bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improvements in Construction and Use of Resistance Networks for Studying Drainage Problems
Authors: Vimoke B. S. , Tyra T. D. , Thiel T. J. , Taylor G. S. 
Published: July 2010

AbstractA resistance network analog is described which incorporates some improved features in flexibility, accuracy, and ease of operation. The network consists of 575 variable resistance units and is mounted on a 6‐ by 8‐foot board. The resistive units are of the plug‐in type, and the mesh size is smaller on one‐fourth of the board. The use of a control console, automatic digital voltmeter and numerous switches permits rapid measurement of voltages and currents.Improved equations are presented for calculating network resistances adjacent to the drain. These equations utilize a logarithmic expression rather than a linear one as reported by previous investigators. Comparisons are made of drain flow rates in homogeneous medium as evaluated by the network and by analytic solutions of Kirkham. Compared to the analytical solutions, the network data generally deviates < 2% if the logarithmic expression is used to calculate drain resistors; while deviations as high as 30% or more may occur if a linear relationship is utilized.
Moisture, Pressure, and Formation of Water‐Stable Soil Aggregates
Authors: Rogowski A. S. , Kirkham Don 
Published: July 2010

AbstractMoisture and pressure treatments were applied to soil samples consisting of particles of 0 to 0.5 mm. diameter obtained by grinding 2 to 8 mm. aggregates of a Webster silty clay loam collected at the field moisture capacity and then air dried. The application of the moisture and pressure treatments formed the soil material into cylindrical briquettes and these, while moist, were broken into aggregates; these aggregates were then air‐dried and tested for water stability and finally the water‐stabilities resulting from the moisture‐pressure treatments were compared with the water‐stability of 2 to 8 mm. diameter aggregates of untreated soil material. It was found that, although pressure and moisture applied to ground soil material did increase water stability, the water‐stability which resulted from the pressure (maximum 1000 psi.) and moisture (maximum 30.5% referred to oven‐dry weight) was much less than was the water‐stability found in soil material not ground and not subjected to the pressure and moisture treatments. An important conclusion is that, since pressures as high as 1000 psi., which are in excess of pressures exerted by farm machinery, plant roots and soil fauna, failed to produce water‐stability comparable to that of untreated soil material, other forces are more responsible for water‐stable aggregate formation. These other forces may be due to chemical, biological or other natural factors. Concurrently with the work on 0 to 0.5‐mm. soil, identical moisture and pressure treatments were also applied to 2‐ to 8‐mm. diameter aggregates of this same Webster silty clay loam soil material. It was found that the moisture and pressure treatments resulted in decreased water‐stability of these treated 2‐ to 8‐mm. aggregates in comparison with the untreated 2‐ to 8‐mm. aggregates.
Determination of Al(III) in Plant Materials and Soil Extracts
Authors: Page A. L. , Bingham F. T. 
Published: July 2010

AbstractAccurate colorimetric determinations of Al(III) in plant materials and soil extracts containing up to 60 µg. Al(III) are made by employing the pH 4.2 aluminon buffer in conjunction with an ion‐exchange technique to remove interfering ions. Data are presented to show that it is not necessary to heat or to use a protective colloid when the Al(III) determination by the aluminon method is carried out at pH 4.2.The method was tested by comparing values obtained from plant materials and soil extracts using the proposed method with values obtained using the procedure of Yuan and Fiskell, and/or adding Al(III) to the extracts and determining the percent of recovery. Agreement between the two methods was satisfactory. The percent of recovery was essentially 100%. The effects of pH, temperature, boiling, and concentration of aluminon on the color intensity of the Al(III)‐aluminon complex are also reported.
The Relationship of Nitrogen in Corn Leaves to Yield
Authors: Baird Bruce L. , Fitts J. W. , Mason D. D. 
Published: July 2010

AbstractThe propriety of specifying rates of N fertilization by the use of the N content of the leaves of corn was evaluated.Steep slopes of both curves relating yield and N content of corn leaves to rates of N fertilization were associated with high correlation coefficients for the former two variables. These correlation coefficients consistently decreased, often becoming negative, as the rates of N fertilization were increased.An evaluation also was made of the percent N of corn leaves corresponding to the economic optimum yields and maximum yields of grain for the fertility experiments at 38 locations.Even though there may be good correlation between yield and N in the leaves, N content of leaves was a poor indicator of the rate of N fertilization. This was true for both economic optimum and maximum yields. The use of the percent N in the leaf should therefore be limited to the comparison of the effect of known factor variation under research conditions and not for the prediction of rates of fertilizer application.
Thermally Driven Liquid and Vapor Phase Transfer of Water and Energy in Soil
Authors: Cary J. W. , Taylor S. A. 
Published: July 2010

AbstractThe basic rate equation developed from Onsager's theory and thermodynamics of irreversible processes was modified for liquid phase moisture diffusion. This was done by accounting for the thermal dependence of the phenomenological coefficients with Eyring's theory of rate processes.The total simultaneous heat and water transfers through unsaturated soil samples were measured as a function of temperature gradient. By making use of the thermal dependence of vapor flow as reflected in the heat flux data, it was possible to separate the total water transfer into components of vapor phase flow and liquid phase flow. The rate equations were then tested and found to give reliable predictions of water and energy transfer through soil over the range of conditions applied. The interaction coefficients between heat and moisture transfer were also evaluated and found to be approximately the same, which was in agreement with the Onsager theory.
Laboratory and Greenhouse Investigations of Nitrogen Immobilization
Authors: Broadbent F. E. , Tyler K. B. 
Published: July 2010

AbstractImmobilization of tracer nitrogen added as ammonium sulfate or as nitrate was followed by analysis of inorganic nitrogen in Moreno sandy loam and Sacramento clay during the course of incubation experiments. In Sacramento clay receiving ammonium sulfate plus straw the nitrifying bacteria were able to compete effectively with the immobilizing flora for nitrogen, whereas in the Moreno soil this was not the case. In both soils immobilization attained a maximum in 6 to 10 days. There was some increase in inorganic nitrogen thereafter, but none of this resulted from remineralization of the tracer nitrogen added initially. In greenhouse experiments competition for added tracer nitrogen between a growing crop and the immobilizing flora emphasized preferential utilization of ammonium nitrogen by soil microorganisms and of nitrate nitrogen by the crop. In Moreno sandy loam, overall recovery of the added tracer was higher under treatments favoring immobilization than in pots receiving only fertilizer.
Radial‐Flow Cell for Soil‐Water Measurements
Authors: Richards L. A. , Richards P. L. 
Published: July 2010

AbstractA cylindrical ceramic cup, centrally placed in a cylindrical core sample of soil has several advantages over the conventional arrangement of a plane suction control surface at one end of a soil column. Flow disturbance arising from change of contact with the cup membrane when the sample shrinks is minimized and gaseous diffusion through the membrane is less troublesome for the evlindrical case. Ceramic cups usable to 15 bar are available. A drop counter is used for recording outflow and approach to equilibrium. The solution of the radial‐flow equation is given for the appropriate boundary conditions. The radial‐flow cell is useful for measuring retentivity, specific capacity, diffusivity, and conductivity of water in a core sample of soil having quasi‐undisturbed structure.
Soil Aeration and Plant Root Relations: IV. Testing the Cylindrical Shell Model in the Transient Case
Authors: Covey Winton , Lemon E. R. 
Published: July 2010

AbstractThis is a further study of the model of oxygen diffusion through a liquid cylindrical shell to plant roots, and the use of an oxygen cathode made of platinum wire to evaluate the resistance to diffusion. The transient current to the oxygen cathode is here analyzed mathematically, and the results compared to new measurements. Differences are believed due to an inadequate representation of the geometry of the soil‐air interface.
Numerical Solution of the Moisture Flow Equation for Infiltration into Layered Soils
Authors: Hanks R. J. , Bowers S. A. 
Published: July 2010

AbstractA numerical solution of the moisture flow equation was devised and programmed for an IBM 650 computer. Solutions obtained for infiltration into a loam over a silt loam and vice versa showed that infiltration was governed by flow through the less permeable soil, provided the wetting front had extended well into the second layer. Solutions were also obtained for vertical upward and vertical downward infiltrations and for horizontal infiltration into two soils. The numerical solution was found to give excellent results when compared with the methods of E. J. Scott et al. and J. R. Philip for horizontal infiltration into homogeneous soils at a uniform initial water content.
Soil Colloids as a Factor in the Uptake of Cobalt, Cesium, and Strontium by Plants
Authors: Graham E. R. , Killion D. D. 
Published: July 2010

AbstractA study of the uptake of Co, Cs, and Sr by rye, garden peas, and soybeans showed that the amount of these elements harvested, as well as the concentration in the plants, varied with the nature of the soil colloid on which they were grown.Illite, kaolinite, montmorillonite, peat (fibrous), peat (sedimentary), and Putnam clay were Ca‐saturated, mixed with nutrients and sand; and treated with known amounts of radioactive Co60, Cs137, and Sr85. Cultures of rye, peas, and soybeans were started in sand‐nutrient solution mixtures, then transferred to the radioactive colloid‐sand‐nutrient mixture. After a period of growth, the plants were harvested, weighed and assayed for their content of radioactivity. A study of the adsorption of the nuclides by the colloids was made by the determination of the distribution coefficient of each radioactive nuclide as a trace amount in Ca‐saturated exchange systems in 0.01M CaCl2 solution.The order of uptake of Co by the rye plants was highest on illite followed in order by kaolinite, Putnam clay, peat (sedimentary), montmorillonite, and peat (fibrous). The uptake of Cs by the rye plants was highest in the plants grown on (fibrous) peat (10.59% harvested), and lowest for the plants grown on Putnam clay (0.36% harvested). The uptake of Sr by the rye plants was highest for the plants grown on montmorillonite (2.08% harvested). The uptake of the nuclides by peas and soybeans followed closely that of rye.Data obtained from the distribution coefficient studies of the elements for the exchangers after equilibration in 0.01M CaCl2 solution reveals more Co adsorbed by the peats than by the clays; a high adsorption of Cs by illite and Putnam clays; and small differences with Sr with exchangers other than kaolin. The adsorption of the three elements was lower for kaolin than for the other cation‐exchangers. The percentage of Co and Cs harvested by the plants was correlated with the reciprocal of the distribution coefficient.
Factors Responsible for Poor Response of Corn and Grain Sorghum to Phosphorus Fertilization: I. Soil Phosphorus Level and Climatic Factors
Authors: Olson R. A. , Dreier A. F. , Hoover C. A. , Rhoades H. F. 
Published: July 2010

AbstractField experiments designed to measure the response of corn and grain sorghum to starter fertilizer containing P in Nebraska have shown both negative and positive responses to the starter. Positive responses have been associated with low soil P levels and negative responses with high soil P. These experiments also have shown that corn and sorghum are quite efficient in utilization of soil P, making optimum yields without fertilization possible with these crops on soils of substantially lower soil P supply than is possible with small grains.Excessive vegetative growth and water use with accentuated drouth damage accounted for yield decreases due to starter P in some experiments in dry years. In other cases, it appeared that a hastened physiological development due to applied P may have left the plant in the most critical stage of the reproductive cycle when dessicating weather conditions occurred, with resulting damage that was not apparent in later or earlier corn. In still other cases, there was evidence in plant appearance of a disturbed utilization of trace element(s) where starter P was applied, which is the subject of later papers in this series.
Cationic Effects on Sulfate Adsorption by Soils
Authors: Chao Tsun Tien , Harward M. E. , Fang S. C. 
Published: July 2010

AbstractThe magnitude of sulfate adsorption from different salt solutions, ranging 5 to 100 ppm. S, by soils was in the order CaSO4 > K2SO4 > (NH4)2SO4 > Na2SO4. The magnitude of sulfate adsorption by soils saturated with different cations followed the order of chemical valency of the saturating cations (Al3+ > Ca2+ > K+). The influence of different cations on sulfate adsorption was shown to be associated with two factors: nature of cations and pH. Resolution of the two factors indicated that pH had greater influence than the type of cations. As neutrality was approached, sulfate adsorption decreased considerably regardless of the type of saturating cation. However, there was still a cation effect in addition to the pH effect over the pH range studied. The influence of different cations was attributed to possible effects of electrokinetic potentials and anion repulsion. The effect of pH on sulfate adsorption was greater in soils containing higher amounts of sesquioxides, exchangeable aluminum and/or amorphous materials.
Urea Hydrolysis and Transformation in Some Illinois Soils
Authors: Simpson D. M. H. , Melsted S. W. 
Published: July 2010

AbstractSamples of several representative Illinois soils, ranging in pH from 4.9 to 7.2, were incubated under different conditions of temperature (1° and 25°C.), soil moisture content (24 and 60%), and urea concentration (200 and 400 ppm. N). The samples were analyzed for residual urea and NH4+ formed after time intervals ranging from 1 day to 4 weeks. Urea hydrolysis occurred at a nearly constant rate for an individual soil under given conditions. Hydrolysis rates varied widely among the different soils and environmental conditions studied, ranging from a minimum of about 6 ppm. N per day to a maximum of about 225 ppm. N per day. Urea hydrolysis rates were from 2 to 6 times greater at 25°C. than at 1°C., depending upon the particular soil involved. An increase in pH resulted in an increase in the hydrolysis rate. Different soil moisture contents and urea concentrations caused little change in the urea hydrolysis rates for individual soils. Nitrification of 400 ppm. urea‐N was followed over a period of 8 weeks for several soils. No measurable nitrification occurred in any of the soils at 1°C. The amount of nitrates formed at 25°C. varied from a minimum of 102 ppm. N in a Herrick silt loam, pH 4.9, to a maximum of over 400 ppm. in a Muscatine silt loam, pH 6.3.
Cicadas and Their Effect upon Soil Genesis in Certain Soils in Southern Idaho, Northern Utah, and Northeastern Nevada
Authors: Hugie V. K. , Passey H. B. 
Published: July 2010

AbstractThe occurrence, activity and effect of Western species of cicadas on soil formation and their relationship to soil characteristics were studied on 70 semiarid rangeland soils. The distinctive soil structure of some Western soils is attributed to the burrowing of cicada nymphs and has been produced over a long period of time. Filled cicada nymph burrows are called “cicada krotovinas.” Little mixing of soil horizons results from the activities of these insects.A new type of blocky soil structure, “cylindrical,” is proposed to describe cicada‐induced soil structure.Well‐drained, moderately permeable, moderately deep and deep silt loam, Brown and Sierozem soils, formed in loess parent materials, are well suited to cicada nymph activity. Few cicada nymphs or krotovinas are observed in soils with coarse textures, fine textural B horizons, and high bulk density.
Porosity and Soil‐Water Diffusivity Relations
Authors: Jackson Ray D. 
Published: July 2010

AbstractWater at −2mb pressure was absorbed by horizontal columns of three soil materials of differing texture each at three porosities, each porosity in duplicate. The soil materials were Adelanto loam, Pachappa loam, and Pine silty clay. From the water content distributions, soil‐water diffusivities were calculated, assuming applicability of diffusion theory. For a total porosity change of about 0.05, Pachappa loam exhibited little change in soil‐water diffusivity but Adelanto loam and Pine silty clay exhibited twofold to threefold changes in diffusivity at the same relative water content. Cumulative infiltration and distance of penetration of water into horizontal soil columns decreased 50% and 40%, respectively, for Adelanto and Pine and 15% and 12%, respectively, for Pachappa when the total porosity was decreased 0.05.Water content distributions were calculated using exponential diffusivity‐water content functions obtained by a least squares fit to the diffusivity data measured over a limited water content region. Predictions of water contents based on these functions were considerably in error.
Mathematical Study of the First Stage of Drying of a Moist Soil
Authors: Covey Winton 
Published: July 2010

AbstractIn the classical “first stage of drying” of a moist soil, constant external conditions produce a constant evaporation rate. The exponential dependence of moisture diffusivity on water content, suggested by W. R. Gardner, has been used for working out the changing soil moisture profiles in homogeneous soil columns, initially uniformly moistened, with gravity neglected. The characteristic parameter for the process is (βq0L/DI), where q0 is the evaporation rate [cm.3/(cm.2sec.)], β is a constant in the diffusivity equation D = γ · exp (β θ), L is the length of the column, and DI(cm.2/sec.) is diffusivity at initial moisture content θ1(cm.3/cm.3). If (β q0L/DI) is > 5, then the column behaves as an infinitely long column throughout the first stage of drying, and a newly‐computed universal relationship holds: β(θI − θ) = F [(βq0 x/DI), (β2 q02 t/DI)], where x is distance from evaporation surface and t is time. If (βq0L/DI) is < 5, then finiteness of length becomes important within the first stage of drying. The variable β(θI − θ) has been computed as a function of (x/L), (βq0t/L), and (βq0L/DI) for selected values of the latter. These new mathematical functions facilitate theoretical studies and the determination of desorption parameters from observations.
Comparison of Electrode and Flame Photometer Methods for Sodium Analysis of Soil Water
Authors: Fehrenbacher J. B. , Wilding L. P. , Beavers A. H. 
Published: July 2010

AbstractA total of 126 soil water samples from solonetzic soils in southern Illinois were analyzed for sodium by the electrode method using a Beckman (No. 78187V) Na+ sensitive electrode, and by the flame photometer method. The results obtained from these two methods agree closely as indicated by the highly significant correlation coefficient, r = 0.9989.
Sorption of Gaseous Ammonia by Clay Minerals as Influenced by Sorbed Aqueous Vapor and Exchangeable Cations
Authors: Brown James M. , Bartholomew W. V. 
Published: July 2010

AbstractAmmonia sorption by homoionic clay systems containing small amounts of adsorbed aqueous vapor was investigated by manometric techniques employing equilibrium measurements in a special sorption apparatus.Sorption isotherms from this investigation indicated that there is considerable interaction between ammonia sorption and moisture levels of the clays. At ammonia pressures below 60 to 100 mm. Hg, “dry” bentonite and halloysite sorbed more ammonia than comparable moist clays. At higher ammonia pressures, moist clays sorbed more ammonia than “dry” clays with the greatest amount of sorption occurring at the higher moisture levels.There was evidence of competition between aqueous vapor and ammonia for sorption sites on the clays. The kind of cation on the exchange complex also exerted an influence on ammonia sorption by moist clay, the mechanism of influence probably arising in part through alteration of the quantity and nature of the water of hydration.The same order of influence of exchangeable cations on ammonia sorption occurred with the moist clays as was previously reported for dry clays, i.e., Al‐clay > Ca‐clay > K‐clay.
Effect of Soil Temperature on Corn Plant Development and Yield: I. Studies With a Corn Hybrid
Authors: Mederski H. J. , Jones J. B. 
Published: July 2010

AbstractThe effect of 10° to 15° F. increase in field soil temperature on growth, yield, and ion accumulation by corn was investigated. In Ohio, normal field soil temperatures are below optimum for maximum corn plant development. Increasing soil temperature with heating cables installed beneath the row accelerated the rate of plant development, and produced significant increases in dry matter production and corn yield. Soil heating significantly increased N, P, K concentrations in plants sampled 30 days after planting. Soil heating did not significantly affect the composition of plants sampled at 60 days or at maturity.
Sulfur Supply of Soils and Crop Yields in the Southeastern United States
Authors: Bardsley C. E. , Kilmer V. J. 
Published: July 2010

AbstractThe sulfur level of soils from the no‐sulfur plots of 21 field experiments was estimated by three chemical methods using soil from the 0 to 12‐inch depth. The three methods were significantly correlated with percentage yield
urn:x-wiley:03615995:saj2sssaj196303615995002700020031x:equation:saj2sssaj196303615995002700020031x-math-0001 (R = 0.60) while the simple correlations with percentage yield were r = 0.55 for acetate‐soluble sulfate, r = 0.59 for bicarbonate‐extractable sulfur, and r = 0.44 for reserve + SO4‐sulfur.
The Canadian System of Soil Classification and the Seventh Approximation
Authors: Leahey A. 
Published: July 2010

AbstractSoil classification in Canada has developed on the concepts of great soil groups and soil series. The present system, officially adopted in 1960 by the soil survey organizations in this country, introduced the two categories of family and subgroup between the series and great groups and the category of order for combinations of great groups. Though based on soil profile features it has a strong genetic bias, expressed through selection of the differentiating criteria. The Canadian system and the Seventh Approximation are analogous at the series and family categories but differ markedly in the subgroup, great group, and order categories. Differences at these higher classification levels are due to differences in the selection of differentiating criteria, to the more restricted scope of the Canadian system, and to its lack of a suborder. The distinctly different nomenclature accents these differences.