents; rainfall entering the soil can be considered as a continuous body of water.It is shown analytically that an incessant rain eventually results in ponding if and only if rain intensity, R, exceeds the saturated soil's hydraulic conductivity, K(wsat). For R ⩽ K(wsat) it is proven that as infiltration proceeds soil moisture contents at increasing depths tend to approach a constant level. At this level the soil's hydraulic conductivity equals the rain intensity. For R > K(wsat) it is indicated how to estimate the water uptake at incipient ponding.A difference method for solving approximately the differential equation of the model in question is described. An illustrative numerical example of this method's results is presented.
Thermal Response of a Dry Surface to Shading Cycles of Short Period
Authors: Federer C. A. , Tanner C. B. 
Published: July 2010

AbstractAn experiment is presented on the thermal response of a nonevaporating surface (concrete) to square‐wave pulses of solar radiation with half‐periods ranging from 2 to 20 minutes. Heat flux into the concrete accounted for most of the net radiation but the data was inconsistent due to inadequate temperature sampling. The amplitude ratio of sensible heat to net radiation was 0.01 to 0.10, increasing with period, surface roughness, and wind velocity in agreement with Lettau's theory for sinusoidal net radiation. The amplitude ratio of surface temperature to net radiation (ΔT0/U0) increased from 1 to 6°C.ly.‐1 min. with increased period. The predicted decrease of ΔT0/U0 with increased roughness was approximately that of the experimental results; however, the observed decrease of the ratio with increased wind speed was greater than that predicted by theory.
A Suggested Mechanism for Sulfate Adsorption by Soils
Authors: Chang Monica L. , Thomas Grant W. 
Published: July 2010

AbstractEquilibrium experiments with SO4‐Cl mixtures suggested that the quantity of anions held by a Cecil subsoil increases with time. Further experiments with K2SO4 confirmed the “time” effect on two Cecil subsoils and on Fe‐treated Georgia kaolinite. On the basis of the time effect and other observations made on SO42‐ adsorption a suggested mechanism is proposed. The mechanism envisions the replacement of OH‐ ions by SO42‐ and the hydrolysis of Al (in the presence of salt) to form H+ ions. Thus, the OH‐ ions are neutralized by H+ ions and anion adsorption proceeds apace.
The Effect of Gamma Radiation on the Availability of Nitrogen and Phosphorus in Soil
Authors: Eno Charles F. , Popenoe Hugh 
Published: July 2010

AbstractThe effects of several levels of gamma radiation ranging from 0 to 2,048 kiloroentgens on the availability of N and P from three fine sands and one peat soil were investigated. Nutrient release was measured chemically and by plant uptake. Irradiation increased the availability of N and P in soils evaluated immediately following irradiation, and after 2 weeks of incubation. This was shown by both chemical and plant uptake measurements. The release of N and P was closely related to soil type and more particularly to its organic matter content. In each case the soil containing the largest amount of organic matter showed the largest increase in extractable N and P after irradiation. An evaluation of the ammonium acetate (pH 4.8) extractable Ca, Mg, and K data indicated that there were no measurable changes in the availability of these elements that could be directly related to irradiation of the soil. The release of N and P, in many soils, will be a significant nutritional factor when plants are grown on irradiated soil.
The Reactions of Extracts from Maple and Oak Leaves with Iron and Zinc Compounds
Authors: Himes F. L. , Tejeira R. , Hayes M. H. B. 
Published: July 2010

AbstractA water extract of oak leaves solubilized more iron from freshly precipitated ferric hydroxide at three pH's than the extract of maple leaves. The influence of the hydrogen‐saturated extracts on the equilibrium of iron and zinc between solution and sodium‐saturated Dowex resin were studied. More iron was solubilized when the extract was present than when absent, and the two extracts were similar. The influence of the extracts on equilibrium with zinc was very small. With paper strip electrophoresis, the iron moved with the extract toward the anode and the zinc moved toward the cathode. The higher molecular weight substances precipitated when the pH of the solution was raised to 5.2. The infrared spectra of the hydrogen‐saturated and iron‐saturated extracts indicate that carboxyl groups are involved in the reaction of iron with the organic constituents of the extract. Since zinc did not react with the constituents in the extract but iron did react, phenolic groups were probably involved in the reactions with iron.
Moisture Retention by Soil with Coarse Layers in the Profile
Authors: Miller D. E. , Bunger Wm. C. 
Published: July 2010

AbstractThe effects of coarse strata on the moisture retention characteristics of soil profiles were evaluated. A sandy loam soil was underlain at various depths by sand or gravel and the moisture status of the soil was observed for 2 months following a heavy irrigation.The moisture retained by soil underlain by sand or gravel was much greater than in similar depths of a uniform soil. The moisture content of the soil above a layer increased as the layer was approached. The moisture content of the soil underlain by sand or gravel changed very little after the first few days following irrigation whereas in the uniform soil moisture moved downward throughout the observation period.The moisture retention characteristics of the profiles were roughly estimated from laboratory measurements of unsaturated conductivities of the sand and gravel and from a moisture characteristic curve of the soil.
A New Calcium Aluminum Phosphate, CaAlH(PO4)2·6H2O
Authors: Lehr James R. , Frazier A. William , Smith J. P. 
Published: July 2010

AbstractDescriptions are given of the optical and morphological properties of CaAlH(PO4)2·6H2O, one of five new acidic calcium aluminum phosphates that may be formed by reaction of phosphatic fertilizers with soil minerals. The new salt has a striking resemblance to CaHPO4·2H2O in its morphological and optical properties, but differs markedly in its X‐ray powder diffraction pattern.
The Influence of Fluoride, Temperature, Calcium, and Alcohol on the Reaction of Cobalt With Montmorillonite
Authors: Hodgson J. F. , Geering H. R. , Fellows Martha 
Published: July 2010

AbstractPretreatment of montmorillonite with F interferes with the adsorption of Co by montmorillonite. Since the effect is reversible with base, the F is thought to replace surface hydroxyl groups that serve as the adsorption sites for Co. The Co reaction with these sites increases with temperature, indicating that the reaction is endothermic. Therefore, either heat is required to form the Co‐to‐surface bond or the cation is replacing more strongly bound surface hydrogens such as those associated with the hydroxyls mentioned above. While certain other heavy metal cations were previously shown to exchange with adsorbed Co, Ca is found to have no effect on the reaction, except to alter the activity coefficient of Co in solution. This is interpreted as indicating the absence of any charge associated with the bonding site. Alcohol is found to enhance the reaction of Co with montmorillonite in contrast to what would be expected if hydrolysis played a role in the reaction.
Precipitation of Phosphate from Calcium Phosphate Solutions by Iron Oxide and Aluminum Hydroxide
Authors: Taylor A. W. , Gurney E. L. , Moreno E. C. 
Published: July 2010

AbstractAluminum hydroxide is the principal reagent in the precipitation of phosphate from fertilizers in acid soils. Iron oxide is much less reactive unless it is very finely divided. In cold phosphate solutions, clay minerals are stable in comparison with hydrated iron and aluminum oxides. The amounts of dicalcium phosphate, calcium aluminum phosphate, and amorphous aluminum phosphate that are precipitated when gibbsite dissolves in potassium‐free acidic calcium phosphate solutions depend upon the rate of dilution of the solution. Amorphous ferric phosphate and calcium ferric phosphate are formed during the dissolution of goethite, but, unless the soil contains a large amount of reactive iron oxide, most of the phosphate will be precipated as aluminum compounds.
Nutrition of Corn on a Calcareous Soil: I, Interrelationships of N, P, K, Mg, and S on the Growth and Composition
Authors: Soofi G. S. , Fuehring H. D. 
Published: July 2010

AbstractA factorial experiment was carried out with irrigated corn grown on a calcareous soil to determine the effect of N, P, K, Mg, and S, both singly and in combination, on the production of grain and stover, and on the composition of the leaves. Multiple regression equations in quadratic logarithmic form were developed in order to elaborate the effects.The soil used was inherently fertile and the first order effect of the nutrients was very small for grain and stover yield. The interaction of Mg and S was significantly positive in effect on grain yield. If application of either Mg or S was high, there was a large positive response to the other, while if application of either Mg or S was low, there was a large negative response to the other. However, for yield of stover the Mg‐S interaction was significant and negative or opposite in effect. The contrasting effect between grain and stover yields was further indicated by the interactions between the three anion nutrients, N, P, and S, which were all negative for grain production and all positive for stover production. The interactions of K and Mg on stover production were opposite in effect. The K‐S, K‐P, and K‐N interactions were positive while the Mg‐S, Mg‐P, and Mg‐N interactions were negative; the elemental composition was affected to a considerable extent by various interactions as well as by the first order effects of the elements involved.
Surface Area Determination of Soils by Adsorption of Ethylene Glycol Vapor
Authors: Morin R. E. , Jacobs H. S. 
Published: July 2010

AbstractSurface area was determined from ethylene glycol (EG) retained by vapor‐wetted soils and clays in equilibrium with EG‐bentonite or ‐resin buffers. The method compared favorably with previously proposed equilibrium and nonequilibrium methods.Only small excesses of EG are adsorbed by vapor‐wetted samples. This reduces equilibration time, extends buffer life, and eliminates hysteresis on the drying curve at the monolayer point. The determination is independent of sample size; moderate temperature fluctuations; or moisture present in EG, buffer, or sample. Use of redistilled EG is not necessary.The monolayer end point can be determined using a series of EG‐bentonite buffers independently of other methods. Buffers containing more than a monolayer of EG can be used if suitable corrections are made.
Formation of Clay Mineral‐Rhizobial Polysaccharide Gels and Their Measurement by Torque Viscometry
Authors: Davis R. J. , Heald W. R. 
Published: July 2010

AbstractThe gel‐forming characteristics of several Rhizobial polysaccharides and clay mixtures were studied using a torque‐type viscometer. This method was found to be both a rapid and a precise measure of the total effect of the added compound to clay than was the floc volume. Krillium and dextran were used as comparison compounds. Krillium greatly influenced the viscosity of clay suspensions, but dextran had no effect. All rhizobial poly‐saccharides used had some effect on the properties measured, and most compared favorably with Krillium.
Beta Oxidation of Phenoxyalkanoic Acids in Soil
Authors: Gutenmann W. H. , Loos M. A. , Alexander M. , Lisk D. J. 
Published: July 2010

AbstractThe 2,4‐dichlorophenoxyalkanoic acids with aliphatic moieties ranging from butyric to undecanoic were metabolized by the soil microflora to acids of shorter chain length. Phenoxyalkanoic acids with an even number of carbons in the fatty acids consistently were converted to products with an even number of carbons while compounds with an odd number of carbons in the aliphatic moieties were converted to the corresponding 2,4‐dichlorophenoxyvalerate, propionate, and ultimately 2,4‐dichlorophenol as measured by gas chromatography. The results demonstrate a beta oxidation sequence in the degradation of these pesticides in soil.
The Effects of Soil Temperature and Form and Level of Nitrogen on Growth and Chemical Composition of Italian Ryegrass
Authors: Nielsen K. F. , Cunningham R. K. 
Published: July 2010

AbstractItalian ryegrass was grown in a clay loam soil in a greenhouse at 3 soil temperatures 11°, 19.5° and 28°C. with 6 levels of N (0 to 500 ppm.) as NH4+ (treated with “N serve”) or NO3‐. Tops grew best at 19.5° and roots at 11°C. At 19.5° yields of tops with NO3‐N were maximal at 100 ppm. and with NH4‐N at 200 ppm. Increasing NO3‐N above 100 ppm. greatly decreased yields of tops, but increasing NH4‐N did not. Yields of tops were larger with NO3‐N than with NH4‐N at low levels of N but were smaller at higher levels.Root weights were similar with both forms of N, but whereas the roots were well distributed throughout the soil with NH4‐N, with NO3‐N, they were mainly confined to the top half of the soil.Form of N greatly influenced the composition of the grass. Increasing NO3‐N decreased the concentrations of P, Cl and S, and NH4‐N decreased the concentrations of Ca. Percent N was larger with NO3‐N than with NH4‐N.Raising the soil temperature greatly increased % Ca and % Mg but had little influence on concentrations of N, P, S, Na, and K. Percent Cl was always largest at 11°C.
Evaluating the Sulfur Status of Soils by Plant and Soil Tests
Authors: Fox R. L. , Olson R. A. , Rhoades H. F. 
Published: July 2010

AbstractSeveral methods for evaluating the sulfur status of soils were compared. Among chemical procedures used, water and phosphate extractions gave the best agreement with sulfur A values and total sulfur uptake by alfalfa from Nebraska soils. Water was an inefficient extractant of sulfate from a Hawaiian Latosol. Calcium phosphate solution was a more convenient extractant than KH2PO4 for both Nebraska and Hawaii soils.
Evaporation from Soil Shrinkage Cracks
Authors: Adams John E. , Hanks R. J. 
Published: July 2010

AbstractField and laboratory studies have shown that evaporation from shriukage cracks may equal or exceed that from surface soil. Evaporation from moist soil samples (soil atmometers), suspended at various depths in naturally occurring shrinkage cracks in Houston Black clay, was determined. During the first 19 hours, the moisture evaporated at the 24‐inch depth was 55% of that evaporated at the surface. Soil atmometers suspended at depths of 12 inches or less were reduced from 55% soil moisture to < 17% in 44 hours. Crop cover affects evaporation in shrinkage cracks. Atmometers at the 12‐inch depth in grain sorghum lost half as much water as atmometers at the same depth in corn or permanent pasture. Field measurements showed from 2.9 to 4.6 times more surface area exposed on the shrinkage crack walls than as surface soil per square yard.Laboratory studies indicate that evaporation from the side walls of shallow shrinkage cracks may vary from 35 to 91% of that from a comparable area of surface soil depending on soil moisture content. Wind tunnel studies with a simulated shrinkage crack 20 inches deep showed that evaporation increased at all depths as surface wind velocity increased. Increasing the wind velocity from calm to 25 mph. increased evaporation 570% at 2 inches below the surface and 100% at 18 inches. Evaporation increased as crack width decreased from 2.75 inches to 1.75 inches.