bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anomalies in Techniques for Preparing H‐Bentonites
Authors: Aldrich D. G. , Buchanan J. R. 
Published: July 2010

AbstractVarious procedures for the preparation of H‐bentonites to be used in physical‐chemical studies of clay systems have been examined. Their effects upon the exchangeable H and Al content of these bentonites have been evaluated by titration curves and chemical analyses.A procedure for reducing the amount of exchangeable Al in such preparations is proposed. This procedure involves pretreatment of the bentonite suspension with hydrochloric acid and sodium chloride solutions followed by removal of excess electrolyte and passage of the suspension through an H‐resin column.The exchangeable H and Al status of bentonites thus prepared is discussed.
Determination of Organic Phosphorus in Soils: III. Comparison of Methods
Authors: Van Diest A. , Black C. A. 
Published: July 2010

AbstractKaila and Virtanen found that in most of the soils they analyzed for organic phosphorus they obtained a higher figure with an extraction method they proposed than with the extraction method proposed earlier by Mehta and coworkers. Analyses of samples of five soils by the authors showed that the Mehta method yielded more organic phosphorus than the Kaila‐Virtanen method in all five samples.
Investigation of a Thermal Method for the Determination of Fixed Potassium in Soils
Authors: Legg J. O. , Axley J. H. 
Published: July 2010

AbstractThe release of K from soils according to the thermal method proposed by Kolterman and Truog was studied. This method involves heating an NH4‐saturated sample at 500°C. for 2 hours, followed by extraction of the K made exchangeable with ammonium acetate. The proponents of this method found that successive treatments released K from certain soils and clay minerals in a definite manner such that the slope of the lines formed by plotting the log K released against the treatment number was constant for all of the materials tested. The assumption that the slope would remain constant for all soils permitted the calculation of the total amount of fixed K from the results of only one or two heating and extraction treatments.A group of soils with known K release characteristics was subjected to six successive heating and extraction treatments. The release of K from the different soils did not follow the expected pattern, however, since the slope of the log K plots did not remain constant for all soils. This discrepancy invalidates the method of calculating the total fixed K in the soil as proposed by Kolterman and Truog.The data suggest the possibility of using the thermal method for determining the relative capacity of soil to supply nonexchangeable K to plants. A single heating and extraction treatment was as effective as a series of successive treatments in this regard.Potassium release characteristics of a number of Maryland soil profiles were also studied by means of the thermal method. Potassium released by successive treatments varied greatly among soils and among horizons of each soil profile.
Nitrification in Grassland Soils
Authors: Soulides D. A. , Clark Francis E. 
Published: July 2010

AbstractNitrification studies were made on seven paired soil samples representing closely adjacent grassland and intertilled sites in the following soils: Codorus silt loam, Bladen clay loam, Cecil sandy loam, Hixton fine sandy loam, Fayette silt loam, Honeoye silt loam, and Pachappa sandy loam. All samples were incubated unamended and with 0.1% urea for periods of 2, 4, 6, and 9 weeks. Determinations were made for ammonia, nitrite, and nitrate nitrogen, and for urea nitrogen when indicated.Grassland samples of the Codorus and Bladen soils, pH 4.7 and 4.9, respectively, showed accumulations of ammonia when incubated unamended. Such accumulations were not apparent in the five remaining grassland samples ranging in pH from 5.7 to 7.9. All grassland samples, irrespective of pH, when amended with 0.1% urea showed higher retention of ammonia and lesser nitrate production than did their intertilled counterparts. Urea‐amended soils initially alkaline or becoming alkaline following addition of urea showed nitrite accumulation, irrespective of whether the samples came from grassland or intertilled sites. Soils showing nitrite accumulation showed greater nitrogen deficits than did the remaining soils. Greater nitrogen deficits were commonly encountered in the grassland than in the intertilled members of paired, urea‐treated samples. There appeared a direct relationship between nitrite accumulation and magnitude of nitrogen deficit.
Response of Coniferous Seedlings to Soil Applications of Calcium and Magnesium Fertilizers
Authors: Voigt G. K. , Stoeckeler J. H. , Wilde S. A. 
Published: July 2010

AbstractConiferous seedlings and transplants growing in two nurseries located on coarse sandy soils in northern Wisconsin showed intense yellowing of the outer portions of needles or, in severe cases, the entire foliage. This condition was accompanied by a greatly reduced rate of growth. Greenhouse and sample plot trials revealed that the yellowing was caused by acute deficiency of both calcium and magnesium in available or exchangeable form. The results of soil and foliar analyses suggested antagonistic interrelationships between calcium and magnesium and potassium. The normal color and rate of growth of seedlings were restored by application of 1 ton per acre of dolomitic limestone. A similar effect was produced by rototilling a 6‐inch topdressing of leaf mold from a productive hardwood‐coniferous stand.
Water Vapor Transfer in Dry Soil
Authors: Hanks R. J. 
Published: July 2010

AbstractWater vapor transfer in three dry soils was measured. The influence of porosity and depth of dry soil was investigated. Measurements were made primarily under isothermal conditions. Some measurements were made on one soil under nonisothermal conditions where the samples were radiated with a heat lamp. Liquid water movement was eliminated as a factor by treating the soil with a chemical water repellent.Calculations of water vapor transfer based on simple diffusion were made. The ratio of measured to calculated values was 1.38 for the Ladysmith silty clay loam, 1.32 for the Geary silt loam, and 1.04 for the Sarpy fine sandy loam. Porosity and depth of dry soil had no measurable influence on the ratio of measured to calculated values. This suggests that diffusion is the primary process involved.The ratio of the measured to calculated values for the Geary silt loam was 1.23 for the radiated samples. This is slightly less than the ratio measured for isothermal conditions which, considering the errors involved, indicates that simple diffusion theory is approximately correct for water vapor transfer in dry soil under both isothermal and nonisothermal conditions.
Separation and Determination of Total Copper and Zinc in Soils
Authors: Pratt P. F. , Bradford G. R. 
Published: July 2010

AbstractProcedures for the anion‐exchange separation of Cu and Zn from each other and from other elements, including Fe, are described. An aliquot of soil extract containing Fe in the ferric form and sufficient HCl to make 3M HCl is added to the resin columns, and the columns are washed with 3M HCl to remove ions that do not form or that form weak negative chloride complexes in HCl. The Cu is then eluted with 3M HCl. Ferric‐Fe, which moves slowly in the 3M HCl, is eluted with 1M HCl, after which the Zn is eluted with 0.001M HCl. The Cu and Zn are determined colorimetrically by the use of zincon (2‐carboxy‐2'‐hydroxy‐5'‐sulfoformazylbenzene).The separation and determination of Cu and Zn by these procedures give values in good agreement with dithizone extractions and determinations. The advantages of the new procedures are their simplicity and rapidity. Digestion with HClO4 does not completely dissolve Zn from soil samples.
Yield and Quality of Pangolagrass and Bahiagrass as Affected by Rate and Frequency of Fertilization
Authors: Engibous J. C. , Friedmann W. J. , Gillis M. B. 
Published: July 2010

AbstractField studies were carried out to determine the effect of rate and frequency of fertilization, primarily nitrogen, on the total production of forage and crude protein of Pensacola Bahiagrass and Pangolagrass under central Florida conditions, and to estimate their persistence under conditions of high fertility.The optimum nitrogen fertilization rate for Bahiagrass over the 5‐year period was 240 pounds per acre applied in 2 applications per year. Bahiagrass was damaged by single applications of greater than 240 pounds of nitrogen. The data showed that 200 pounds each of P2O5 and K2O represented more than adequate levels of these nutrients. There was no benefit from split application of phosphorus and potassium, which were applied at 200 pounds (oxide basis) per year.Pangolagrass responded to higher levels of nitrogen application—the optimum level was 320 pounds of nitrogen per acre per year. This grass can tolerate single applications of nitrogen up to 480 pounds per acre. In terms of forage or protein production, there was no advantage in split applications of nitrogen.
Molybdenum Response of Alfalfa on Indiana Soils in the Greenhouse
Authors: Foy C. D. , Barber S. A. 
Published: July 2010

AbstractGreenhouse experiments were conducted to determine the response of alfalfa to Mo on Indiana soils.Twenty‐five soils, representing 18 soil types from the major soil areas of Indiana, were used. The pH of the soils ranged from 4.8 to 7.4. Treatments included combinations of no lime; 250 pounds of CaCO3 per acre, mixed with the surface inch of soil; limed according to soil test; no Mo; and 2 pounds of Mo per acre. Three cuttings of alfalfa were obtained.Mo produced significant yield increases on 9 of the 18 soil types studied, and 7 others gave responses approaching significance. A significant response to Mo was obtained at the high rate of lime on 2 soils, and on 6 other soils increases were obtained which approached significance. This suggests a deficiency of total Mo in these soils. Mo treatment reduced alfalfa yields on 3 of the acid soils which received the high rate of lime and on I soil having an initial pH of 7.0.Results with one soil indicated that drying prior to cropping increased the response to Mo.
Chernozems and Associated Soils of Eastern North Dakota: Some Properties and Topographic Relationships
Authors: McClelland J. E. , Mogen C. A. , Johnson W.M. , Schroer F. W. , Allen J. S. 
Published: July 2010

AbstractChernozems may be associated with Humic‐Gley soils, Calcium Carbonate Solonchaks and Regosols and, less commonly, with solonetzic soils. The morphology of these soils, particularly of the Chernozems and Calcium Carbonate Solonchaks, is discussed. Some chemical and physical data are presented.
Fragipan Soils of Illinois: II. Mineralogy in Reference to Parent Material Uniformity of Hosmer Silt Loam
Authors: Grossman R. B. , Stephen I. , Fehrenbacher J. B. , Beavers A. H. , Parker J. M. 
Published: July 2010

AbstractThe mineralogy of Hosmer silt loam, a bisequal soil with a fragipan, was investigated in order to determine whether there is a lithological discontinuity between the parent material of the upper and lower sequum.Differences observed between the two sequa in respect to the mineralogy of the heavy and light, silt‐size fractions may be accounted for by a progressive decrease in the weathering intensity with depth and are not suggestive of a lithological discontinuity in parent material. The clay mineralogy for the B horizons of the two sequa was similar for the < 0.2µ and the 0.2µ to 2.0µ fractions, taken individually. However, for the total clay fraction, a higher percent of montmorillonite was found in the B′2 horizon of the lower sequum; this may be explained on the basis of illuviation.
Constancy of the Sum of Mica Unit Cell Potassium Surface and Interlayer Sorption Surface in Vermiculite‐Illite Clays
Authors: Mehra O. P. , Jackson M. L. 
Published: July 2010

AbstractThe total unit cell planar specific surface was computed as the sum of planar sorption surface (by a glycerol gravimetric method) and the mica unit cell interplanar surface (corresponding to the K). This sum was found to be constant for a given unit cell formula weight, averaging 773 m.2/g. with a standard deviation of ±12.7 or about ±2%. For example, a Colorado vermiculite had 1.63% K2O equivalent to 16.3% mica residue with a unit cell interplanar surface of 124 m.2/g.; this added to the measured 631 m.2/g. of planar sorption surface (glycerol sorbed on expanded or cleavage planes) gives a total planar surface of 755 m.2/g. Similarly, for coarse clay from Fithian, Illinois, the 5.61% K2O is equivalent to 56.1% of illite, with unit cell interplanar surface of 426 m.2/g. This, added to 235 m.2/g. of measured planar sorption surface, gives a total of 661 m.2/g. which when corrected to exclude 15% unexpanded minerals (kaolinite and chlorite) gives a total planar specific surface of 775 m.2/g. Wyoming montmorillonite had 803 m.2/g. of planar specific surface, comparing well with the theoretical, 808 m.2/g. This principle of unit cell planar specific surface constancy of 2:1 layer silicates shows that the mechanism of K release from mica is by cleavage, and gives an accurate tool for analysis of the rather generally occurring interstratified mixtures of expanding 2:1 layer silicate minerals with micas in soils and sediments.
Solutions of the Flow Equation for the Drying of Soils and Other Porous Media
Authors: Gardner W. R. 
Published: July 2010

AbstractNumerical solutions of the flow equation for the drying of porous media have been obtained assuming an exponential relationship between diffusivity and water content. Solutions are presented for both semi‐infinite and finite media for isothermal conditions, when gravity is absent or negligible. The rate of drying of laboratory soil columns is in good agreement with the numerical solutions. The rate of drying is controlled largely by the boundary conditions and physical characteristics of the soil that determine the rate of movement of water in the soil in the liquid phase.
Allophane Determination in Ando Soils By Cation‐Exchange Capacity Delta Value
Authors: Aomine Shigenori , Jackson M. L. 
Published: July 2010

AbstractOne sample of H2O2‐treated, iron oxide‐extracted soil is treated with 2% Na2CO3 solution for 60 minutes and another with NaOAc of pH 3.5 for 15 minutes, at boiling. Both samples are washed with neutral NaOAc and the cation‐exchange capacity is determined with Ca replaced with NaOAc. The difference obtained between the two samples is referred to as the “cation‐exchange capacity delta value,” and averaged 100 me. per 100 g. for allophane from Ando soils of Japan developed on rapidly weathered volcanic ash and in some allophanes of Ross and Kerr. For example, the allophane content of fine clay of an Ando soil containing predominantly halloysite determined by delta value was 23.8% compared to 21.4% by water contents of constituent minerals.
Decomposition and Aggregating Effect of Fungus Cell Material in Soil
Authors: Martin J. P. , Ervin J. O. , Shepherd R. A. 
Published: July 2010

AbstractA study was made to compare the rate of decomposition and aggregating effect in soil of a variety of plant residues and fungus cell materials, and to study the influence of different fungus species and fungus cell constituents on soil aggregation. Based on CO2 evolution during incubation in soil, plant and fungus residues decomposed in the following order: light‐colored fungi > dark‐colored fungi = benzene‐alcohol‐extracted light‐colored fungi > plant residues > benzene‐alcohol‐extracted dark‐colored fungi. In all groups specific decomposition rates varied greatly. The soil‐aggregating influence of all five groups varied over approximately the same range. The ether‐soluble components of the fungus mycelium exerted a much greater binding action than the plant or whole fungus residues. In pure culture Epicoccum purpurascens was outstanding in its aggregating influence. Other effective species included Aspergillus versicolor, Diplodina sp., Pyrenochaeta sp., Stachybotrys atra, Stemphylium consortiale, and Volutella sp. A metabolic substance synthesized by E. purpurascens, crude polysaccharides from Phaeoscopulariopsis sp. and Acrotheca sp., and the alcohol‐soluble constituents of S. atra exerted a marked binding action on the soil. The E. purpurascens product was very resistant to decomposition. Methyl alcohol‐soluble material from Pullularia pullulans decomposed readily but exerted little binding action.
Analyses of Several Brazilian Soils in Relation to Plant Responses to Sulfur
Authors: McClung A. C. , de Freitas L. M. M. , Lott W. L. 
Published: July 2010

AbstractGreenhouse studies indicated many soils of the central plateau of Brazil to have a poor S supply. The most acute deficiency was found on soil from an upland savanna, but surface soils (0 to 20 cm. A0 excluded) from virgin forests also responded. The B horizon of cultivated soils responded less frequently than that of the virgin soils, suggesting some downward movement of S under cropping. Such movement was also indicated by higher levels of NH4OAc‐extractable S. Sulfur extracted in this way correlated well with growth responses of millet grown in pot culture. In most soils, the addition of 20 pounds S as CaSO4 per 2 million pounds of soil resulted in maximum dry matter production under the intensive cropping existing in these experiments. It is postulated that responses to S in this region will not be common unless N and P levels are improved. If these elements are plentifully supplied, however, and cropping is intensive, S deficiencies may occur on many soils.
Evapotranspiration and Yield of Corn as Influenced by Moisture Level, Nitrogen Fertilization, and Plant Density
Authors: Carlson C. W. , Alessi J. , Mickelson R. H. 
Published: July 2010

AbstractYields and evapotranspiration rates by corn grown in Gardena loam at two levels of soil moisture, two plant densities, and several rates of N fertilization were studied for two growing seasons.Neither N fertilizer nor plant density influenced yields in the nonirrigated treatment, but in the irrigated treatment corn yields in both plant densities increased when N fertilizer was applied. Measurements made on the number of kernels per square foot, and individual kernel weights showed that grain yields were most influenced by the number of kernels produced per unit area. Neither N fertilizer nor plant density appreciably affected the evapotranspiration rate. Evapotranspiration was considerably greater for the irrigation plots than for the nonirrigation plots. Rates of evapotranspiration were higher in 1957 than in 1956. The pounds of dry matter produced per inch of water used in evapotranspiration (water‐use efficiency) was appreciably increased by using a high plant density and N fertilizer. This effect was much less marked in the nonirrigated treatments than in the irrigated. The amount of dry matter produced per inch of water used was greater on the nonirrigated treatment than on the irrigated treatment, except at the high N rate in the high plant density. It is apparent that if maximum efficiency of moisture use is to be realized, adequate fertilizer and plant densities are required.
A Rainfall Erosion Index for a Universal Soil‐Loss Equation
Authors: Wischmeier Walter H. 
Published: July 2010

AbstractExtensive regression analyses of basic soil‐loss data were designed to determine the best indicator of the capacity of a storm to erode soil. The rainstorm characteristic found to be outstanding as such an indicator is the variable whose value is the product of the rainfall energy and maximum 30‐minute intensity of the storm (designated as EI). This variable explained from 72 to 97% of the variation in individual‐storm erosion from tilled continuous fallow on 6 soils. Seasonal rainfall erosion index values computed by adding the EI values of storms > 0.5 inch explained as high as 94% of the yearly deviation in total soil loss from fallow during the summer season. Tested against data from plots in continuous row crop for 10 or more years at each of four widely separated locations, the summed EI values explained from 72 to 85% of the yearly variation in soil loss within corresponding cover periods. Expected annual values of the index and seasonal distribution of the erosion potential may be readily computed from local rainfall records. This has been done for 60 locations in the 31 Eastern States.About 8,000 plot‐years of basic erosion data are being analyzed to evaluate factors for a universal soil‐loss equation for which the erosion potential of expected local rainfall serves as the base. Tests show that estimates of average erosion losses computed in this manner are sufficiently accurate to serve as sound bases for conservation farm planning.
The Influence of Alfalfa, Bromegrass, and Corn on Soil Aggregation and Crop Yield
Authors: Barber Stanley A. 
Published: July 2010

AbstractThe influence of alfalfa, bromegrass and a mixture of the two on soil structure was investigated in an experiment in which each crop was grown for 1, 2, 3, and 4 years. Continuous corn was also grown. All plots were heavily fertilized in an attempt to avoid yield differences due to nutrient factors. Soil samples for physical analyses were taken in each of two years. Percentages of water‐stable aggregates were determined. The aggregation index obtained by this procedure was higher after bromegrass than after alfalfa and higher after alfalfa than after corn. The alfalfa‐bromegrass mixture gave a value intermediate between alfalfa and bromegrass. The aggregation index increased in a linear fashion with each additional year of bromegrass or alfalfa up to the 4 years used in the experiment. The aggregation index was not affected by the number of years of corn. Preliminary data indicate that corn yields were affected little by the aggregation index.
Ion Movement in Wyoming Bentonite During Electroosmosis
Authors: Jacobs Hyde S. , Mortland M. M. 
Published: July 2010

AbstractThe comparative rates of removal of the ions from Wyoming bentonite‐quartz sand systems during electroosmosis were as follows: Na+ > K+ > Mg++ > Ca++. The differential movement of ions tends to separate the cations as they move through the media. The percentage of an ion removed by a given amount of electricity was increased by the addition of a complementary ion.The rate of Na+ and K+ removal was proportional to the amount of these ions remaining in the system and decreased steadily as electroosmosis proceeded. The rate of Ca++ removal tended to remain more or less constant until the Ca++ concentration in the cell had been reduced to about 0.5 symmetry.In the early stages of electroosmosis the transference numbers of Na+ and K+ in systems containing no free salt were very near unity. Under similar circumstances the transference number for Ca++ was greater than in some salt solutions but did not approach unity.The amount of water flow per milliequivalent of cation removed was greatest for Ca++, intermediate for K+, and least for Na+.