bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical and Mineralogical Properties of Glauconitic Soil as Related to Potassium Depletion
Authors: El‐Amamy M. M. , Page A. L. , Abudelgawad G. 
Published: July 2010

AbstractThe mineral glauconite has been identified in parent materials of some Libyan soils in the Barce Plateau region. Three soils, Elabiar clay loam, Elmarj silty clay, and Hamama clay, were selected to represent a weathering sequence. The cation exchange capacities (CEC) of these soils were found to increase with increased weathering intensity. This study dealt with the effects of potassium (K) depletion from clay and silt fractions on chemical and mineralogical properties of the soil glauconite. A relationship between equilibrium K concentration in the extracting solution and weathering degree was established.Although it existed in all size fractions, glauconite (10.0, 5.0Å) was found in higher concentrations in fine silt and coarse clay fractions. Elabiar clay loam contained more glauconite and less K‐depleted glauconite than Hamama clay. Total K values were proportional to the amount of glauconite in each of the soil separates.The results of equilibrating the clay and silt fractions with 1N NaCl indicated that more than 90% of total K was exchangeable with an equivalent increase in CEC. When the replaced K was allowed to accumulate in the extracting solution, the exchange process continued until K concentration reached a certain equilibrium level. The equilibrium K concentration was a function of K depletion regardless of particle size, solution density, or both. Because of their larger surface areas and the shorter diffusion paths, the finer fractions had shorter equilibration times and more rapid exchange rates.The K depletion resulted in expanding the 10Å glauconite to 14 to 15Å when Mg‐saturated. Glycolation of the Mg‐treated samples did not effect the 14 to 15Å K‐depleted mineral. The results confirm those of previous research with glauconite specimens that, upon weathering, the soil glauconite produced a vermiculite‐ rather than a smectite‐type mineral.
Heavy Water Tracing of Soil‐Water Transfers Under Irrigation
Authors: Moutonnet P. , Couchat Ph. 
Published: July 2010

AbstractIn soil columns, a horizon was labeled with heavy (deuterated) water (D2O), and the evolution of D2O during the experiment was monitored in situ by gamma‐neutron counting. An automatic irrigation device was used for crop watering.Based on the results of two consecutive experiments (H2O and D2O balance and water transfer analysis), the system was found to provide fully satisfactory irrigation. Deuterated water labeling, moreover, proved to be an effective technique for evaluating root uptake in a soil horizon.
Salt Generation in Pyritic Coal Spoils and its Effect on Saturated Hydraulic Conductivity
Authors: Evangelou V. P. , Phillips R. E. , Shepard J. S. 
Published: July 2010

AbstractThe oxidation of pyrite (FeS2) in surface‐mined coal spoils usually generates a large amount of soluble salts. These salts may impede water movement through the spoil, in some cases due to an increase in soil solution viscosity. This hypothesis was tested by the use of an 8.9‐cm diameter column filled with spoil material and outfitted with six tensiometers at 14‐cm intervals along its length. The buildup of salts in the lower portion of the column due to oxidation of pyrite was correlated with a suppression in hydraulic conductivity. A gradient in saturated hydraulic conductivity was measured starting in the upper portion of the column with a value of 0.50 cm/hour, decreasing to 0.03 cm/hour in the lower portion of the column. A gradient of salts was also encountered, with an electrical conductivity at the top of 0.12 mmho/cm and at the bottom of 16.44 mmho/cm. Upon depleting the salts from the column the saturated hydraulic conductivity of the lower portion approached that of the upper portion.
Effect of Soil Cation Exchange Capacity on the Uptake of Cadmium by Corn
Authors: Hinesly T. D. , Redborg K. E. , Ziegler E. L. , Alexander J. D. 
Published: July 2010

AbstractSince many investigators examine the environmental input of sludge‐borne heavy metals through studies involving soluble metal salts, it is imperative that the equivalence of these two metal sources be tested.Samples of B1 horizon of the Ava series (Typic Fragiudalfs) and Ap horizon of Maumee series (Typic Haplaquolls) were separately diluted with samples of the Plainfield series (Typic Udipsamments) to obtain soil mixtures having cation exchange capacities (CEC) of about 5.3, 10.6, and 15.9 meq/100 g. A mixture containing equal proportions of Ava and Maumee were also diluted with Plainfield to give an equivalent range of CEC. One portion of each of the nine experimental soils was admixed with the equivalent of 100 metric tons/ha of dried, digested sewage sludge to provide soil‐Cd concentrations of 10 mg/kg. The remaining portion was treated with CdCl2 at rates to provide equivalent soil‐Cd concentrations.Corn (Zea mays L.) (single‐cross Mo17 × H98), selected for its inherited capacity to take up relatively high amounts of Cd, was planted in four pots of each mixture. Three plants were harvested at the end of 3 weeks and an additional three after 7 weeks. Cadmium uptake and dry weight production were affected to the greatest extent by Cd source > soil or soil mixture > CEC. Cadmium uptake and plant yields were inversely related to CEC on CdCl2‐treated soil but were not significantly different on soil mixtures treated with sludge. Less cadmium was taken up from soil mixtures that contained increasing quantities of Maumee, but there was no evidence that organic matter decreased cadmium uptake beyond that attributable to increased CEC. Total amounts of cadmium accumulated per plant were significantly different on sludge‐treated mixtures, but the magnitude of the differences were small compared to those from CdCl2‐treated soils. Biomass produced during the interval between the first and second harvest contained less cadmium than that collected during the first harvest. For the most extreme example (Ava B1 treated with CdCl2), only slightly more than 2% of the total soil cadmium was depleted by corn plants during 7 weeks of growth.
Soil Pore Structural Stability and Irrigation Water Quality: II. Sodium Stability Data
Authors: Cass A. , Sumner M. E. 
Published: July 2010

AbstractThe effect of mixed sodium/calcium solutions on the hydraulic conductivity (HC) of a range of soils was measured at fixed sodium absorption values and a range of cation concentrations decreasing from 800 to about 1 meq/liter. A similar series of solutions was used to measure water uptake (macroscopic swelling) of extracted soil clays. Using these data, sodium sensitivity and threshold swelling models were computed. The slope of the sodium sensitivity model was related to the smectite content, cation exchange capacity, and specific surface of pedal, nonvertisol soils through log‐log relationships having correlation coefficients of 0.67*, 0.61**, and 0.66**. It was also related to swelling by a log‐linear relationship (r = 0.64*). Some vertisols did not obey these relationships, possibly because of the effect of marked alteration to flowbed geometry during swelling. Such alteration maintained HC at higher values than would have been inferred from soil properties alone. Apedal soils containing large amounts of smectite also displayed greater stability than expected, possibly because of the stabilizing effect of sesquioxides on clay swelling. Soils with low specific surface, low CEC, and little smectite and/or sufficient sesquioxide to inhibit swelling (red, apedal) tend to be most stable in the presence of mixed Na/Ca solutions.
Kinetics of Thermal Dehydration of Gypsiferous Soils
Authors: Elprince A. M. , Al‐Shammary M. A. , Magboul A. M. 
Published: July 2010

AbstractRecording the decrease in weight with time upon heating by electrically reproducible infrared (IR) radiation offers a fast method for studying the kinetics of the dehydration of gypsiferous soils. Plotting the weight loss rate against time gives a dehydration curve made of two peaks. The first peak is due to soil moisture and the second to the crystal water of gypsum. The product of dehydration is best regarded as soluble anhydrite (CaSO4 · ε H2O) rather than hemihydrate (CaSO4 · ½H2O) or insoluble anhydrite (CaSO4). This is indicated by the loss in weight and the IR spectra. The kinetic curves for the dehydration of gypsum at 156, 123, and 95°C are of sigmoidal forms. Beyond the inflexion point, most of the data fits the “diminishing sphere” kinetics formula. The rate constants and activation energies for the interface advance process shows that the soil matrix acts as a catalyst and that Na montmorillonite is a more effective catalyst than the soil matrix. A rate‐limiting step for the interface advance is the necessity for crystal water to pass through an adsorbed state. Soil minerals may offer effective adsorption sites. In contrast to the growth process soil matrix is a more effective catalyst for nucleation than Na montmorillonite.
Effect of Suspending Agent and Temperature on Survival of Rhizobium in Fertilizer
Authors: Kremer R. J. , Polo J. , Peterson H. L. 
Published: July 2010

AbstractThe lack of compatibility between legume inoculants and fertilizers has been widely recognized and reported. Studies involving alternative inoculant carriers and methods of inoculant preparation led to an examination of rhizobia incorporation in fertilizer. The effects of suspending agent and incubation temperature on the survival of two strains of Rhizobium in 0‐9‐12 fertilizer were determined using plate counts and most‐probable‐number methods of analyses. Results showed that oil was superior to water in maintaining the viability and effectiveness of two strains of lyophilized rhizobia. A fertilizer incorporated with lyophilized R. phaseoli suspended in oil contained nearly 104 viable cells per gram after 24 weeks of incubation at 65°C. In contrast, no R. phaseoli were recovered from a fertilizer containing a water suspension of lyophilized cells after 8 weeks of incubation at 25°C. These results strongly suggest that fertilizer and lyophilized rhizobia may be combined to form an effective inoculant if adequate precautions are taken to protect the rhizobia from rehydration.
Nodulation of Crimson Clover by Introduced Rhizobia in Mississippi Soils
Authors: Materon L. A. , Hagedorn C. 
Published: July 2010

AbstractCrimson clover (Trifolium incarnatum L.) has long been recognized as an important annual legume in the winter grazing programs of the South. Considerable effort has been devoted to the development of cultivars which are resistant to disease, reseed reliably, and produce more fall and winter forage. Little information on the bacterial microsymbiont has been reported, and questions exist which concern Rhizobium strain‐host cultivar interactions, persistence of inoculum strains, and nitrogen fixation rates under field conditions. For this reason, five strains of R. trifolii were evaluated in competition with indigenous populations in nodulating crimson clover at two field sites in Mississippi. Proportions of nodules due to the introduced strains were measured by acquired and intrinsic antibiotic resistance. First season data indicated significant differences among the amended strains both within and between field locations. Three of the strains (162K10, RP113‐14, and RP111‐51) were recovered at a high frequency (>85% of the nodules sampled) in one site. At the second location, almost one‐half of the nodules assayed were produced by the indigenous rhizobia when competing with 162K10 and RP113‐14. In contrast, the proportion of nodules due to the other two strains, a local isolate (207) and an Australian culture (TA1), varied between 16 and 55% at both locations. Forage yield and percent crude protein levels reflected a positive association with the most competitive Rhizobium strains. These results indicate that selections for highly effective and adaptive Rhizobium strains can increase both crimson clover production and symbiotic nitrogen fixation.
Soil—Landscape Relationships in the Piedmont of Maryland
Authors: Darmody R. G. , Foss J. E. 
Published: July 2010

AbstractA study was conducted to investigate and model the soil‐landscape relationships in the Piedmont of Maryland. The soil series of particular interest were the Chester, Glenelg, and Elioak series of Typic Hapludults. Results indicate that Elioak soil is a relict paleosol. A stone line separating strongly weathered Elioak soil material from silty overburden was revealed in several excavations. Particle‐size analyses and elemental analyses of silt fractions confirmed these discontinuities. Comparisons with known and radiocarbon‐dated loess deposits on the eastern shore of Maryland indicate that the silty overburden on the Piedmont is loess which was deposited after 10,520 ± 240 years B. P. Where the loess is thick, as on gentle slopes, Chester soils are mapped. Where the relict paleosol has been essentially eroded away, as on steeper slopes, Glenelg soils are mapped.
Estimation of the Concentration of Fe3+ and the (Fe3+)(OH‐)3 Ion Product from Equilibria of EDTA in Soil
Authors: Norvell W. A. , Lindsay W. L. 
Published: July 2010

AbstractEquilibria of EDTA (ethylenediaminetetraacetic acid) chelates were used to measure the concentration of ferric ion in near‐neutral soils. Concentrations of Fe3+ and the (Fe3+)(OH‐)3 activity product were defined quantitatively by simultaneous equilibria involving EDTA4‐, Fe3+, Ca2+, and OH‐. Equilibrium between soil Fe and chelated Fe was established by varying the fraction of EDTA associated with Fe or by slightly altering the pH of the soil. Corrections were made to account for the differential sorption of various EDTA chelate species onto soils and for the formation of EDTA chelates of Zn and Cu.Concentrations of Fe3+ in the range of 10−16 to 10−18 M were measured successfully in the presence of much higher concentrations of iron present as hydrolysis species and as unknown natural complexes. In 10 experiments using three near‐neutral soils, the negative logarithm of the (Fe3+)(OH‐)3 ion product had a mean value of 39.3 with a standard deviation of approximately 0.2. The solubility of Fe3+ in equilibrium with soil was stable for at least 6 weeks.
Conversion of Freundlich Adsorption K Values to the Mole Fraction Format and the Use of SY Values to Express Relative Adsorption of Pesticides
Authors: Bowman B. T. 
Published: July 2010

AbstractAnomalies in the Freundlich isotherm equation prevent the simple conversion of K values to a common set of units for assessment of relative adsorption. Although there is a straightforward way to properly convert the units of K values, serious extrapolation errors can result because, in the new set of units, the K value may be evaluated considerably outside the concentration data range. In the mole fraction format, concentration is reported as a mole fraction, and adsorption as mol g−1, giving units of mol g−1 for K. In this format, K loses any practical meaning since it is evaluated at log Z = 0, Z = 1. An improved and more flexible method of reporting relative adsorption using SY values is presented as well as a procedure to convert existing data to this format.
A Comparison of the Effects of Monocalcium Phosphate and Diammonium Phosphate on Phosphorus and Calcium Availabilities
Authors: Adams Fred 
Published: July 2010

AbstractBecause monocalcium phosphate (MCP) is often a superior phosphorus (P) source to diammonium phosphate (DAP) when used at high rates, a short‐term, growth‐chamber experiment was conducted to compare the two P sources. An acid, P‐deficient Lucedale sandy loam (Rhodic Paleudult) was treated with all combinations of five lime rates and four P rates (0, 75, 150, and 300 ppm) as MCP and DAP. Other needed nutrients and a nitrification inhibitor were uniformly added, and a sorghum‐sudangrass hybrid (Sorghum bicolor × S. sudanensis L.) was grown for 14 days. Soil pH was lower and soil‐solution P and Ca were higher from MCP than DAP at each P rate. Several DAP‐treated soils produced forage yields lower than that predicted from their P levels; the lower yields were positively correlated with lower soil‐solution Ca. The critical ambient Ca level in DAP‐treated soil was significantly lower for plants growing at the rate of 300 ppm P than at that of 150 ppm, possibly because high P levels enhanced the uptake or physiological utilization of Ca.
Parameters for Describing Soil Detachment Due to Single Waterdrop Impact
Authors: Al‐Durrah M. M. , Bradford J. M. 
Published: July 2010

AbstractA simple relationship that predicts soil detachment due to single raindrop impact was tested for nine soils and three drop sizes. This relationship expressed splash weight as a linear function of the ratio of raindrop kinetic energy to soil resistance expressed as the undrained shear strength. The coefficient of determination values between splash weight and the force‐resistance ratio for individual soils were high (r2 = 0.88 to 0.97); however, the coefficient of determination among all soils was lower (r2 = 0.81). This was due to differences among soils in the slope of the regression line and to uncertainties associated with the calibration of the fall‐cone penetration apparatus. The slope was highly correlated with percent clay, organic matter, surface area, exchangeable sodium, and the amount of soluble salts. A maximum coefficient of determination of 0.61 was found when soil properties other than shear strength were used as independent variables to predict soil splash.
A Permeameter Which Eliminates Boundary Flow Errors in Saturated Hydraulic Conductivity Measurements
Authors: Hill R. L. , King L. D. 
Published: July 2010

AbstractA permeameter was designed to eliminate boundary flow errors that occur during saturated soil hydraulic conductivity measurement. Advantages of the permeameter are its adaptability for use with either disturbed or undisturbed soil samples, the elimination of possible problems associated with acrylic swelling, and relatively low cost. The permeameter was effective in eliminating boundary flow errors.
Control of Nickel and Strontium Sorption by Free Metal Ion Activity
Authors: Bowman R. S. , O'Connor G. A. 
Published: July 2010

AbstractFormation of soluble complexes usually lowers sorption of metals by soils. The purpose of this study was to determine if changes in free Ni2+ or Sr2+ activity could explain differences in isotherms obtained in highly complexing SO2‐4 systems vs. slightly complexing Cl‐ systems. Sorption of Ni and Sr by homoionic montmorillonite and soil was studied using the batch isotherm technique. The Na+ (0.1N) and Ca2+ (0.02N) solutions of Cl‐ and SO2‐4 with Ni or Sr (10−6 to 10−4M) yielded systems in which up to 45% of soluble metal (M) was present as MSO04. Sorption was greater in the Cl‐ vs. the SO2‐4 systems at the same total M (Ni or Sr) concentration at equilibrium. Plotting data in terms of free M2+ activity at equilibrium eliminated significant differences between corresponding isotherms. Sorption thus appeared to be controlled by M2+ activity. The data supported the hypothesis that MSO04 complexes were not sorbed and MCl+ complexes sorbed only slightly if at all. Nickel sorption was greater than Sr sorption under similar conditions. The results illustrate the importance of correcting for ionic strength/ion pairing effects before making comparisons among isotherms.
Mineralization and Plant Availability of Phosphorus from Biomass of Hyaline and Melanic Fungi
Authors: Kapoor K. K. , Haider K. 
Published: July 2010

AbstractThis study was conducted to evaluate the mineralization and phosphorus availability to plants from fungal biomass and to determine differences between hyaline and melanic fungi in this respect. In a period of 5 weeks, wheat plants took up 6 to 16% of applied 32P in the form of fungal mycelia from soil. The availability of P from this biomass was lowest with highly melanized fungi Curvularia lunata and Stachybotrys chartarum (6 to 11%) and highest in the case of hyaline fungi Paecilomyces fusisporus and Penicillium chrysogenum (12 to 16%). This compared to >20% uptake of applied inorganic phospate. Carbon mineralization of fungal biomass during a 5‐week‐incubation period decreased with increase in melanization. Phosphorus availability to plants followed C mineralization but the correlation was not highly significant. Sixty to 70% of the P from fungal biomass was extractable with sodium bicarbonate predominantly in an organic form. Plant availability of this extractable organic P was lower in the case of melanized fungi than in hyaline.
Atmospheric Sulfur as Related to Acid Precipitation and Soil Fertility
Authors: Suarez E. L. , Jones U. S. 
Published: July 2010

AbstractIn experiments conducted to determine the major acidic components of precipitation in the southeastern United States, amounts of sulfur (S) deposited on the soil with rainfall were estimated and relationships between applied sulfur and crop yields in South Carolina were established.Precipitation was collected at three locations from 10 Apr. 1979 to 8 Apr. 1980, at Clemson, S. C., Experiment, Ga., and Franklin, N. C., using a wet/dry collector. Conductivity, pH, and ionic components were determined in the rainfall and particulate matter. Sulfur in the air was collected at Clemson on a 30‐d interval in a standard lead peroxide sampler. Soil samples were taken from 15 locations in South Carolina and analyzed for sulfur.It was observed that the average loading concentration of anions in rainwater increased during the spring‐summer months and decreased during the fall‐winter months. Sulfuric and nitric acids were found to be the major components of acid rainfall. Rainfall and air deposition contributed approximately 10.7 and 1.8 kg/ha of sulfur per year, respectively, at Clemson. Atmospheric deposition from the particulate matter contributed an estimated 3.0 kg/ha of sulfur during the year.Increases in corn grain and silage yields were obtained with the application of 18 kg/ha of sulfur at Darlington, S. C. A relationship between applied sulfur and crop response for the other crops considered could not be established. A need for reevaluating the findings and recommendations for sulfur fertilizers was apparent because of the contribution of atmospheric‐deposited sulfur to the soil and plant sulfur supply.
Toxicity of Aluminum to Coffee Seedlings Grown in Nutrient Solution
Authors: Pavan Marcos A. , Bingham F. T. 
Published: July 2010

AbstractA solution culture experiment was conducted with coffee seedlings (Coffea arabica L.) to determine the combined effect of ionic strength and aluminum (Al) concentration of nutrient solutions on Al availability. The treatments consisted of three Al concentrations: 0.0, 0.037, and 0.148 mmol dm−3. These were combined with five levels of ionic strength produced by diluting a complete nutrient solution to relative concentrations of 0.5, 0.25, 0.10, and 0.01. The phosphorus (P) concentration of each solution was adjusted to 0.1 mmol dm−3. The pH of the solutions was maintained at 4.0 ± 0.2. Shoot and root growth decreased progressively under the Al treatments. The lateral roots of Al‐stressed plants were thicker, shorter, and fewer in number than those of the control plants. The younger leaves of Al‐stressed plants were small, curled along the margins, and frequently chlorotic along the leaf margin.At a constant Al concentration, seedling growth was reduced with dilution of the nutrient solution. This decrease in growth was best correlated with an increase in the activity of Al3+. An Al3+ activity value of 1.2 × 10−5 was associated with a 10% reduction of coffee seedling growth.