bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Soil Conditioners on Infiltration and Water Movement in Soils
Authors: Kijne J. W. 
Published: July 2010

AbstractThe infiltration of water at 2mbar suction into horizontal columns of two soil materials of different textures was studied. The columns had been treated with two soil conditioners, Krilium and poly(vinyl alcohol). The soil‐water diffusivities were calculated from the water content distribution data. Treatment of a clay loam with the soil conditioners caused 1.5‐fold to 3‐fold increases in soil‐water diffusivity over the whole range of volumetric water contents. When expressed as a function of soil water potential, soil‐water diffusivity increased by this treatment more than 10‐fold at the lower soil‐water potentials. The same treatment had far less effect on the soil‐water diffusivity of a loamy sand. For both soils the rate of movement of the wetting front increased as a result of treatment with the soil conditioners.The calculated mean diffusivity and rate of movement of the wetting front in these soils was greater for n‐heptane than for water. The intrinsic diffusivity and penetrability differed for the two permeants. Changes in viscosity, surface tension, and apparent contact angle did not account fully for this dependence of diffusivity and penetrability on the permeating liquid.
Determination of Clay Surface Acidity by Infrared Spectroscopy
Authors: Harter Robert D. , Ahlrichs James L. 
Published: July 2010

AbstractA new and simple method for estimating pH at the surface of colloidal particles has been devised. By use of infrared spectroscopy the effect that proximity to a colloidal surface has on an organic acid molecule can be ascertained. An intensity ratio of the carboxylate to carbonyl infrared absorption bands (1,550 to 1,610 cm‐1 and 1,690 to 1,760 cm‐1, respectively) of organic acids can be used as an indicator of hydrogen ion activity in the compound's environment. Benzoic acid seems to be the best choice for this type of study, since it is not adsorbed by the clay surface in the presence of water. The surface of Wyoming bentonite seems to be about 100 times more acid than the solution at a pH of about 7.0. As the pH decreases, there is a decreasing difference between surface and solution pH.
Factors Affecting Urea Hydrolysis and Ammonia Volatilization in Soil
Authors: Overrein L. N. , Moe P. G. 
Published: July 2010

AbstractLaboratory incubation experiments were conducted to determine the effect of rate and depth of urea application and the rate of soil aeration on rates of urea hydrolysis and ammonia volatilization occurring with soils taken from the surface horizons of Chalmers silt loam and Plainfield sand.Measurements were also made of the effect of urea hydrolysis on the pH of undisturbed soil in the immediate zone of urea application. The rate of urea hydrolysis was shown to be directly proportional to the rate of urea application when soils were incubated at 28C. Ammonia volatilization rates increased at an exponential rate as rates of urea application were increased. This resulted in a larger proportion of the added urea nitrogen being lost from the soil through ammonia volatilization at the higher rates of urea application. Ammonia volatilization rates were inversely proportional to the depth of urea application and decreased more rapidly with depth in wet soil than in moist soil. The pH of Chalmers soil in the zone of urea application attained a maximum pH of 8.8 with both 224 and 896 kg/ha (200 and 800 lb/acre) applications of urea nitrogen. Soils receiving a heavy surface application of urea maintained a high pH throughout a 4‐week incubation period. Soil aeration rate had no significant effect on rates of urea hydrolysis, but ammonia volatilization rates increased as the gas exchange rate in the soil increased.
Water Consumpton by Phaseolus Vulgaris and Zea Mays as Influenced by Manganese Fertilization
Authors: Kozakiewicz Aleksander , Ellis B. G. 
Published: July 2010

AbstractIn a greenhouse experiment using a Houghton muck soi fertilization with Mn, either with or without liming, increased the efficiency of water utilization by both pea beans (Phaseolus vulgarus) and corn (Zea mays). Where the deficiency was mild (14% increase in dry weight due to use of Mn), the larger Mn treated pea bean plants used less total water in 35 days than did smaller untreated plants.
Salt Displacement of Acid‐Treated Trioctahedral Vermiculites
Authors: Kaddah Malek T. , Coleman N. T. 
Published: July 2010

AbstractFreshly prepared and 30‐day‐aged samples of HCl‐treated trioctahedral vermiculites from Libby, Montana (L) and northeastern Transvaal, South Africa (S) were leached with 1N or more dilute solutions of NaCl, KCl, CaCl2, or MgCl2. The exchange acidity, exchangeable H3O, Al, and Mg, and the cation‐exchange capacity after acid‐salt treatment were determined.With both the L and S minerals, the sum of the salt‐displaceable ions after acid treatment corresponded to approximately 90% of the initial CEC. For freshly acidified materials, the exchange acidity (consisting of displaced H3O and Al ions) comprised the bulk of the exchangeable ions. After 30 days of aging in water at room temperature, exchange acidity had decreased by around one‐half, and equivalent amounts of exchangeable Mg had appeared.The most striking findings concerned: (i) differences between the two minerals with regard to the amounts of H3O and Al displaced by salts, and (ii) differences in displaced H3O and Al depending on the exchanging cation and the concentration of the displacing solution. The exchange acidity from fresh HCl‐treated S vermiculite consisted of about 60% H3O and 40% Al when 1N NaCl, CaCl2, or MgCl2 was the displacing salt. For L vermiculite, titratable acidity displaced by 1N NaCl, CaCl2, or MgCl2 was around three‐fourths Al. For both minerals, exchange acidity measured with 1N or 0.05N KCl, 0.05N NaCl, or 0.02N CaCl2 or MgCl2 was almost entirely H3O.X‐ray patterns of K‐saturated, acidified samples showed interlayer deposits and reduced collapsibility when the samples were leached with KCl. There were virtually no indications of interlayer material when the samples were leached with 1N CaCl2 before KCl.
Determination of Organic Carbon and Carbonates in Soils
Authors: Anderson J. U. , Harris W. 
Published: July 2010

AbstractProcedure and apparatus for determining organic and inorganic carbon in soils are described. The digestion acids used differ from those used in common practice in containing no H2SO4.Sulfate interference was shown to prevent complete digestion of carbonates in a system containing H2SO4.The procedure described is accurate for carbonates and for organic compounds as difficult to oxidize as benzoic acid. The time required for one determination of organic carbon is 30 min; that for inorganic carbon is 22 min.
A Simple Technique for Preparing and Maintaining Sterile Soils for Plant Studies
Authors: Bartlett R. J. , Zelazny L. W. 
Published: July 2010

AbstractThe proposed method depends upon the antimycotic activity of propylene oxide and the permeability of polyethylene. Inside a warmed pressure cooker, the epoxide diffuses rapidly through a plastic bag, sterilizing the moist soil contained. Release of pressure reverses diffusion. Detoxication is completed under vacuum at 45C. The bag then serves as a chamber for the storage of sterile soil or for the sterile culture of plants.
Thermal Properties of a Pumice Soil
Authors: Cochran P. H. , Boersma L. , Youngberg C. T. 
Published: July 2010

AbstractDacite pumice materials deposited by the eruption of Mount Mazama cover a land area for as much as 161 km (100 miles) north and east of Crater Lake, Oregon. Frequent night frosts occur in this region. Thermal properties of the pumice material were investigated to determine their affect on the occurrence of low temperatures in the area and thus gain a better understanding of the factors governing the distribution of lodgepole (Pinus contorta Dougl.) and ponderosa pine (Pinus ponderosa Laws). Thermal conductivities were determined experimentally with a line heat source and calculated theoretically. The theoretical calculations were based on methods which take into account the volume fractions of solid, air, and water of the pumice and the thermal conductivity of each one of these components. The thermal conductivities of dacite pumice were found to be very low, which may account for the frequent occurrence of night frost in this region.
Cation Exchange Capacity Variations with pH in Soil Clays
Authors: de Villiers J. M. , Jackson M. L. 
Published: July 2010

AbstractSoil clays containing pedogenically chloritized 2:1 layer silicates, after brief contact at 25C with 2% Na2CO3 (pH 11), developed a proportionately large increment of CEC which was retained after thorough washing with neutral salts (KCl, NaCl) to reduce the pH value below 7. A soil clay from Natal, S. Africa showed the largest increase—from 2.4 meq/100 g at pH 5 to 8.0 meq/100 g after alkaline and KCl treatments. This CEC hysteresis or delta value largely disappeared when washing with a NaOAc buffer of pH 5 followed the alkaline treatment. Similar effects were absent from specimen kaolinite, montmorillonite, and vermiculite. The presence of aluminous, pedogenic chlorite was shown, by X‐ray and analytical investigation, to be a common property of the soil clays exhibiting pH dependent CEC. This finding is supported by separate studies on synthetic aluminous chlorite, which showed variable CEC properties essentially identical to those of these soil clays. Release of the initially blocked isomorphous substitutional negative charge by deprotonation of the positive hydroxy alumina in aluminated soils, clays and allophane is the indicated mechanism accounting for pH dependent, hysteretic CEC charge of the mineral portion of soils.
Changes in Exchangeable Potassium Observed on Drying Soils after Treatment with Organic Compounds: II. Reversion
Authors: Scott A. D. , Bates T. E. 
Published: July 2010

AbstractUndried samples of Marshall subsoil that contained 27 ppm exchangeable (NH4OAc extractable) K were dried to release K and then treated in various ways to maximize K reversion. This was done to determine the possibility of reducing the exchangeable K in dried soil to the level of the undried soil and, thus, of using dry samples with released K to estimate the amount of exchangeable K that was present in the soil before drying.Much of the desired K reversion was attained by simply rewetting the dry soil. The rate and amount of this decrease in exchangeable K was enhanced by heating the rewet soil, but even so, the minimum values attained with rewet samples of air‐dry and oven‐dry soil were 54 and 62 ppm K, respectively. For complete reversion, it was necessary to mix the rewet soil with organic compounds and then oven‐dry the mixture.A decrease in exchangeable K was attained by drying the rewet soil, provided organic additives were present to prevent a release of K. Thus, the effects observed with various organic additives varied with the degree to which the additives were retained in the sample while the water was removed. Additions of high‐boiling‐point, normal alcohols; rewetting with a minimum of water; and slow drying gave the best results. When 10‐g samples of oven‐dry soil with 210 ppm exchangeable K were rewet with 7 ml of water, mixed with 7 ml of octanol and dried at 110C for 48 hours in a gravity‐draft oven, there was only 30 ppm exchangeable K present. Oven drying did not enhance K reversion when sucrose or glycerol was present.
Density Errors for Soltrol‐Tygon Systems
Authors: King L. G. 
Published: July 2010

AbstractSeveral investigators have used Soltrol as a liquid for laboratory studies of flow through porous media. It is shown in this note that Soltrol can react with Tygon and possibly other flexible plastic tubing by dissolving the plasticizers from the tubing walls. This reaction increases the density of the Soltrol by as much as 2 to 4% and may cause significant errors in data being collected.
The Method of Mehta et al. Modified for Determination of Organic Phosphorus in Soils High in Extractable Iron
Authors: Bornemisza E. , Vieira L. S. , Igue K. 
Published: July 2010

AbstractA modification is proposed for the Mehta et al. organic phosphorus determination for soils high in free iron where a strong interference by the dissolved iron occurs in the colorimetric determination of total and inorganic phosphorus. This interference can be eliminated by passing the extracts through a strong acid cation exchange resin which removes the interfering ions.
Determination of Magnesium in HCl Solutions of HF‐HClO4 Digests of Soil Clays by Atomic Absorption Spectroscopy
Authors: Protz R. , DeKalb E. , Riecken F. F. 
Published: July 2010

AbstractInterferences to the determination of Mg in HCl solutions of HF‐HClO4 digests of soil clays by atomic absorption spectroscopy were suppressed by 4,000 ppm Sr. Recovery of Mg added to digests ranged from 96 to 106%. Duplicate clay samples of 110 soils were taken from soil suspensions on successive days. The Mg content of these samples ranged from 0.74 to 1.61%. The mean deviation between duplicates was 0.03%, with a range of 0.00 to 0.10%. A rapid method for Mg determination in soil clays by atomic absorption spectroscopy is proposed.
Contributions of Soil Factors to Lime Requirement and Lime Requirement Tests
Authors: Pionke H. B. , Corey R. B. , Schulte E. E. 
Published: July 2010

AbstractOne hundred and twenty‐seven soils were examined for relationships existing between lime requirement and the pH‐dependent sites on organic matter and clay as well as “acidic Al.” The ranking of soil properties as predictors of the CaCO3‐equilibrated lime requirement followed the order: pH‐dependent sites on organic matter > nonexchangeable acidic Al > exchangeable Al ≥ pH‐dependent sites on clay. This relationship is defined by the following equation which accounts for 89.5% of the observed variability of lime requirement as determined by neutralization with CaCO3 to pH 6.0 in N KCl: LR (meq/100g) = 0.47 + 0.97 ΔpH(KCl) × % OM + 0.03 ΔpH(KCl) × % clay + 1.73 exchangeable Al + 0.53 non‐exchangeable acidic Al.A number of the more commonly used lime requirement tests were evaluated as predictors of the CaCO3‐equilibrated lime requirement. Of these tests, the buffer methods were found to be superior to the ΔpH × % organic matter function and base unsaturation, which in turn were decidedly superior to percent base saturation for predicting soil lime requirement. The Shoemaker, McLean, and Pratt buffer was found to be somewhat better than the Woodruff buffer for measuring lime requirement, apparently because of its greater sensitivity to “acidic Al.”
Transport in Soils: The Balance of Mass
Authors: Raats P. A. C. , Klute A. 
Published: July 2010

AbstractA treatment of transport in soils, based upon a continuum theory of mixtures, is proposed. Some of the general features of this continuum theory of mixtures and of its application to soils are discussed. A soil is regarded as a mixture of phases, e.g., an unsaturated soil is regarded as a mixture of a solid phase, an aqueous phase, and a gaseous phase. The idea of balance of mass is considered in some detail, in particular in relation to deformable soils. The integral balance of mass for a certain phase over a certain volume is formulated. From the integral balance of mass differential forms are deduced. The balance of mass for water in a deformable soil is derived. It is shown that under special circumstances this balance of mass reduces to special forms that appear in the literature.
A Comparison of Injected Anhydrous Ammonia into Bermudagrass Sod Compared to Topdressed Applications of Urea and Ammonium Nitrate
Authors: Hill W. E. , Tucker B. B. 
Published: July 2010

AbstractSoil fertility experiments, primarily concerned with the evaluation of anhydrous NH3 as a source of N for bermudagrass, Cynodon dactylon (L.), when applied with the rolling coulter‐type applicator, were conducted on Parsons silt loam and Port sandy loam soils. Two factorial treatment combinations were used. The first consisted of four rates of N applied as (NH2)2CO, NH4NO3 and anhydrous NH3. The second consisted of complete factorial combinations of four rates of N as anhydrous NH3 and three spacings of the NH3 applicator knife.In general, yields were equal for all sources and all clippings at lower rates of N application. At the higher rates of N application, anhydrous NH3 produced lower yields in the first clipping and higher yields in succeeding clippings. This lag in response from anhydrous NH3 was attributed to sod burn from escaping ammonia. Reducing the applicator knife spacing tended to increase NH3 retention, decrease the sod burn, and increase the NH3 efficiency at the high rates of N application.
Ketone Adsorption on Montmorillonite
Authors: Parfitt R. L. , Mortland M. M. 
Published: July 2010

AbstractKetone adsorption by montmorillonite was found to be greatly influenced by the nature of the exchangeable cation. Mechanisms of bonding included (i) direct ion‐dipole interaction of the carbonyl with the ion in cases where the ion had a low hydration energy or where special treatments were used to dehydrate the ion; (ii) outer sphere coordination to the metal ion by bridging through directly coordinated water molecules; (iii) formation of electrovalent bonds through proton donation by 2,4 pentanedione to the clay saturated with Al or Cu ions to form the acetylacetonates of these ions.
Soil Genesis Study of a Lithologic Discontinuity in Glacial Drift in Western Wisconsin
Authors: Foss J. E. , Rust R. H. 
Published: July 2010

AbstractA study was made of soils developed in superposed parent materials in St. Croix and Pierce counties, Wisconsin. A typical stratigraphic sequence in this area consists of: (i) post‐Cary loess, (ii) Cary till or mixed zone (14,000 years B.P.), (iii) Rockian till (30,000 years B.P.), and (iv) Paleozoic sedimentary rocks. The Cary drift is thin over much of the uplands in this area; thus, current soil profiles are developed in both the Cary and Rockian drifts. Morphological data indicate the presence of a paleosol on the Rockian till. This was substantiated by various physical, chemical, and mineralogical analyses. Characteristics of the paleosol include the accumulation of clay in the B horizon, translocated iron, and a strongly leached solum. The CaO/ZrO2 and Fe2O3/ZrO2 molar ratios of selected size fractions also indicate a weathering interval between deposition of the Cary and Rockian sediments. Clay‐mineral analyses showed variation in lithology and weathering of the drifts.
Chlorinated Insecticides in Runoff Water as Affected by Crop Rotation
Authors: Epstein E. , Grant W. J. 
Published: July 2010

AbstractThe concentration and amounts of three chlorinated insecticides were lower in runoff from a rotation system of potato (Solanum tuberosum L.), oats (Avena sativa L.), and sod, than under continuous potato cropping. Runoff samples from natural runoff plots were collected following each storm, and the amounts of DDT, endrin, and endosulfan were analyzed with a gas chromatograph.The amounts of pesticides in runoff were small compared to the amount applied. The concentrations of the insecticides in the runoff (soil‐water suspension) were generally greater than those found in the settled soil (sludge).
Determination of Silica in Citrate‐Bicarbonate‐Dithionite Extracts of Soils
Authors: Weaver R. M. , Syers J. K. , Jackson M. L. 
Published: July 2010

AbstractA procedure was developed for the determination of Si directly in citrate‐dithionite extracts of soils. The procedure, which provides for noninterference by citrate, dithionite, Fe, and P was developed for measurement of the absorbance of the reduced β‐molybdosilicic acid in the working range of 5 to 25 µg of Si in 50 ml. Interference by unoxidized dithionite was eliminated by bubbling air through the extract. The interference by citrate was prevented by an excess of molybdate; that by Fe and P by tartaric acid addition.The citrate‐dithionite treatment released, per gram of soil, 3 to 174 mg of Fe2O3, 0.8 to 42 mg of Al2O3, and 0.1 to 3.8 mg Si(OH)4. The water‐soluble silica ranged from 0 to 26 µg of Si(OH)4 per ml of solution before removal of reductantsoluble Fe2O3 and Al2O3; it increased into the range of 5 to 58 after removal. At any given pH of Henry soil (in the pH range of 4 to 7), the water‐soluble silica increased markedly as a result of previous citrate‐bicarbonate‐dithionite extraction. The release of Fe, Al, and Si that occurred with the various soils on reduction indicates a possible mechanism by which these constituents may increase sufficiently to support the well‐known formation of montmorillonite from soluble and alluviated materials moved into positions of slow drainage. These constituents in solution would also favor preservation of any montmorillonite present in soil parent materials.
Desorption of Phosphate from Kaolinite by Citrate and Bicarbonate
Authors: Nagarajah S. , Posner A. M. , Quirk J. P. 
Published: July 2010

AbstractPhosphate which cannot be desorbed from kaolinite by chloride at the same pH and ionic strength at which adsorption took place is significantly desorbed by citrate and bicarbonate.In the presence of citrate or bicarbonate, phosphate adsorption by kaolinite is reduced. The extent of reduction depends on the way in which phosphate and citrate or bicarbonate are added to the clay. Maximum reduction in phosphate adsorption occurs when phosphate and citrate or bicarbonate are added together or when phosphate is introduced after citrate or bicarbonate adsorption.These effects are attributed to the fact that mole for mole exchange between phosphate and the other anion does not occur. The reduction in phosphate adsorption results not only from competition but also from a concomitant change in charge.
Manganese Uptake Attributed to Diffusion from Soil
Authors: Halstead E. H. , Barber S. A. 
Published: July 2010

AbstractAn investigation of the rate of self‐diffusion of 54Mn in 6 soils gave apparent diffusion coefficients that varied from 0.33 × 10‐7 to 2.20 × 10‐7 cm2 sec‐1.Uptake studies with corn seedlings gave a high correlation between Mn uptake and the calculated Mn reaching the root by diffusion. Calculation of the concentration gradient necessary to satisfy the Mn uptake rate by diffusion indicated that the Mn concentration at the root surface was only reduced about 5%.
Relationship of Zinc Uptake by Corn and Sorghum to Soil Zinc Measured by Three Extractants
Authors: Wear John I. , Evans Clyde E. 
Published: July 2010

AbstractCorn (Zea mays L.) and sorghum (Sorghum vulgare Pers.) plants were grown in a controlled environmental growth chamber in 12 medium‐ to coarse‐textured soils with two levels of Zn for each soil. These levels were the native amount in each soil and with 2.5 ppm added. After 4 weeks plants were harvested and Zn concentration and total Zn uptake were measured. Each soil was extracted with three different solutions: (i) 0.05N HCl plus 0.025N H2SO4, (ii) 0.1N HCl, and (iii) 0.05N EDTA at pH 7.0. Zinc uptake by the plants was correlated with the level of soil Zn determined by each extractant. The highest correlation was obtained for corn and sorghum with extractant (i). Correlation coefficients for corn for extractants (i), (ii), and (iii) were 0.89, 0.82, and 0.62, respectively. Correlation coefficients for sorghum for extractants (i), (ii), and (iii) were 0.70, 0.63, and 0.44, respectively.