bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iron Adsorption by Montmorillonite Systems: I. Preliminary Studies
Authors: Whittig L. D. , Page A. L. 
Published: July 2010

AbstractIn the study of Fe(III) adsorption by montmorillonite systems, a number of factors which could influence the amount of Fe adsorbed were investigated. Influencing factors considered were (a) extent of anion adsorption, (b) decomposition of montmorillonite by treatment with acid‐Fe(III) solutions, and (c) H+ ion concentration of the Fe(III) solutions added.Samples of H‐montmorillonite (Wyoming Clay Spur bentonite, < 1µ diameter) were equilibrated with 0.1N solutions of Fe2(SO4)3, FeCl3, and Fe (NO3)3. Essentially the same amount of Fe(III) was adsorbed from each of the solutions used. In all cases, the amount of associated anion adsorbed was negligible. It is concluded that Fe(III) is not adsorbed as a complex ion containing sulfate, nitrate, or chloride under the conditions of this study.H‐montmorillonite was washed repeatedly with 0.1N Fe2 (SO4)3, 0.1N FeCl3, and 0.1N Fe(NO3)3. Each washing was analyzed for Si and Al. The results show a small but measurable amount of decomposition of montmorillonite.The amount of Fe adsorbed by H‐montmorillonite from 0.1N Fe(NO3)3 solutions containing increasing concentrations of HNO3 shows that Fe adsorption is affected by the H+ ion concentration of the solution used.
Effects of Aluminum on Sunflower Growth and Uptake of Boron and Calcium from Nutrient Solution
Authors: Hortenstine Charles C. , Fiskell J. G. A. 
Published: July 2010

AbstractThe effects of aluminum in solution cultures on growth of sunflower plants and uptake of boron and calcium were determined under greenhouse conditions. Measurements were made of plant height and weights of roots and tops. Total amounts of aluminum, boron, and calcium in the roots and tops were determined.Aluminum in concentrations above 4 ppm. drastically reduced heights of plants and weights of tops and roots. Increases in concentration of aluminum had no effect on amount of boron in tops or roots. There were no significant effects from aluminum on amount of calcium found in tops. However, the amount of calcium in roots decreased as concentration of aluminum in solutions increased. Aluminum accumulated in large amounts in roots of sunflower plants, but there was no increase in the aluminum contents of tops as aluminum concentration in the solutions increased.
Diffusion of Ions in Bentonite and Vermiculite
Authors: Lai T. M. , Mortland M. M. 
Published: July 2010

AbstractThe diffusion of five ions into three different homoionic bentonite gels obeyed Fick's law with the special boundary conditions for diffusion into solids. The diffusion coefficients of the ions followed the sequence SO4 > Na > Rb > Ca > Cs for all three homoionic bentonite gels. The effect of exchangeable cation on the diffusion coefficient of the diffusing ion in bentonite gels followed the sequence K > Na > Li. The effect of exchangeable cation on the activation energy and distance between successive absorption sites of the diffusing cation followed the sequence Li > Na > K. Cs ion diffused into Csvermiculite but not into Na‐vermiculite. SO4= ion mobility was higher at low clay concentrations than in pure water. As clay concentration increased, SO4= ion diffusion rate decreased more rapidly than that of exchangeable Na+ ion. The factors affecting diffusion of ions in clay gels are discussed.
Morphology and Classification of Certain Soils in East‐Central Minnesota and Northwestern Wisconsin
Authors: Erickson R. A. , Paschall A. H. 
Published: July 2010

AbstractThis is a report on investigations made of soils on the northern and eastern periphery of the Grantsburg sublobe of the Des Moines lobe (Mankato) located in east‐central Minnesota and northwestern Wisconsin. Sola of these soils are developed in Cary and post‐Cary parent materials, ranging from sandy loam to silt loam in texture. Most of the profiles are developed in silts of varying thickness overlying tills of the Cary ground moraine. Modal profile descriptions are summarized. Selected physical and chemical characteristics are presented.
Correlations between Constituents in Irrigation Waters and Irrigated Soils in Kansas
Authors: Jacobs H. S. , Naddih B. I. , Dixon R. M. 
Published: July 2010

AbstractSoil and water from 26 sites from north‐central and southwestern Kansas were studied to determine if knowledge of the chemical composition of irrigation water could be used to predict salt and Na accumulation in soil. Samples were collected in the summer of 1958 and 1959.Mean exchangeable Na percentage in irrigated soils can be predicted with reasonable accuracy from constituents in irrigation water using Gapon's equation, soluble Na percentage, or the Na adsorption ratio as the basis for estimation. Exchangeable Na percentage can be estimated with an accuracy of ± 1.8 at the 0.90 probability level for 25 out of the 26 soils.Correlation between conductivity of soil saturation extracts and that of irrigation water was 0.98 when observations were restricted to soils that (a) increased in total salt content upon irrigation and (b) in which conductivity of the saturation extract exceeded that of irrigation water. Maximum irrigation water electrical conductivity used on such soils was 2.28 mmho per cm. For this value, soil saturation extract electrical conductivity could be predicted with an accuracy of ± 0.54 mmhos per cm. at the 0.90 probability level.Electrical conductivity of soil saturation extracts varied from 0.4 to 4.7 mmho per cm. at 25° C. Mean exchangeable Na percentage ranged from 0.1 to 6.2. Irrigation water ranged in conductivity from 0.3 to 4.9 mmho per cm. at 25° C.
The Effect of Atomic Weight of the Saturating Ion on the (001) X‐Ray Diffraction Peaks of Layer Silicates
Authors: Kittrick J. A. 
Published: July 2010

AbstractIt was found that Tl+ saturation strongly diminished the intensity of the diagnostic (001) peaks of glycerated montmorillonite and vermiculite. Further experiments showed that the (001) X‐ray diffraction peak of expanding layer silicates decreases with increase in the amount of X‐ray scattering material contributed by the ions saturating the exchange sites. Intensity calculations indicate the mechanism to be ordinary destructive interference of diffracted X‐rays and that Tl+ contracts vermiculite to the mica structure.
Hydraulic Gradients Associated with Infiltration in Field Studies
Authors: Cannell Glen H. , Stolzy L. H. 
Published: July 2010

AbstractA field method is described for measuring hydraulic head changes with time during infiltration of water into the soil. Using graphical methods, the hydraulic head and hydraulic gradient relationships for depth with time were established. From the sets of curves developed, soil depths were determined where soil physical properties influenced water flow during infiltration.
Miscible Displacement: II. Behavior of Tracers
Authors: Biggar J. W. , Nielsen D. R. 
Published: July 2010

AbstractIt is of interest to know the microscopic flow velocity distribution of water moving through soil. Dissolved constituents frequently have been used to trace water movement in porous materials. It is apparent from this and previous investigations, that the distribution of a tracer some distance from its source, depends upon the geometry of the porous material and the physical and chemical interaction of the tracer solution and media during flow. Therefore, investigators studying water movement using tracers are compelled to ascertain the importance of the interaction of tracer solution in the media. Tritium and chloride ion were used as tracers for water flowing under stationary conditions in laboratory soil columns. The distribution of the tracers measured in the effluent is explained on the basis of the relative effects of pore geometry, diffusion rates, adsorption and exchange.
Gamma Scintillation Spectrometry of Soil and Tree Leaves
Authors: Mortensen J. L. 
Published: July 2010

AbstractA two‐crystal spectrometer was developed for gamma scintillation spectrometry of low‐level environmental samples. Response to gamma‐rays and resolution, efficiency, and background characteristics of the spectrometer were determined.Spectra of gamma emitters in Canfield silt loam sampled in August, 1960, showed the presence of thorium + daughters, uranium + daughters, K40, Cs137 (190 mc. per mile2), Ru106‐Rh106 (885 mc. per mile2) and Ce144‐Pr144 (1275 mc. per mile2). Spectra of tree leaves obtained in the fall of 1959 and counted in June, 1960 showed the presence of Ba140‐La140, K40, Ru106‐Rh106, Zr95‐Nb95, Cs137, Ce144‐Pr144. Leaves sampled in the fall of 1960 contained K40, Cs137, Ru106‐Rh106 and Ce144‐Pr144.
The Aeration‐Recovery Method for Determining Ammonium Fixation by Soils Under Moist Conditions
Authors: Leggett G. E. , Moodie C. D. 
Published: July 2010

AbstractA method for determining NH4 fixation by soils under moist conditions is described. Alkaline aeration in the presence of K is used to remove the soluble and exchangeable NH4 from NH4‐treated soil. The liberated NH3 is collected in standard acid and determined by titrating with standard NaOH. The NH4 fixed by the soil is obtained from the difference between NH4 added and that recovered.Comparative data presented for several soils indicate that NH4 fixation values obtained by the proposed method agree with those obtained by determining the difference in N content of NH4‐treated and untreated samples after extracting with KCl solution to remove the soluble and exchangeable NH4.Data are presented which indicate that NH4 fixation by soils may be measured with a precision of ±0.1 me. per 100 g. by the proposed method.
The Absorption of Nutrient Elements by Tomatoes Associated with Levels of Bulk Density
Authors: Flocker W. J. , Nielsen D. R. 
Published: July 2010

AbstractData are presented to show some of the relationships between soil moisture tension, air space, and soil density and their effect on the total nutrient absorption by tomato plants. Every effort was made to establish clearly defined treatments and evaluate changes in soil moisture during the experiment. The experiment consisted of two parts. In one, integrated mean air space was maintained at 0.15 cm.3 per cm.3, while densities ranged from about 1.2 to 1.6 g. per cm.3, resulting in integrated mean soil moisture tensions from 0.01 to 5 bars; in the other, for the same densities, mean soil moisture tension was 0.7 bar, and consequently mean air space ranged from about 0.32 to 0.09 cm.3 per cm.3 In almost every case there was a significant negative correlation between total nutrient absorbed per plant and increasing soil moisture tension. Total nutrient absorbed by the plant was independent of density as long as soil moisture tension was 0.7 bar, even though density and air spaces were maintained over a wide range. Likewise, except for boron and phosphorus, a positive correlation was found between concentration of nutrient absorbed at time of harvest and soil moisture tension. No significant correlation existed when soil moisture was maintained at 0.7 bar.
Effect of pH on the Sodium‐Calcium Exchange Equilibria in Soils
Authors: Pratt P. F. , Whittig L. D. , Grover B. L. 
Published: July 2010

AbstractThe Na‐Ca exchange equilibria in 10 acid soils were measured at pH values of 5, 6, 7 and 8 and the results related to a theoretical ion exchange equation based on the Poisson‐Boltzmann differential equation of the electrical double‐layer. The theoretical equation satisfactorily predicted the relative change in ratio of adsorbed Na to adsorbed Ca as the pH of the equilibrium solutions decreased. The actual values of ratios of adsorbed Na to adsorbed Ca agreed with the theory when the surface charge densities for each soil were multiplied by an appropriate factor. This factor varied from 1.0 to 2.1 but was the same for all pH values for a given soil.
Soil Development in Relation to Loessial Deposition in Southeastern Minnesota
Authors: Foss J. E. , Rust R. H. 
Published: July 2010

AbstractThe soils of southeastern Minnesota and adjacent areas are found to be developed mainly on loessial parent material of Wisconsin age. The origin, distribution, and some properties of the loess were studied. Loess deposition in southeastern Minnesota was found to have a general relationship to distribution of the major river valleys of the area. Measurements of loess thickness, determination of particle size analysis, and of calcium carbonate distribution provided evidence for this conclusion.The characteristics of two loess‐derived profiles developed under forest cover were studied. The profiles were selected to represent a range in degree of horizon development. The differences in profile development appear to be largely the result of weathering time.
A Test for Natural Soil Groups Within the Willamette Catena Population
Authors: Pomerening J. A. , Knox E. G. 
Published: July 2010

AbstractA sample of 114 soil individuals, from Marion County, Oregon, representing the five soil series of the Willamette catena, was tested for the existence of natural soil groups. Natural soil groups are those separated by minima in frequency distributions of single or combined soil characteristics.Eighty‐five morphological, chemical, and physical properties were quantitatively measured on each individual. Frequency distributions were tabulated for each property and examined for the presence of minima. Frequency distributions for depth to evidence of impeded drainage, cation‐exchange capacity of the B2 horizon, and exchangeable magnesium of the B3 horizon showed minima.Discriminant function analysis was used to test the combined differentiating abilities of several selected characteristics. Minima were observed in frequency distributions for those combined functions which included a differentiating characteristic. The natural groups separated by these minima corresponded to the recognized soil series.
Effects of Rainfall Energy on the Permeability of Soils
Authors: Sor Kamil , Bertrand A. R. 
Published: July 2010

AbstractThe effects of simulated rainfall on the air and water permeabilities of sand and several disturbed soil samples were investigated. Various rainfall intensities were provided by a rainfall simulator. Soil was packed in a cylindrical infiltrometer, to which was connected eight manometers. Permeability of the soil to water was measured during and after the application of rainfall.It was found that a rainfall of 30 minutes duration at an intensity of 2.8 inches per hour caused maximum change in water permeability of the soils. Water permeability of quartz sand was not changed by rainfall. Water permeability of soils was changed; (a) only in top 1.5 cm. by 1.6 inches per hour rainfall, (b) greatly in top 1.5 cm. and somewhat less in second 1.5 cm. layer by 2.8 and 4.0 inches per hour rainfall. In saturated soil columns, water permeability was not governed entirely by the permeability of the least permeable layer. The thickness of the dispersed and compacted soil layer appeared to be about 1 mm. Below it a less compacted layer, about 3 cm. deep, resulted.
Mechanical Impedance and corn Seedling Root Growth
Authors: Phillips R. E. , Kirkham Don 
Published: July 2010

AbstractUsing needle penetration and bulk density as measures of mechanical impedance, the effects of mechanical impedance on corn seedling root growth were studied in the laboratory. The corn seedlings were grown in artificially compacted samples of a Colo clay where the moisture was at a tension of 10 cm. in some samples and 100 cm. in others. The rate of corn seedling root elongation decreased linearly as bulk ensity of Colo clay increased from 0.94 g. per cc. to 1.30 g. per cc., or as needle penetration into the Colo clay decreased. In ohter laboratory experiments, the depth of corn seedling root penetration into sand contained in glass tubes of differing diameters was found to be linearly related to the depth of penetrometer penetration.
The Temperature Effect on the Equilibrium Energy Status of Water Held by Porous Media
Authors: Wilkinson G. E. , Klute A. 
Published: July 2010

AbstractWater held in porous media is under the influence of a number of forces. The energy of the water in these force fields may be described with the aid of the potential theory of classical physics or with the aid of classical thermodynamics. Desorption curves were determined for two sand fractions and a silt fraction at 48° and 44°C. Temperature coefficients of the potential calculated on the basis that surface tension‐radius of curvature was the principle water‐holding mechanism were compared with the experimental observations. The results indicated that in the fine sand (53–74µ) and silt (13.5–18.0µ) other mechanisms besides surface tension‐radius of curvature may be involved in holding the water in the porous medium.
Organic Materials Which Stabilize Natural Soil Aggregates
Authors: Greenland D. J. , Lindstrom G. R. , Quirk J. P. 
Published: July 2010

AbstractThe effect of periodate followed by sodium borate treatment on the stabilities of prewet soil aggregates has been determined by a permeability technique and by wetsieving. The effect of periodate treatment depends on the history of the site, the depth, and the great soil group from which the sample is taken. The stabilities of aggregates from various Red Brown Earths were all reduced by periodate treatment. The reduction was small for samples from plots which had been under pasture for many years, but very large for samples which had been under pasture for 4 years or less, or which were continuously cropped. The stabilities of all subsurface samples of the Red Brown Earths were completely destroyed by periodate treatment. Aggregates taken from a Solonized Brown soil were much less sensitive to periodate treatment, and those taken from a Rendzina were with one exception unaffected. These soils contain free CaCO3. It is probable that the most important function of the periodate treatment is to cause breakdown of the polysaccharides and polyuronides in the soil, and the results show that in cropped soils and soils under young pastures aggregate stability is primarily due to these materials. In soils under older pastures, or soils which contain free CaCO3, other materials prevent aggregate breakdown.
Sterilization of Soil by Irradiation and Some Further Observations on Soil Enzyme Activity
Authors: McLaren A. D. , Luse R. A. , Skujins J. J. 
Published: July 2010

AbstractAs an introduction to the study of radiation‐sterilized soil as a medium for microbial and plant growth, survival curves for microorganisms have been obtained with 5 and 9 Mev. electrons, hard X‐ray and gamma radiation. For a given soil, bacterial survival curves with these radiations are almost superimposable, but they differ among soils. Bacterial numbers in soils approach zero at 2 Mrep. doses, but 4 Mrep. doses are necessary to insure complete sterility for larger soil volumes.Soil sterilized by radiation still manifests enzyme activity (phosphatase, urease) in the presence of suitable substrates. If this is a general situation, studies of the uptake of some organic nutrients from sterile soil by sterile root systems will not be free from the problem of hydrolysis in situ. Sterilized soil is not toxic toward tomato plants nor does it provide extra nutrient to the plants as a result of radiation. It does, therefore, provide the plant physiologist with a medium for the study of uptake of inorganic nutrients by sterile plants which possesses all the purely chemical and structural features of natural soil.
Some Studies of the Autotransformation of H‐Bentonite to Al‐Bentonite
Authors: Davis L. E. , Turner R. , Whittig L. D. 
Published: July 2010

AbstractDuplicate samples of suspensions of H‐bentonite prepared by the method of Aldrich and Buchanan (1) were heated at 35°, 50°, 65°, 80° and 95°C. At appropriate time intervals, samples were removed, cooled to 25°C., and titrated electrometrically with NaOH solution. The titration curves were markedly differentiated functions of time and temperature of heating.Specimens heated for various periods at 95°C. were analyzed for the amount of replaceable Al and examined by X‐ray diffraction analysis. Replaceable Al increased progressively with time of heating. X‐ray diffraction analysis revealed that basal spacings and intensity of diffraction maxima increased with time of heating. The authors conclude that these changes are related to increase in the ratio of replaceable Al to H.
Relative Value of Calcium Metaphosphate and Superphosphate as Sources of Phosphorus for Plants on Different Soils
Authors: Allmaras R. R. , Black C. A. 
Published: July 2010

AbstractAvailability‐coefficient ratios (ACR) of phosphorus in calcium metaphosphate (CMP) to phosphorus in concentrated superphosphate (CSP) applied to 11 soils were obtained from data on yields of phosphorus in plants in a greenhouse experiment. ACR values ranged from 0.61 to 1.25 and were lower for calcareous than for acid soils. The best index of ACR values was provided by the increase in orthophosphate in the soils as a result of addition of CMP and partial hydrolysis of the condensed phosphate it contains. The increase in orthophosphate was estimated by (a) adding different quantities of P as KH2PO4 to soil, (b) incubating the soil under the same conditions employed for CMP, (c) finding the increase in orthophosphate by isotopic dilution of P32O4 in the presence of (CH3)4N‐resin, (d) plotting the observed increases in orthophosphate against the quantities of P added as KH2PO4, and (e) finding by interpolation in the plot of (d) the quantity of P added as KH2PO4 to which the observed increase in orthophosphate with CMP was equivalent. The relative increases in orthophosphate present in water extracts of the soils as a result of application of CMP or CSP provided a good index of ACR values in most soils but not in all. The gross movement of P from CMP into surrounding soil provided a relatively poor index of the ACR values. The results indicate that in soils treated with CMP, the P absorbed by plants comes mainly from the orthophosphate and not directly from the condensed phosphates.
Soils of Indian Mounds in Northeastern Iowa as Benchmarks for Studies of Soil Genesis
Authors: Parsons R. B. , Scholtes W. H. , Riecken F. F. 
Published: July 2010

AbstractA study was made to evaluate the degree of horizon development in seven prehistoric Indian mounds of known age in northeastern Iowa. Comparisons were made between the data obtained for the Indian mound soil profiles and two virgin, loess‐derived Fayette profiles from the landscape near the mounds. The parent materials for the mound soils were the leached upper horizons of the soils under and immediately adjacent to the mounds.Morphologically, the mound profiles exhibited pronounced A1 horizons, weak color and structural A2 horizons, and incipient B horizons. Differences in profile development among the mounds were attributed to differences in mound age. The development of soil profiles in the mounds has been the most pronounced during the first 1,000 years. The mounds have reached their greatest present horizon expression in a period of no more than 2,500 years, and are similar in many respects to the Fayette soils which have developed over a period of no more than 14,000 years.