bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solubility‐Temperature Effect on the Adsorption of Gamma‐ and Beta‐BHC from Aqueous and Hexane Solutions by Soil Materials
Authors: Mills A. C. , Biggar J. W. 
Published: July 2010

AbstractFreundlich adsorption isotherms were obtained for gamma‐ and beta‐isomers of 1,2,3,4,5,6‐hexachlorocyclohexane adsorbed from aqueous and hexane solvents on Ca‐Staten peaty muck, Ca‐bentonite Ca‐Venado clay, and silica gel in the temperature range of 10 to 40C. Comparison of normal and “corrected” isotherms revealed a significant effect on adsorption due to the influence of temperature on solubility. The 1/n constants of the Freundlich equation increased with temperature according to the theory of dilute solutions. When the solubility effect is removed, the gamma isomer has greater adsorbability than the beta isomer, possibly because the former possesses a dipole moment whereas the latter does not. At constant solution fugacities, the gamma isomer on Staten peaty muck competed somewhat more effectively with hexane than with water.
Equilibrium Constants between both Freshly Prepared and Aged H Montmorillonites and Chloride Salt Solutions
Authors: Foscolos A. E. , Barshad I. 
Published: July 2010

AbstractFreshly prepared and aged H montmorillonites were equilibrated with NaCl, KCl, MgCl2, and CaCl2 solutions of low concentrations. With freshly prepared H montmorillonites equilibrium constants were obtained. With aged H montmorillonites equilibrium constants were not obtained because the 1N KCl extracting technique did not yield the correct amount of adsorbed H+. To overcome this, a new method for determining adsorbed H+ was used. However, the measured equilibrium constants were either smaller or contradictory to those obtained with freshly prepared H montmorillonites because it was not possible to assess the exact amount of adsorbed H+ in the presence of hydroxyaluminum compounds. Thus, only equilibrium constants obtained with freshly prepared H montmorillonites were considered to be valid.
Arsenic Content of Soil and Crops Following Use of Methanearsonate Herbicides
Authors: Johnson L. R. , Hiltbold A. E. 
Published: July 2010

AbstractDistribution of As with depth in soil was determined after 4 years of repeated applications of monosodium (MSMA), monoammonium (MAMA), and disodium methanearsonate (DSMA) to turf. Arsenic concentrations decreased with depth. Percentage recovery of applied As in the upper 30 cm of soil decreased with increasing application rates. Yields of cotton (Gossypium hirsutum L.), soybeans (Glycine max L. Merr.), sorghum‐sudan hybrid (Sorghum vulgare Pers. × S. sudanense (Piper) Stapf), corn (Zea mays L.), oats (Avena sativa L.), vetch (Vicia villosa Roth), and crimson clover (Trifolium incarnatum L.) were not affected by previous As treatments. Seed of cotton and soybeans accumulated more As than corn or forage from sorghum or the winter crops. Uptake of residual As was greater from MSMA than from DSMA or MAMA, and from the high rate of application than from the medium or low rates. About 90% of the soil As content occurred in the clay fraction. Much of the soil As was extracted by NH4Cl that removed little if any P. Most of the soil P was associated with iron minerals and organic matter, while As was associated with aluminum. No appreciable organic As was found.
Lanthanum and Scandium Distribution in Three Glacial Soils of Western Wisconsin
Authors: Kline J. R. , Foss J. E. , Brar S. S. 
Published: July 2010

AbstractNeutron activation analysis was used to deterimne the total La and Sc content of three soils developed from loess‐capped glacial till. The profiles were classified as Gray‐Brown Podzolics (Hapludalfs) overlying paleosols developed in Rockain till. The total La content in the less than 250µ fraction of these soils ranged from 18.1 to 37.1 ppm, with an average content of 23.7 ppm in the loess and 28.5 ppm in the glacial till. Total Sc in the soils ranged from 5.1 to 10.9 ppm with average contents of 6.5 and 9.0 ppm in the loess and glacial till, respectively. Translocation by pedogenic processes was indicated by the accumulation of these elements in the argillic B horizons. Correlation coefficients of La and Sc with clay percentages in the profiles were 0.79 and 0.88, respectively.
Effect of Phosphorus Carriers and Zine Sources on Phosphorus‐Zine Interaction in Corn
Authors: Ganiron R. B. , Adriano D. C. , Paulsen G. M. , Murphy L. S. 
Published: July 2010

AbstractGrowth of corn (Zea mays L.) seedlings in solution cultures responded to temperature > Zn rate > P carrier > Zn source. Phosphorus accumulated in roots and shoots of Zn‐deficient seedlings at the higher temperature, but was depleted from roots when seedlings were supplied with Zn. Nearly similar Zn concentrations were usually present in roots and shoots of seedlings grown at the lower temperature, suggesting that temperature affected soil Zn availability more than uptake or translocation. Monoammonium phosphate (MAP) was slightly more favorable for growth than ammonium polyphosphate (APP), but APP increased P uptake more than MAP. Chelated Zn was a slightly more efficient source than Zn sulfate.Phosphorus depressed corn grain yields when soil Zn levels were low. Applying Zn increased grain yields only to levels produced without P fertilization. Concentrations of P in the leaves varied inversely with the rate of Zn fertilization, but concentrations of Zn were not affected markedly by the treatments. APP and chelated Zn were only slightly better sources than MAP and Zn sulfate, respectively.
Steady Gravitational Convection Induced by a Line Source of Salt in a Soil
Authors: Raats P. A. C. 
Published: July 2010

AbstractA theoretical analysis of steady gravitational convection from a line source of salt in a saturated or in a uniformly partially saturated soil is presented. The flow pattern of the water‐solute mixture and the distribution of the salt are shown to depend upon the source strength of the line source, the effective mass diffusion coefficient of the salt in the soil, the hydraulic conductivity of the soil, and a parameter describing the increase in density due to the added solute. Qualitatively, the analysis agrees with experimental observations. Theory and experiment both indicate that gravitational convection can be significant only if the hydraulic conductivity is large, which may be the case if the soil is coarse textured and the water content is not too small.
Influence of Chemical Weathering on Basal Spacings of Clay Minerals
Authors: Conyers E. S. , Wilding L. P. , McLean E. O. 
Published: July 2010

AbstractIllite, vermiculite, montmorillonite, kaolinite, and a Brookston soil clay were weathered by H‐, HO‐, and H‐resin; sodium tetraphenyl‐boron + resin; and boiling 1N nitric acid + resin treatments. X‐ray diffractograms of the treated clays suggest the following effects on the mineral structures. Resin caused relatively minor changes compared to unweathered specimens. NaBPh4 removed interlayer K from 10A and 10–14A interstratified components of illite, vermiculite, and Brookston soil clay resulting in partial expansion of 10–14A components as evidenced by diffractograms of glycolated samples. HNO3 dissolved less stable components of the illite specimen and/or favored preferred orientation of aggregates as indicated by marked increases in the intensity of mica basal reflections. Estimations of K content of mica from 10:5A peak‐intensity and area ratios indicated that mica remnants in acid‐treated illite were lower in K than those in unweathered or NaBPh4‐treated illite. Treatment with HNO3 severely altered the expansibility of vermiculite, transforming a part of the specimen into an expanding lattice structure and dissolving much of the remainder. The 10A and 14A components of Brookston soil clay were less altered by HNO3 treatment; however, the 17–18A peak in the glycolated sample was sharper, and thermally stable interlayer components were less evident after acid treatment. HNO3‐ and NaBPh4‐treated kaolinite and montmorillonite basal spacings remained essentially the same as untreated samples. These data are evaluated in terms of mechanisms of K‐release from the weathered clays and subsequent K‐content found in soybean plants (Glycine max L.) grown in the clay residues.
On the Interaction of Water Molecules and Montmorillonite Surfaces
Authors: Kijne J. W. 
Published: July 2010

AbstractThe adsorption of water was studied on monoionic montmorillonite saturated with Cs, Rb, Li, Na, NH4, and Ca ions. These ions vary in their influence on the structure of water in solution. Thus the effect on the adsorbed water by exchange ions could be compared with the effect of these ions in solution. Heats of wetting of the montmorillonite samples were determined as a function of the equilibrium relative vapor pressure. Entropy values were calculated from the heats of wetting combined with values of the surface potential from adsorption isotherms using the Gibbs surface excess equation. The decrease in heats of wetting with increasing relative vapor pressure was discontinuous near p/po = 0.1. This was interpreted as indicating a change at the surface of the clay mineral probably related with ion hydration effects. Consequently the obtained entropy changes could not be assigned entirely to the adsorbed water molecules. At low relative vapor pressures the entropy values strongly reflected the influence of the exchange ion which was found to be similar to that exerted by these ions in solution. At higher relative vapor pressures the entropy of the system was about 4 e.u. below that of liquid water which was nearly the same as the likely value for the silicate sheet itself obtained in earlier studies.
Weathering of Montmorillonite During Formation of a Solodic Soil II. Nature of the Mixed Layer Products
Authors: Klages M. G. 
Published: July 2010

AbstractThe Solodic (Paleargid) soil being studied had previously been shown to have clay mineralogy similar to that of associated Chestnut (Argiustol) and Solodized‐Solonetz (Natrargid) soils. Mica and montmorillonite were the dominant clay minerals in the calcareous glacial till parent material. Montmorillonite failed to give an X‐ray diffraction peak in clays of the surface soil, yet infrared absorption, cation exchange capacity, and surface area were similar to that of the parent material. Clays of the parent material (C horizon) and surface soil (A horizon) were studied to determine mineralogical properties. Dioctahedral and trioctahedral minerals were present in both the A and C horizon with dioctahedral predominating. Quantitative estimates of mineral composition were made on the basis of infrared absorption, total potassium, and cation exchange properties. These showed kaolinite, quartz, chlorite, vermiculite, and allophane to be present in addition to mica and montmorillonite. Differences in clay mineral content from the parent material to the surface soil were minor. It was concluded that the most important effect of soil formation on clay mineralogy was a change from relatively pure mineral crystals to particles with several 2:1 minerals in a highly random arrangement of various degrees of interlayer expansion.
Kinetics of the Formation and Breakdown of Ca‐Montmorillonite Tactoids
Authors: Shainberg I. , Kaiserman A. 
Published: July 2010

AbstractThe kinetics of Ca‐montmorillonite tactoid formation and breakdown was followed by recording the changes in light transmission as a function of time when Ca‐montmorillonite suspensions of 0.05% (w/v) concentration were added to Na‐montmorillonite suspensions of the same concentration in a titrating vessel placed in the light path of a spectrophotometer. Tactoid formation was found to be instantaneous whereas the breakdown of Ca tactoids took about 10 min. It was suggested that the initial step upon mixing sodium and calcium montmorillonite was the redistribution of adsorbed ions. For tactoids to break, ions have to interdiffuse into the tactoids. Since the mobility of ions adsorbed on the internal surfaces is low, tactoid breakdown is slow. Ion diffusion on the single platelets of Na clay and the external surfaces of the tactoids is high; thus the formation of tactoids is instantaneous.
The Prediction of Evaporation, Drainage, and Soil Water Storage for a Bare Soil
Authors: Black T. A. , Gardner W. R. , Thurtell G. W. 
Published: July 2010

AbstractEvaporation, drainage, and changes in storage for a bare Plainfield sand were measured with a lysimeter during June, July, and August 1967, under natural rainfall conditions. Cumulative evaporation at any stage was proportional to the square root of time following each heavy rainfall. The drainage rate was found to be an exponential function of water storage. Both relations can be predicted from flow theory with knowledge of soil capillary conductivity, diffusivity, and moisture retention characteristics. Using these two relations and daily rainfall data, the water storage in the top 150 cm was predicted over the season to within 0.3 cm.
Standard Heats and Entropies of Exchange for Alkali Metal Cations on Wyoming Bentonite
Authors: Gast R. G. , Van Bladel Robert , Deshpande K. B. 
Published: July 2010

AbstractStandard heats of exchange, ΔH°, were determined for alkali metal cation exchange on Wyoming bentonite using a Calvet microcalorimeter. In addition, values of ΔH° for Na‐Cs, Na‐Rb, and Cs‐Rb exchange were evaluated from selectivity measurements conducted at 25 and 50C. Standard entropies of exchange, ΔS°, were calculated by combining the standard heats with free energy values, ΔG°, estimated from equilibrium selectivity coefficient determinations using the relationship ΔG° = ΔH° − TΔS°. Values of ΔH° varied from +150 cal mole‐1 for Na→Li exchange to −2,557 cal mole‐1 for Na→Cs exchange. Values of ΔG° ranged from +48 to −1,081 cal mole‐1 for these reactions giving values of ΔS° ranging from +0.5 to −4.9 cal mole‐1 deg.‐1. Both ΔH° and ΔS° were always negative for uptake of the preferred cation with the absolute values increasing with the degree of selectivity. While the entropy changes did contribute significantly to the standard free energies of exchange, they were only about 10% of the hydration entropy differences for Na‐Li and Na‐K exchange and 26 and 41% for Na‐Rb and Na‐Cs exchange, respectively.
Theoretical Consideration of the Calcium Sulfate‐Bicarbonate‐Carbonate Interrelation in Soil Solution
Authors: Nakayama F. S. 
Published: July 2010

AbstractThe probable distributions of the ion‐pairs CaSO4° and CaCO3°, and complex CaHCO3+ in solution are discussed thermodynamically and graphically in terms of SO42‐, CO32‐, HCO3‐, and H+ activities. In alkali media where the CO32‐ form predominates, the CaCO3° species will dominate the CaSO4° and CaHCO3+ forms and is a significant part of the total calcium in solution.
Adsorption of Nitrate in Amorphous and Kaolinitic Hawaiian Soils
Authors: Singh B. R. , Kanehiro Y. 
Published: July 2010

AbstractThe adsorption of nitrate in an amorphous Akaka silty clay and kaolinitic Wahiawa silty clay increased consistently with increasing concentration and decreasing pH of the electrolyte solution. The magnitude of adsorption was higher in the Akaka than in the Wahiawa soil. The amount of adsorbed nitrate was notably more when SO43 rather than Cl was used as the replacing anion. It was deduced that while the concentration‐dependent NO3 adsorption is due to electrostatic and van der Waal forces, the pH‐dependent adsorption is largely due to electrostatic forces. The adsorption of nitrate followed the Freundlich type of isotherm.
Ion Selectivity of Micas as Influenced by Degree of Potassium Depletion
Authors: Le Roux J. , Rich C. I. 
Published: July 2010

AbstractThe Rb/Sr selectivity coefficient of muscovite and biotite reached a maximum at an intermediate degree of K‐depletion of these micas. The Rb/Sr ratio of ions absorbed from a solution, initially containing equivalent amounts of Rb and Sr, was determined for the two micas altered to different degrees to Mg‐vermiculite. X‐ray diffraction of the Rb‐Sr treated vermiculites gave nonintegral peaks for the basal reflections, indicating random interstratification of Rb and Sr + Mg saturated layers. The results support previous proposals that selective sites for K are probably situated at wedge‐shaped zones occurring at frayed edges and deeper within the altered mica particles. As K is removed from mica, the number of such wedges should first increase and then decrease. Selectivity of K and other large monovalent ions should also follow this same trend.
Reduction of Sulfate to Sulfide in Waterlogged Soil
Authors: Connell W. E. , Patrick W. H. 
Published: July 2010

AbstractA study was made of sulfate reduction to sulfide in water‐logged soils supplied with an energy source. Sulfate reduction was more rapid in surface soil than in subsurface layers with sulfide appearing 2 days after waterlogging samples of a surface soil. The amount of sulfide precipitated from added H2S in two soils was approximately equivalent to the amounts of ferrous iron released by waterlogging. Added Fe2O3 was effective in precipitating H2S. Sulfate reduction was retarded by nitrate. Addition of oxygen to highly reduced soils caused a rapid decrease in sulfide content, with one‐half of the sulfide being oxidized in 15 minutes and all the sulfide oxidized after 8 hours.
Fragipan Horizons and Be Masses in the Middle Coastal Plain of North Central North Carolina
Authors: Steele Forrest , Daniels R. B. , Gamble E. E. , Nelson L. A. 
Published: July 2010

AbstractSoils with fragipan horizons are minor in areal extent but soils with friable eluviated (Be) masses are common along the 120‐ and 140‐foot contours (37‐ to 43‐m) of the Sunderland geomorphic surface between Goldsboro, N. C., and Emporia, Va. Where they occur, fragipan horizons commonly have Be masses, and in some the dense brittle materials and friable eluviated materials are intimately mixed. The morphology of fragipan horizons and horizons with Be masses are similar and it is difficult to separate them where they merge on the landscape. Brittleness is about the only feature that can be used consistently to separate fragipan horizons and horizons with Be masses. Brittleness that is produced by partial iron cementation, plinthite for example, should not be used in identification of fragipan horizons.
Properties of Some Soils in the Cumberland Plateau as Related to Slope Aspect and Position
Authors: Franzmeier D. P. , Pedersen E. J. , Longwell T. J. , Byrne J. G. , Losche C. K. 
Published: July 2010

AbstractSoils developed from acid siltstones and shales were sampled on the lower, middle, and upper part of steep north and south‐facing slopes in transects made across ridges in eastern Kentucky and Tennessee. Particle size distribution, base saturation, and soil temperature are related to slope position. Soils in the middle slope positions are higher in coarse material than those in the upper or lower positions. Soils in the lower slope positions have the highest base status and are coolest.Slope aspect influences soil temperature and organic matter content and the kinds of horizons formed and their color. Most soils on the south‐facing slopes have argillic horizons while most on the north‐facing slopes have cambic horizons. Soils on the north slope have almost 2C lower mean annual temperature, contain more organic matter, are darker in color, and hold more water during a period of water stress than soils on the south‐facing slope.
Runoff Inducement in an Arid Region by Removal of Vegetation
Authors: Tadmor N. H. , Shanan L. 
Published: July 2010

AbstractEradication of natural vegetation from runoff plots in a 250‐mm isohet region increased annual runoff threefold from 7% to 21% of annual rainfall. The vegetation cover increased the infiltration rates of the loess soil by 40–50%. A “priming” rainfall of 2–4 mm/day was required to cause runoff from both bare and vegetation areas. Interception storage of vegetation was 0.1–0.4 mm.
Effect of Soil Temperature on Nodulation of Ceanothus Velutinus Dougl.
Authors: Wollum A. G. , Youngberg C. T. 
Published: July 2010

AbstractThe nodulation of snowbrush (Ceanothus velutinus Dougl.) from two seed sources was evaluated at soil temperatures of 10, 15, 22, 26, and 31C. One source was from the east side of the Cascade Mountains in Oregon and one from the west side. Plants in these areas are considered distinct ecotypes. For the east ecotype it was found that more and larger nodules were formed at 26C than at any other temperature tested. However, the number and size of nodules for the west ecotype plants were not significantly different at 22 and 26C. Maximum plant yields for the east and west plants were found to occur at 26 and at 22 and 26C, respectively. Generally, the east ecotype plant required a longer period of time to form nodules than the west plants at comparable temperatures. When the natural variation of soil temperature was characterized, it was found that temperatures were below 20C about 80% of the sampling period and between 20 and 25C for less than 10% of the sampling period.
Numerical Method for Estimating Simultaneous Flow of Water and Salt in Unsaturated Soils
Authors: Bresler E. , Hanks R. J. 
Published: July 2010

AbstractA numerical solution of non‐interacting salt flow simultaneously with water in unsaturated soil was devised and programmed. Solutions were obtained for infiltration, redistribution, and evaporation under different wetting and boundary conditions. The effect of diffusion on salt distribution was neglected in the computations. The method was found to give reasonable results for non‐interacting solutes. When compared with measured total salt distribution after one wetting and drying cycle, the model gave fairly good results when a source term was added to the computations. The method can be applied to some practical problems, such as leaching of salts and fertilizer movement.
Infiltration, Redistribution, and Subsequent Evaporation of Water from Soil as Affected by Wetting Rate and Hysteresis
Authors: Bresler E. , Kemper W. D. , Hanks R. J. 
Published: July 2010

AbstractSoil columns were wetted at three different rates which caused unequal water content profiles during infiltration. Water content profiles during infiltration, redistribution, and evaporation were observed experimentally and computed using a numerical solution of the isothermal flow equation. Each wetting rate resulted in a different drying water retention curve. The hysteresis in soil water content‐water suction relationships had a larger influence as the wetting rate increased. Hysteresis effects tend to keep the water content higher and the zone of wetting shallower during the redistribution stage when rates of wetting are faster. Higher water content and lower wetting depth at any redistribution time caused subsequent evaporation to be greater. Evaporation was directly related to the previous wetting rate, either when the soil was subjected to evaporation immediately following infiltration or when subjected to evaporation after redistribution for 4 days. The differences in evaporation between the three wetting treatments were significant at the 99% probability level. Allowing time for redistribution decreased evaporation compared to evaporation and redistribution occurring simultaneously. The effects of wetting rates and hysteresis on water content profiles and evaporation were similar in the experimental and computed results.