bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field and Laboratory Studies of Nitrite Accumulation in Soils
Authors: Chapman H. D. , Liebig George F. 
Published: July 2010

AbstractA field and laboratory study of nitrite accumulation under arable soil conditions was carried out using a considerable number of nitrogen fertilizers applied at various seasons of the year. The results show that nitrite will accumulate under neutral or alkaline soil conditions provided the rate of fertilization is heavy enough to produce a considerable concentration of the ammonium ion. Under field conditions, especially where the soils are not warm enough for rapid biological activity, the nitrite produced may persist for several months. For example, nitrite accumulating from urea applied in January (43 ppm N as NO2) persisted into May (31 ppm N). Amounts of nitrite up to 90 ppm N were produced under favorable conditions. More nitrite was produced from urea than any other nitrogen fertilizer. This is considered due to the high ammonia and pH conditions resulting from application of this material. In none of the field studies was there any evidence of nitrite accumulation from denitrification though occasionally heavy fertilization with nitrate fertilizer supplemented with straw was immediately followed by heavy rains or irrigation. From these studies, it appears that wherever two conditions occur, namely, fairly high ammonium concentrations and neutral or alkaline soil conditions, more or less nitrite accumulation may be expected.
A Key for Evaluating Soil Permeability by Means of Certain Field Clues
Authors: O'Neal Alfred M. 
Published: July 2010

AbstractField clues to soil permeability were investigated at 182 locations from 1947 through 1951. Estimates of permeability were made in the field without prior knowledge of measured percolation rates. Then the estimated permeability class was compared with the measured rate. In case of discrepancy, the profile was re‐examined to see if any signfiicant clues had been overlooked. It was found that permeability could be estimated, with fair precision, from information obtained in the field, in terms of seven classes that are defined in terms of saturated percolation rates.The first step is determination of the type of structure. Then the class of permeability is estimated from four principal clues and one or more of eight secondary clues. Types of structure and structureless conditions found significant are fragmental, platy, nuciform, cubical blocky, prismatic, single grain, and massive. Principal clues are relative dimensions, horizontally and vertically, of structural aggregates; amount and direction of over‐lap of the aggregates; number of visible pores; and texture. Important secondary clues are compaction, direction of natural breakage, silt content, cementation, type of clay minerals, character of coatings on aggregates, degree of mottling and certain features of climate. None of these clues, when taken singly, is a reliable indicator of permeability, but each must be considered with reference to the others.
Effect of Increasing Fertilizer Concentration on Exchangeable Cation Status of Soils
Authors: Bear F. E. , Prince A. L. , Toth S. J. 
Published: July 2010

AbstractIn a 10‐year experiment, comparisons were made of the effects of fertilizers of 1‐2‐2 N, P2O5, and K2O ratios, applied at the rate of 1 ton of 4‐8‐8 an acre annually, or its equivalent in higher grades up to and including the 12‐24‐24, on the exchangeable cation status of two soils. The most significant general effects of all these grades were the lowering of pH values, increase in exchangeable H, reduction in exchangeable Ca and Mg, and increase in exchangeable K. There was little in the evidence to indicate any bad effects that could not readily be overcome by the use of Mg‐containing liming materials as correctives.
Readily Available Water in Forest Soils
Authors: Gaiser R. N. 
Published: July 2010

AbstractYear‐long records of soil moisture are reported for three forest soils of southeastern Ohio. Sustained maximum and minimum soil moisture levels are in close agreement with the moisture equivalent and permanent‐wilting percentage as determined in the laboratory and greenhouse. Data on the relationship of readily available water to soil texture are presented for soils of the Muskingum‐Wellston‐Zanesville association.Moisture losses from the soil through transpiration and evaporation during the 1951 growing season amounted to 13, 12, and 23 inches for the soils examined. The greatest loss was from Zaleski loam on a lower slope, and the smaller losses were from Wellston silt loam and Muskingum loam found on a ridge and upper slope. It is believed that moisture losses through evaporation from the soil proper are small and that the losses reported closely approximate the amount of moisture extracted for transpiration. The growth rate of white oak (Quercus alba L.) is considerably more rapid on the Zaleski loam than on the other soils.Because utilization of water is complete on the moist sites, it appears that the oak forests are capable of transpiring more water than is ordinarily available. In years of average precipitation, as much as 25 inches of water might be used in transpiration from trees and evaporation from all soil surfaces in the forest during the growing season. The remaining 15 inches of the average 40‐inch rainfall may be accounted for by evaporation, runoff, and deep seepage during the rest of the year.
Ethylene Glycol Retention by Soils as a Measure of Surface Area and Interlayer Swelling
Authors: Bower C. A. , Gschwend F. B. 
Published: July 2010

AbstractThe ethylene glycol‐retention method proposed by Dyal and Hendricks for determining interlayer swelling and the surface areas of clays has been modified for use on soils. The modified procedure is described. Data are presented showing that values for external surface area obtained by the ethylene glycol‐retention method agree satisfactorily with those obtained by the Brunauer‐Emmett‐Teller gas‐adsorption method. The effects of various exchangeable cations, organic matter and soluble salts upon ethylene glycol retention were studied. The nature of the exchangeable cation had no significant influence upon values obtained for external retention by soils. Total retention by calcium‐ and hydrogen‐saturated samples tended to be higher than that by sodium‐ and magnesium‐saturated samples. The lowest values for total retention were obtained on potassium‐ and ammonium‐saturated samples. The presence of organic matter increased values obtained for total retention. The apparent surface area of the organic matter in four soils varied from 558 to 803 sq. meters per gm. When calculated on a salt‐free basis, values for retention are not significantly affected by the presence of soluble salts.
Status Report on Soil Conditioning Chemicals. I.
Authors: Martin W. P. 
Published: July 2010

AbstractBecause of the short time the synthetic soil conditioners have been available for test, it is not possible to draw other than tentative conclusions. However, it appears fairly evident that they can effect marked improvement in the physical state of soils if properly applied. Rates of application of the order of 0.05% are such that at current prices the usefulness of these products in agriculture is likely to be limited to surface application with high value crops or for special purposes. It is not likely that they will constitute a replacement for, but will be an important supplement to sound agricultural practices. A sound body of information on which to base recommended procedures for the great variety of crops and soils found in the country at large is gradually accumulating because of the widespread interest of agronomists and others in this latest development from the field of chemistry.
Electrophoresis of Clays by the Schlieren Moving Boundary Procedure
Authors: Beavers A. H. , Larson B. L. 
Published: July 2010

AbstractElectrophoresis, as analyzed by the schlieren moving boundary system, has been used as a method for the study of the clay minerals. By the use of suitable buffers and standardized procedure for preparation, clay suspensions of sufficient concentration but of low opacity were prepared. Sodium veronal was found to be an effective dispersing agent for the hydrous mica‐like clays (Putnam and Cisne) and versenate and phosphate for the bentonite (montmorillonite) clays. It was found necessary to use the hydrogen clays dispersed in the appropriate buffer. Repeated attempts using the sodium clays gave suspensions unsuitable for electrophoretic analysis.The Putnam and Cisne subsoil clays were found to be either electrophoretically homogeneous or almost so in each of several buffer systems used, whereas the bentonite clays were found to be very heterogeneous. Artificial mixtures of the subsoil clays and the bentonite clays indicated that they could be separated electrophoretically since the subsoil clays possess mobilities slower than any of the bentonite components.Ultracentrifugal analysis of the Putnam clay indicated the presence of two major components. Since these did not show up on the electrophoretic patterns, it would seem to indicate that the electrophoretic entities are not due to differences in particle size.The pH and buffer concentrations were found not to materially affect the mobility of the clay systems.It would appear that further study of the electrophoretic properties of clays by the schlieren moving boundary system is warranted.
The Effect of Spring Nitrogen Fertilization on Plant Characteristics of Winter Wheat
Authors: Hobbs J. A. 
Published: July 2010

AbstractA study designed to determine the effect of nitrogen top‐dressing on plant characteristics, yield, and protein content of winter wheat was undertaken at Kansas State College in the spring of 1944. Nitrogen fertilizer was applied prior to March 15 to strips of winter wheat in the permanent fertility plots. Yield, protein content, and other data were collected from the top‐dressed and the untreated areas.The results indicated that spring applications of nitrogenous fertilizers increased the yield and also increased the protein content. The increases in yield were especially prominent on the plots which were adequately supplied with phosphate. Analysis of several plant growth characteristics indicated that much of this increase could be accounted for by increased tillering and by increased number of kernels per head. Other plant characteristics, such as kernel weight, had little, if any, effect on the increased wheat yields.
Some Observed Calcium Deficiencies in Corn under Field Conditions
Authors: Melsted S. W. 
Published: July 2010

AbstractTypical calcium deficiencies in corn obtained under field conditions are reported. The plants showing the typical deficiency symptoms contained less than 0.2% of calcium in the plant as a whole. The pH of the soils was less than 4.5, and the exchangeable calcium was less than 2 milliequivalents per 100 grams of soil. The deficiency was brought about by the addition of large amounts of nitrogen, phosphorus, and potash fertilizers to acid soils without correcting the acidity.
Influence of Forest Cover on the State of the Ground Water Table
Authors: Wilde S. A. , Steinbrenner E. C. , Pierce R. S. , Dosen R. C. , Pronin D. T. 
Published: July 2010

AbstractThe state of ground water level was determined in forested and cutover soils of central and northern Wisconsin by observations of open wells during the frost‐free periods. In nonpodzolic, coarse, sandy soils, ground water possesses considerable mobility, and forest cover effected only a slight lowering of the water level, not exceeding 9 inches. The influence of forest cover was most pronounced in the middle of the growing season; from October to May the water table occupied nearly a horizontal position. In strongly podzolized, morainic soils, however, clear cutting of aspen stands produced an average rise of 14 inches, and converted a reasonably well‐drained soil into a semiswamp. In the rainy spring and summer of 1952, this alteration of the ground water table was accompanied by increased run‐off, erosion, and damages to roads.
Effect of Sample Drying on the Determination of the Water‐stability of Soils
Authors: Slater C. S. 
Published: July 2010

AbstractWater‐stability analyses, to determine structural quality in soils, reflect field conditions only to the extent that the soil samples on which they are based remain unmodified (or are modified uniformly) by the treatment received between the times of sampling and analysis. Air drying of the sample is an accepted procedure. This paper reports the effects of air drying samples at different temperatures as indicated by the results of water‐stability analyses. It is concluded that if the samples are air dried at rates and temperatures that are characteristic of ordinary variations in laboratory conditions, the variations of stability so induced do not modify greatly the relative levels of stability represented by the samples. However, the induced variation was greater, over a temperature range of from 40°F to 180°F, than that between duplicate analyses.
Pressure Distribution in Layered Soils during Continuous Water Flow
Authors: Day Paul R. , Luthin James N. 
Published: July 2010

AbstractThe occurrence of a pressure deficiency (“tension”) in the liquid phase of flooded, freely drained soils has been observed in texturally stratified columns in the laboratory. This phenomenon has been explained in the following way on the basis of Darcy's law: If water flows downward through a soil layer at a rate which exceeds its hydraulic conductivity value, the loss of head by friction will exceed the energy supplied by gravity, and a pressure drop will occur along the path of flow.A moderately permeable surface soil over a highly permeable substratum presents an excellent opportunity for the development of tension in the soil during flooding operations. The practical implications of this fact are discussed with reference to water spreading investigations.
Cation Exchange in Soils Through the Moisture Range, Saturation to the Wilting Percentage
Authors: Brown D. A. 
Published: July 2010

AbstractData are reported to show the effect of soil moisture upon cation exchange in soils through the moisture range, saturation to wilting percentage, for seven soil series, including Lakeland, Ruston, Richland, Crowley, Sharkey, Houston, and Gila. Cation exchange resin membranes of known exchange capacity were saturated with the hydrogen ion and buried in 100‐gram aliquots of each of the above soil series. These aliquots of soil were moistened to cover the range, saturation to the wilting percentage, in a systematic manner. The membranes were allowed to remain in the soil for 96 hours, then removed, and the amounts of Ca, Mg, Na, and K exchanged to them from the soil measured quantitatively.The amounts of cations exchanged increased sharply as the soil moisture increased. The increase in cation exchange at saturation when based upon that exchanged at the moisture equivalent was 7 fold for Lakeland, 5 for Ruston, 2 for Richland, 3 for Crowley, but only a 0.2‐fold increase for Sharkey, Houston, and Gila series. The percentage decrease in cation exchange at the wilting percentage, when based upon the exchange at the moisture equivalent was 50, 65, 85, and 72 for Lakeland, Ruston, Richland, and Crowley, respectively, but only 14, 19, and 25% for Sharkey, Houston, and Gila, respectively. The suite of exchanged cations were significantly altered with increases in moisture.The percentage of Ca and Mg increased in the suite of cations, while that of K and Na decreased correspondingly as the soil moisture increased. The Ca:K ratio increased from 60 to 266 over the moisture range, wilting percentage to saturation, for the Houston series, 10 to 60 for the Richland series, but only 7 to 10 for the Lakeland series. The cation exchange‐moisture relationships are explained on the basis of the relative abundance and continuity of the water films within the pore system of the soil that may effectively serve as a medium for the diffusion of cations through the soil.
Zinc Status of Some Illinois Soils as Estimated by an Aspergillus Niger Method
Authors: Tucker T. C. , Kurtz L. T. , Lynch D. L. 
Published: July 2010

AbstractAn extremely sensitive semiquantitative method for bio‐assay of zinc in soils with Aspergillus niger is described. Data at present do not permit the validation of the assay as an index of response by higher plants on soils of Illinois. Present investigations are being conducted to locate soils that will respond to zinc fertilization. It is hoped that these studies will show a positive relationship between the bio‐assay of zinc in the soil and crop response, and perhaps lead to a chemical method which will appropriately measure the available form of zinc in soils. The method as outlined was used for acid soils and is not applicable to alkaline or calcareous soils.Although the procedure is relatively simple, extreme care must he exercised in order to prevent contamination with zinc from reagents and equipment. Reagent grade chemicals were used and purification of water and sucrose was effected by an ion‐exchange resin. An acid cleaning solution was the most effective method tried for removing traces of zinc from equipment. Sterilization of the soil to be assayed is not recommended.The growth response of Aspergillus niger was related to known increments of zinc in 50‐ml nutrient solution in 500‐ml Erlenmeyer flasks. This relationship was used to evaluate the zinc status of soils. Florida soils known to respond to zinc fertilization ranged from 0.6 to 2.88 ppm zinc and Illinois soils ranged from 1.6 to 21.5 ppm zinc, according to the bio‐assay. It is conceivable that a few Illinois soils may respond to zinc fertilization or are at least approaching a critical level.
Some Relationships between the Classification of Rocks by Geologists and the Classification of Soils by Soil Scientists
Authors: Whiteside E. P. 
Published: July 2010

AbstractA unified philosophy is presented of some of the basic relationships between the classification of rocks by geologists and the study of soils for students and teachers in these fields. These include the differentiation of rocks and soils, the definition of parent rock, and a suggested approach to the classification of parent rocks.The descriptive classification of igneous rocks by geologists is shown to be very useful to soil scientists, while their classification of sedimentary rocks has lagged behind the fundamental needs of pedologists. A summary of some of the basic contributions by geologists and soil scientists in this field is presented. It is hoped that the challenge of the past achievements and the current needs will stimulate further critical studies in these areas of mutual interest to geologists and pedologists.
Soil Erosion on Logging Roads
Authors: Trimble George R. , Weitzman Sidney 
Published: July 2010

AbstractIn rugged mountainous country, skid roads used in logging operations cause serious erosion. To determine the important factors in skid‐road erosion, and to find ways to reduce this erosion, sample skid roads were studied before, during, and after experimental logging operations on the Fernow Experimental Forest in West Virginia.Erosion was related to grade, length of slope, intensity of use, soil, vegetation, and climatic factors. Degree of erosion was determined for different skid‐road conditions.Measures for reducing erosion are recommended for use in locating, constructing, using, and maintaining skid roads. Drainage measures such as diversion ditches and water bars are essential. Spacings for water bars are recommended for different grades.
The Application of the Gouy Theory to Soil‐Water Systems
Authors: Bolt G. H. , Peech Michael 
Published: July 2010

AbstractThis paper shows how the Gouy theory may be used to describe the properties of soil and clay suspensions. The volume charge density and the potential distribution in a single layer may be calculated for widely different clay suspensions if the surface density of charge and the concentration of free electrolyte are known. The interaction between two diffuse double layers of adjacent particles leads to a differential equation describing the volume charge and potential distribution that can be solved only for suspensions containing symmetric electrolytes. Sufficiently accurate approximations of the charge and potential distribution may be made, however, for suspensions containing asymmetric electrolytes. Due consideration must be given to the specific adsorption potential of ions in the Stern layer. By means of the Gouy theory it is possible to calculate such measurable quantities as negative adsorption, osmotic pressure, and membrane potential. A comparison of the applicability of the Donnan and the Gouy theories shows that the Gouy theory is superior in describing and predicting the properties of deflocculated clay suspensions. Indeed, the application of the Donnan theory to such systems leads to serious errors.
The Significance of Potentiometric Measurements Involving Liquid Junction in Clay and Soil Suspensions
Authors: Peech Michael , Olsen R. A. , Bolt G. H. 
Published: July 2010

AbstractA critical study has been made of the behavior of the liquid junction between the saturated KCl and the clay or soil suspension in attempt to evaluate the sign and the magnitude of the junction potential in measurements of membrane potentials and ion activities. In deflocculated suspensions of clay saturated with monovalent cations, the saturated KCl in the salt bridge short‐circuits the potential drop across the diffuse double layer and thus exaggerates the magnitude of the membrane potential or the ion activity of the clay suspension predicted by the Gouy theory. In suspensions of Ca‐clay and most soils, however, the effect of short‐circuiting the small potential drop across the diffuse double layer is more than offset by the diffusion potential due to CaCl2 that is formed ahead of the KCl diffusion front. The sign of this diffusion potential is such as to decrease the magnitude of the membrane potential or the ion activity of the clay suspension. Comparison of the observed osmotic pressure of clay suspensions with that calculated according to the Gouy and the Donnan theories fully confirmed the conclusions reached from the potentiometric data concerning the sign and magnitude of the liquid junction potential.
Increased Color Stability in the Determination of Magnesium
Authors: Yien C. H. , Chesnin Leon 
Published: July 2010

AbstractThe method of Drosdoff and Nearpass was modified for the determination of magnesium in plant and soil extracts. One method is proposed for the analysis of ammonium acetate extracts of soils, and another method is proposed for the analysis of plant materials and water extracts of soils. These methods, which determine the magnesium content colorimetrically with the use of thiazole yellow, introduce the use of sodium bisulfite to stabilize the color obtained. Polyvinyl alcohol is used to obtain suspension stability. A procedure for the determination of magnesium with titan yellow is also presented.A number of soil and plant samples were analyzed by the A.O.A.C. method, the proposed methods, and the method of Drosdoff and Nearpass. Values obtained for the magnesium content of the soils and plants indicate greater accuracy and reproducibility of duplicate determinations by the modified procedures than by the Drosdoff‐Nearpass method. The modified methods are more sensitive to changes in magnesium concentration than is the Drosdoff‐Nearpass method. Color stability of 24 hours have been obtained with the titan yellow procedure and the method used for plant analysis, and one hour of color stability has been obtained with the method used for determining exchangeable magnesium. The proposed procedures are rapid, accurate and reproducible. Stability of color and suspension, and facility of the methods adapt these procedures to mass routine analysis of samples for magnesium.