bluuebunny/crossref_metadata_2025_split huggingface dataset:
Titration of H‐Al Bentonite With Tetra‐Alkyl Ammonium Bases
Authors: Spain J. M. , White Joe L. 
Published: July 2010

AbstractIt was postulated that tetra‐alkyl ammonium hydroxides would be useful in the titration of acid clay systems because of their base strength and the stability of complexes formed between the tetra‐alkyl ammonium cations and clay minerals. Conductometric titrations of H‐Al bentonite were performed using tetramethyl‐ and tetraethanol‐ammonium hydroxides; the resulting titration curves were very similar to those obtained with strong inorganic bases.An improved titration procedure was devised in which a vacuum tube a.c. volt meter was used to determine the null point. Separate small aliquots of clay suspension were titrated with different increments of base equivalent to successive points on a titration curve. This technique permitted an examination of the magnitude and rate of resistance change after the addition of any given increment of base. For lithium hydroxide and tetramethyl ammonium hydroxide, 2 to 3 hours were required for the resistance of the suspensions to become essentially constant. It is concluded that conventional titrations, even with strong inorganic bases, may be subject to considerable error.An explanation of the time dependency of the conductometric titration of H‐Al bentonite systems was offered in terms of differences in diffusion rates of cations in the system. A postulated mechanism for the conversion of an H‐bentonite into an H‐Al bentonite was presented.
The Effect of Rates of Application of Ammonium Sulfate on Gaseous Losses of Nitrogen from Soils
Authors: Carter J. N. , Allison F. E. 
Published: July 2010

AbstractAdditions of (NH4)2SO4 to a sandy loam at concentrations corresponding to those that might be found in band applications resulted in losses of 0 to 30% of the added nitrogen in forms other than ammonia. In these studies of limed and unlimed soils, where the pH values were in the range of 4.7 to 6.9, the losses increased with increase in ammonium sulfate additions and were greater on limed than on unlimed soil.Losses of ammonia by volatilization from the soils during incubation periods of 6 to 10 weeks were negligible. Losses of ammonia during air‐drying of these soils following incubation and prior to analysis were also negligible in the absence of lime, but were as high as 15% on soils limed to pH 6.7 and receiving the largest amount of (NH4)2SO4. Gaseous losses of nitrogen from two silt loams were much smaller than from the sandy loam.
Photomicrographic Study of Soil Aggregates and Microorganisms As Influenced by Stubble Mulching and Plowing
Authors: Turelle J. W. , McCalla T. M. 
Published: July 2010

AbstractA photomicrographic study was made of the soil at the surface of stubble‐mulched and plowed soil plots on July 7, August 28, and October 22, 1959. These soils had been subjected to stubble mulching or plowing for a 20‐year period. The plots were in corn in 1959 following wheat in 1958. The surface of the stubble‐mulched soil had larger soil aggregates and voids than plowed soil. Contact slides placed in the plots showed more microorganisms on stubble‐mulched than on plowed soil.Water‐stable aggregates from each type of tillage were also embedded in plastic compounds. These aggregates were sliced in sections 30 and 0.2µ thick and photomicrographed with light and electron microscopes, respectively. A major problem was the impregnation of soil aggregates for sectioning. The cross‐sections of aggregates from stubble‐mulched plots seem to be less compact and more porous than from plowed plots in both the 30 and 0.2µ sections of soil aggregrates.
Modal Analysis of Soils
Authors: Anderson Duwayne M. , Binnie R. R. 
Published: July 2010

AbstractThe statistical elements of petrographic modal analysis are reviewed. The application of this procedure to soils and unconsolidated sediments is discussed and justified. Application of this method to obtain more complete quantitative estimates of mineralogical composition and pore space of soils should facilitate progress under the present system of soil classification and promote the use of objective criteria in new classification schemes.
Inefficiency of Fertilizer Use Resulting from Nonuniform Spatial Distribution: I. Theory
Authors: Jensen Don , Pesek John 
Published: July 2010

AbstractNonuniform physical distribution of a fertilizer nutrient was expressed as a function of space coordinates and substituted into an equation which characterizes yield response to that nutrient. The resulting differential equation was then integrated over the area fertilized to give a new yield potential function which is valid under any specified nonuniformity restriction. In particular, a periodic cosine function with amplitude “a” was selected to represent the spatial distribution function for a single fertilizer nutrient, while a quadratic equation of the form Y = b0 + b1X + b11X2was used to express the relationship between yield and the nutrient. The new yield potential equation
urn:x-wiley:03615995:saj2sssaj196203615995002600020022x:equation:saj2sssaj196203615995002600020022x-math-0001 was derived from these particular functional forms. Yield loss associated with the cosine distribution pattern then was obtained as the difference between the ideal and the restricted production equations.A corresponding derivation was made for the case of n variable factors of production under the assumption of a quadratic response equation and distinct cosine laws for physical distribution of each variable. Yield losses were expressed in the form
urn:x-wiley:03615995:saj2sssaj196203615995002600020022x:equation:saj2sssaj196203615995002600020022x-math-0003 where bij is the coefficient for interaction of the i'th and j'th factors, and ai and aj are respective amplitudes of the cosine distribution funcations of the i'th and j'th nutrients.
Nitrification as Affected by Temperature and Moisture Content of Mulched Soils
Authors: Parker D. T. , Larson W. E. 
Published: July 2010

AbstractIn the temperature range of 16° to 20°C., a 2°C. differential in soil temperature had a measurable effect on the rate of conversion of NH4‐N to NO3‐N. However, as soil temperature increased to the range of 25° to 30°C. or as the supply of NH4‐N became limiting, differences in NO3‐N production resulting from small differences in soil temperature were not observed. In field soil, very early in the season when soil temperature was in the range of 16° to 20°C., mulched soil was 1° to 2°C. cooler than bare soil. During this period greater accumulation of NO3‐N could occur in bare than in mulched soil as a result of the temperature difference.As measured in the laboratory, NO3‐N production was retarded at soil moisture tensions below 50 cm. of water. At still higher moisture levels, considerable mineral N was lost from the soil. Measurements in the field showed that the soil moisture content of mulched soil exceeded that of bare soil. For short periods of time the moisture level of mulched soil was high enough to cause retarded nitrification and loss of N.
Sorption of Anhydrous Ammonia by Dry Clay Systems
Authors: Brown James M. , Bartholomew W. V. 
Published: July 2010

AbstractNH3 sorption and/or retention over the pressure range of 0 to 100 ml. of mercury by dry bentonite, halloysite, and synthetic gibbsite was investigated using a manometric technique employing equilibrium measurements in a special sorption apparatus. Chemisorbed NH3 is believed to be that which has gained a proton and undergone exchange reactions with the exchangeable cations and that which has reacted with the weakly dissociated hydroxyl groups of the lattice edges. The differential influence of saturating cations is believed to be due, at least in part, to the differences in degrees of hydration of these ions. Possible mechanisms of sorption are proposed.There were no differences in amounts of NH3 sorbed and chemisorbed by Ca‐bentonite adjusted to pH 8, 9, and 10. This lack of influence is explained on the basis of the pH range involved and the mechanisms of sorption. The failure of synthetic gibbsite, Al(OH)3, to chemisorb NH3 is explained by the basic nature of the mineral.
Characteristics of Some Brown Grumusols of Arizona
Authors: Johnson W. M. , Cady J. G. , James M. S. 
Published: July 2010

AbstractExtensive areas of well‐drained brown Grumusols developed from weathered ultrabasic volcanic rocks exist in north‐central and eastern Arizona. They are on nearly level to rolling topography under grass; precipitation ranges from < 10 to > 20 inches annually. They have clay profiles of nearly uniform brown color; moderately low organic matter content; very high base status; dominance of montmorillonite in the clay fractions; and evidence of much internal soil movement, namely: numerous slickensides, very gradual decrease of organic matter with depth, and diffuse or gradual and wavy horizon boundaries. Mineralogical studies indicate that in these soils the course of weathering of the rock and the nature of the weathering products are determined early and remain constant; montmorillonite is the dominant clay mineral in all horizons including the weathered material adjacent to the fresh rock. Comparisons are given with associated dark gray, poorly‐drained Grumusols and with dark brown soils having textural B horizons that formed under timber‐grass vegetation.
The Interaction of the Simultaneous Diffusions of Heat and Water Vapor
Authors: Cary J. W. , Taylor S. A. 
Published: July 2010

AbstractThe theory of thermodynamics of irreversible processes and the Onsager reciprocal relation were tested for the case of thermally induced water vapor diffusion through air and through moist soil in the temperature range of 15° to 45°C. The general rate equations for heat and mass flow were transformed into simple relations giving the flux as a function of temperature.The simultaneous steady state rates of heat and vapor flow through air and moist soil were measured. A portion of these data was used to solve for the specific phenomenological coefficients, and the remainder was used to test the rate equations. It appeared that the rate equations so derived, were applicable over the range of soil conditions tested. Furthermore, the interaction coefficients between heat and vapor flow and between vapor and heat flow were found to be nearly identical, which was in agreement with Onsager's theory.
Seedling Emergence of Wheat, Grain Sorghum, and Guar as Affected by Rigidity and Thickness of Surface Crusts
Authors: Taylor Howard M. 
Published: July 2010

AbstractA nonporous wax surface crust technique was devised to study seedling emergence of wheat, grain sorghum, and guar. Emergence through crusts with wax penetration numbers ranging from 15 to 80 was evaluated using crust thicknesses of ¼, ½, and 1 inch.Seedling emergence of wheat, grain sorghum, and guar was affected by hardness and by thickness of crusts. A curvilinear relationship existed between seedling emergence and crust hardness. No emergence occurred in any of the 3 plant species when the wax penetration number was 27.0 or less. There was no difference between species in this critical wax penetration number. As crust thickness increased, higher wax penetration, i.e., softer waxes, were required before any seedling emergence occurred.
Inhibition of Germination and Seedling Development by Crop Residues
Authors: Guenzi W. D. , McCalla T. M. 
Published: July 2010

AbstractWheat and oat straw, soybean and sweetclover hay, corn and sorghum stalks, bromegrass and sweetclover stems were extracted with hot and cold water, using 1 part of residue to 15 parts of water. One‐half of the water extract of each residue was autoclaved for 1 hour at 20 pounds steam pressure. In addition, wheat straw was extracted with ethanol and the extract was separated into strong and weak acids, neutral, basic, and water‐soluble compounds. The ethanol‐soluble compounds were tested for their effect on wheat, whereas the hot and cold water extracts of residues were tested for their effect on germination and growth of wheat, sorghum, and corn seeds.All the residues contained water‐soluble substances that inhibited the germination and growth of sorghum, corn, and wheat. The cold water extracted more toxic materials than did the hot water. Autoclaving increased the toxic effect of the water extract of residues on root growth. The toxic effect on germination and shoot growth was decreased for most residues by autoclaving of aqueous extract. Ethanol‐soluble substances of wheat straw inhibited the germination and growth of wheat seeds. The ethanol extract of wheat straw, separated into strong acid, water‐soluble, neutral, weak acid, and basic compounds, showed decreasing toxicity in the order listed.
Microbiological Processes Associated with the Use of Chitin for Biological Control
Authors: Mitchell R. , Alexander M. 
Published: July 2010

AbstractIn an investigation of the mechanism of action of chitin in the biological control of Fusarium solani f. phaseoli in soil, statistically significant control of a root rot caused by the fungus was noted when the aminopolysaccharide was added to soil up to 2 weeks prior to planting. No significant suppression by the microflora responding to the amendment was observed in longer periods of preincubation. Saprophytic soil fungi were also inhibited during the first 2 weeks after chitin incorporation. Actinomycetes, chitinase‐producing microorganisms, and chitinase activity were markedly stimulated during that period of time, but the population of bacteria was not altered appreciably. It is suggested that mycolytic activity and toxin production may be implicated in the selective influence of chitin in suppressing certain soil fungi. Acetate effectively controlled disease, but it appears that the mechanisms of action of chitin and acetate are distinct.
Decomposition in the Field of Buried and Surface‐Applied Cornstalk Residue
Authors: Parker D. T. 
Published: July 2010

AbstractThe decomposition of cornstalk residue placed on the surface of soil or buried in soil in the field was followed during a corn crop‐growing season by removing from the soil at various times subsamples of decomposing residue contained in glass‐cloth bags. Decomposition during the season (20 weeks) amounted to 50% of the surface residue and 65% of the buried residue. Half of this decomposition occurred in 8 weeks and in 5 weeks for surface and for buried residue, respectively.There was little change in the total N content of surface residue throughout the season. Nitrogen was not immobilized. However, the C/N ratio declined from 57 to approximately 30.A maximum of 12 pounds of N per 3 tons of residue per acre was immobilized by buried residue. This occurred after 3 weeks incubation. Thereafter, total N content of the residue declined. A net loss of N occurred after 5 weeks with no N fertilization and after 15 weeks' with N fertilization. The C/N ratio declined from 57 to 22. The decline in C/N ratio, both with surface and with buried residue, was caused by loss of carbon from the residue rather than an increase in total N.Early season growth of corn plants was retarded by surface residue, but the retardation was not a consequence of N immobilization. A slight retardation of growth with buried residue might, in part, have been caused by immobilization of N.
The Effect of Wetting Agents on Infiltration
Authors: Pelishek R. E. , Osborn J. , Letey J. 
Published: July 2010

AbstractLaboratory studies conducted on the effect of wetting agents on infiltration rates indicated that (1) a wetting agent can increase infiltration rates into hydrophobic soils but have either no effect or adverse effects on soils which are not particularly hydrophobic; (2) the wetting agents used in the study produced a beneficial residual effect; and (3) the wetting agent is not completely leached from thatch.
Effect of Partial Surface Covers on Evaporation from Soil
Authors: Willis W. O. 
Published: July 2010

AbstractEvaporation rates from small columns subjected to convected energy under laboratory conditions were found to be dependent on both percent of surface covered by plastic film and on size of continuous area exposed. Partial covers appear to be most effective when the soil is wettest. When the energy available for evaporation is supplied by convection, the most efficient covering pattern for evaporation control will probably be one which provides as large a continuous cover as practical, as well as one with the least exposure of soil surface.
The Use of Ferrosul, a Steel Industry Byproduct, as a Soil Amendment
Authors: Stroehlein J. L. , Berger K. C. 
Published: July 2010

AbstractThe disposal of spent pickle liquor (largely spent sulfuric acid and sulfate of iron) has long been a problem of the steel industry. Ferrosul, a neutralized and precipitated pickling material, was applied to field plots at rates of 200,000 and 400,000 pounds per acre. Corn was grown with and without starter phosphorus fertilizer treatments to determine if phosphorus was fixed by the iron in Ferrosul. The ferrosul and phosphorus treatments had little effect on corn grain yield when compared to check plots.Corn and alfalfa were grown in the greenhouse on Plainfield sand and Miami silt loam soils treated with 1, 10, 20, and 40% Ferrosul on the weight basis, as well as an untreated check. It was found that corn yields were best on the 1% treatment with the Plainfield sand as a result of a sulfur deficiency of the check. Corn yields were decreased at the 40% level with both soils. Alfalfa yields were generally best with the Ferrosul treatments. The highest total yield of eight harvests was with the 20 and 40% treatments with the Miami and Plainfield soils, respectively. Phosphorus fixation was not found to be a problem when additions of phosphorus fertilizer were made.It is concluded that large amounts of Ferrosul can be applied to agricultural land without detrimental effects on crops and soils.
Chemical and Mineralogical Characterization and Comparison of Hagerstown and Maury Soil Series
Authors: Hutcheson T. B. 
Published: July 2010

AbstractMaury and Hagerstown soil series have largely been differentiated in central Kentucky on the basis of phosphate level as determined by chemical quick test in the field. Slight color differences have been noted, but considerable overlap of this criterion exists. Consequently, field differentiation of these two series without chemical testing is most difficult. Chemical and mineralogical data obtained for three Maury and two Hagerstown profiles point up the similarity between the two series as well as illustrate about as much range in many properties within the individual series as between them. These data suggest that as the soils occur in central Kentucky, differentiation at the series level is not justified.
The Loss of Strontium90 from Small Cultivated Watersheds
Authors: Frere Maurice H. , Roberts Howard 
Published: July 2010

AbstractSoil samples were taken from the plow layer of eight small watersheds and analyzed for strontium90. Two watersheds in permanent pasture, with no recorded loss soil, contained about 90 mc. per square mile, which is slightly higher than an estimated total deposit at the time of sampling.The plow layer of six watersheds under cultivation was sampled by compositing soil cores taken on contours of each watershed. The Sr90 concentration of these samples was from one‐third to two‐thirds of that in the permanent pastures.The loss of Sr90 appeared to be influenced by length of slope and cropping history. No areas of Sr90 accumulation were found within these watersheds.
Role of Chelating Agents on the Availability of Nutrients to Plants
Authors: Wallace Arthur 
Published: July 2010

AbstractThe presence of natural chelating agents is one of several possible explanations of how plants are able to obtain Fe which ordinarily in soil is very insoluble. The role of such chelating agents in plant nutrition is mostly an unexplored field. Synthetic chelating agents are proving useful in supplying Fe and to a lesser extent Zn and Mn to plants under conditions in which plants are subject to deficiencies of those metals. The chelating agents keep the metals soluble in the soil and are taken up by the plants with the metals. The two components may be separated in the roots but both can be transported to leaves. Chelating agents without metals often compete with roots and soil for metals and are generally not a good method of correcting micronutrient deficiencies. There are other interactions of soils, chelating agents, and micronutrients. Plant species differ greatly in their responses to chelated metals and some fail to respond.
Root‐Soil Boundary Zones as Seen in the Electron Microscope
Authors: Jenny Hans , Grossenbacher Karl 
Published: July 2010

AbstractPlants were grown in bentonite clay and in permutite sand. After a suitable period, all void spaces were filled with liquid resin monomer which hardened to a stone‐like mass. Thin sections, a few hundred Angstrom units thick, were cut and observed in the electron microscope. The root is surounded by mucigel which fills the space between cell wall and mineral soil particles. Often it contains colonies of microbes. Contact between mucigel and clay surface is intimate. Colloid chemical interpretations are presented.
Ion‐Exchange Reactions of Cesium
Authors: Coleman N. T. , Craig Doris , Lewis R. J. 
Published: July 2010

AbstractColumn leaching experiments with 0.001N CsCl with 1N KCl or CaCl2 showed Cs sorption by a number of clays to be much larger from Ca than from K solutions. The sorption affinity of Cs relative to the complementary ion corresponded with that found by others for the Cs‐K ion pair, but in Cs‐Ca systems the Cs was sorbed to a larger extent than would have been expected from the results of experiments where Cs‐Ca ratios in the equilibrium solution were not so small.While all except a very small proportion of the sorbed Cs was displaced on leaching with 1N KCl, some 36 times as much remained after leaching with equal volumes of 1N CaCl2.Vermiculite sorbed very large amounts of Cs (about 1/3 of exchange capacity) from 0.001N CsCl‐1N CaCl2. The sorbed Cs was largely “fixed” against exchange with 1N CaCl2. This suggests that Cs contained in interlayer spaces of vermiculite results in interplanar distances which will admit K but not Ca.
Chemical Distribution of Added Nitrogen in Soils
Authors: Cheng H. H. , Kurtz L. T. 
Published: July 2010

AbstractThe distribution of added nitrogen (N) among the various components of soil N was determined, using isotopic tracing techniques. Three lysimeter soils, previously fertilized with N15‐enriched N, were studied. Methods of fractionating soil N were modified to permit estimation of the isotopic ratio as well as the N content of the different fractions. Soil N was fractionated into: exchangeable NH4+ plus NO3‐, fixed NH4+, N in acid hydrolyzate, and acid‐insoluble humin N. The N in acid hydrolyzate was further separated into the alkali‐labile N and the alkali‐stable N. The alkali‐labile N consisted of hydrolyzed NH4+ and amino sugar N. The alkali‐stable N was divided into soluble N, which included the amino acid N, and acid‐soluble but alkali‐insoluble humin N. Validity of the classification was discussed. Usefulness of N15 data was also evaluated. Estimation of the distribution of added N showed that over 90% of added N in soils was found in the hydrolytic products of soil organic matter, mainly as amino acid N, amino sugar N, and other soluble N.
Urea Hydrolysis and Subsequent Loss of Ammonia
Authors: Chin Wei‐tsung , Kroontje Wybe 
Published: July 2010

AbstractThe biochemical hydrolysis of urea is rapid and can be related to soil microbial activities. The reaction rate of the chemical hydrolysis of urea is very slow and insignificant in comparison with the biochemical hydrolysis. Ureanitrogen loss through ammonia volatilization proceeds rapidly and may immediately follow urea hydrolysis. Urea hydrolysis and ammonia volatilization from ammonium carbonate are first order reactions.