bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Alternating Versus Constant Soil Temperatures on Maize Seedling Growth
Authors: Walker John M. 
Published: July 2010

AbstractThe responses of maize seedlings (Zea mays, L.), which were grown with soil temperatures alternating ± 3C about 20, 23, and 26C means and also at equivalent constant soil temperatures, were compared. Soil temperatures were alternated about the means diurnally in synchronization with 12‐hour light and dark periods. Both the alternating and constant soil temperature treatments were applied when seedlings were 7 days old and were maintained for 16 days in a uniform aerial environment (25C air temperature).Alternating soil temperatures about 23 and 26C means yielded more growth than was obtained at the equivalent constant soil temperature. These alternating soil temperature response data could be explained by relating the light, dark, and mean soil temperatures to the optimum constant soil temperatures for growth (leaf length growth was optimum at 20 to 23C, dry weight growth at 23C, and stem growth at 26C). Apparently, soil temperature most strongly influences growth during the light period (daytime) when a plant is photosynthesizing.
Separation of Adsorbed Cation Species as Water Flows Through Clays
Authors: Kemper W. D. , Sills I. D. , Aylmore L. A. G. 
Published: July 2010

AbstractTheory predicts that adsorbed divalent cations move upstream and monovalent cations move downstream in a mixed ion system, when solutions of low concentration are forced through this clay. Data from small size mica support this prediction.
Response of Alfalfa to Boron in Flyash
Authors: Mulford F. R. , Martens D. C. 
Published: July 2010

AbstractThe availability of B in flyash obtained from three coalburning power plants was evaluated by greenhouse and laboratory procedures. The samples of flyash contained 319, 415, and 618 ppm B and neutralized 0.12, 0.58, and 3.05 meq H3O+/g, respectively. Boron in the samples of flyash was readily available to alfalfa (Medicago sativa L). grown on Tatum silt loam. Yield and B uptake data indicated approximately equal availability of B in flyash, 1N HCl extracts of flyash, and Na2B4O7 · 10H2O. Application of high rates of the flyash sample having the highest neutralizing power decreased yield of alfalfa. The decrease in yield was attributed to Zn deficiency of alfalfa plants induced by the increase in soil pH resulting from application of the by‐product.
Field Measurement of Unsaturated Hydraulic Conductivity by Infiltration through Artificial Crusts
Authors: Bouma J. , Hillel D. I. , Hole F. D. , Amerman C. R. 
Published: July 2010

AbstractField trials were made to test the applicability of a recently proposed method for measuring the unsaturated hydraulic conductivity (K) of crust‐capped soil materials in a one‐dimensional flow system, where the matric suction gradient is zero. K‐values were determined from infiltration rates into crust‐capped soil columns carved out in situ 30 cm in height. Matric suctions were measured with tensiometers. Examples are given for four Wisconsin soil horizons.
Soil Water Evaporation: Reduction by Simulated Tillage
Authors: Willis W. O. , Bond J. J. 
Published: July 2010

AbstractSoil water loss with time as affected by simulated tillage to depths of 2.5 and 7.5 cm was measured from soil columns in a constant temperature room. The 60‐cm soil columns were initially wetted from the top to about 33% by volume and then covered for 2 days to prevent evaporation. Tilling was done at 1, 4, 7, and 18 days after the columns were uncovered. Tillage effectively terminated first stage drying, and evaporative losses were reduced by tilling. The highest reduction of evaporation was associated with earliest tilling, which showed over 50% reduction in evaporative loss for more than 22 days after tilling. The reduction in water loss was reflected in higher soil water content throughout the column length below the tilled layer. Evaporation reduction was only slightly better with 7.5‐cm than with 2.5‐cm tillage.
Field Measurement of Soil‐Water Content by Gamma‐Ray Transmission Compensated for Temperature Fluctuations
Authors: Reginato Robert J. , Jackson Ray D. 
Published: July 2010

AbstractSoil‐water content under natural field conditions was measured with a gamma‐ray transmission technique that compensated for temperature changes. A spectrum stabilizer was needed for the nuclear counting equipment, and a knowledge of the relationship between peak count‐rate and the temperature of the gamma‐ray detector probe was required. Equipment and procedures to make field measurements of water content in 1‐cm‐thick soil layers are described. When the detector probe temperature varied 23C and gravimetric water content ranged from 0.021 to 0.186 gg‐1 over a measurement period, the average deviation of measured versus calculated values of water content was 0.009 gg‐1.
Differential Sr‐Ca Bonding on Soil as Influenced by Bonding Site
Authors: Elgawhary S. M. , Barber S. A. 
Published: July 2010

AbstractThe Sr‐Ca selectivity coefficient, kSr/Ca, was used to interpret the differential Sr‐Ca bonding of cation exchange sites in two soils. A dominant complementary cation, K, was used to place the Sr and Ca on sites which favored Sr and Ca over K. As the equivalent fraction of Sr plus Ca in the equilibrium solution was reduced, kSr/Ca decreased, indicating that organic exchange sites were the first to be filled. When the complementary ion was Mg or Ba, kSr/Ca was much larger, indicating that these complementary ions competed more nearly equally with Sr and Ca for all exchange sites. There was a relationship between the log of the equivalent fraction of Sr plus Ca and kSr/Ca that was linear over segments of the range of equivalent fraction used.Chromatographic separation of Sr and Ca on a Sidell soil reflected the kSr/Ca of this soil at low Sr plus Ca saturations. Little Sr and Ca separation occurred with the Edwards muck apparently because of the over‐shadowing of the readily exchangeable cations by Sr and Ca adsorbed in very slowly exchangeable positions resulting in little movement of these ions.
Composition and Weathering of Loess Mantled Wisconsin‐ and Illinoian‐age Terraces in Central Ohio
Authors: Khangarot A. S. , Wilding L. P. , Hall G. F. 
Published: July 2010

AbstractElemental and mineralogical evidence indicate that both loess and outwash deposits on relatively high Illinoian‐age terraces are more intensively weathered than comparable units of lower level Wisconsin‐age terraces. The Illinoian site, particularly in the outwash paleosol, has lower weight percentages of heavy minerals; lower hornblende contents; lower elemental Fe, K, and Ca contents; and more pronounced pedogenic transformation of micas to partially or fully expandable 14Å components. Subtle weathering trends of elemental Ca, even in the Illinoian paleosol, are attributed to its occurrence in more resistant plagioclase‐feldspars. The 50‐20µ light mineral fraction (sp. gr. < 2.86) in both loess and outwash units contains appreciably higher quantities of Ti, Zr, and Fe than was originally anticipated. From 50–70% of the Ti, 20–45% of the Zr, and 85–90% of the total Fe occurs in light minerals. Essentially all of the K and 70–90% of the Ca also occurs in this isolate. Loci of Fe, Ti, and Zr in light minerals have not been established but are postulated to be either micro occlusions of primary minerals in host framework silicates or proxy for other metallic cations in these structures.
Use of Soil Cores in Determining Bulk Density
Authors: Goddard Tyrone M. , Runge E. C. A. , Walker W. M. 
Published: July 2010

AbstractThe bulk density of soil samples obtained with a hydraulic soil coring machine, for both core segments and clods, was compared to the bulk density of soil samples obtained with a Uhland sampler and natural clods taken from a soil pit. Subsurface, upper B, and lower B horizon samples were compared. Clods gave bulk density values that were significantly higher than cores in the upper solum, where small structural units occur; however, in the lower solum, where soil structural units are large or massive, variation between clods and cores was not statistically significant. There was no significant difference in bulk density due to the method of obtaining clods or cores.
Nitrate Adsorption: II. In Competition with Chloride, Sulfate, and Phosphate
Authors: Kinjo T. , Pratt P. F. 
Published: July 2010

AbstractIn anion‐exchange equilibria studies on two Andepts and one Oxisol, Cl‐ showed a slight preference over NO3‐, and SO42‐ and H2PO4‐ were greatly preferred over NO3‐. Negative adsorption of NO3‐ occurred when SO42‐ or H2PO4‐ exceeded certain concentrations. Under limited conditions, increases in Cl‐, SO42‐, or H2PO4‐ adsorption caused proportional decreases in the amounts of NO3‐ adsorbed. On a mmole basis, the decreases in NO3‐ adsorption equaled the increase in adsorption of other anions, except in the case of H2PO4‐, where about 3 to 4 mmoles of H2PO4‐ were adsorbed for a decrease in the adsorption of 1 mmole of NO3‐, suggesting that H2PO4‐ reacts with more sites of the same type and/or with types not available for NO3‐ adsorption.
Complex Reactions of Zinc With Organic Matter Extracted From Sewage Sludge
Authors: Tan K. H. , King L. D. , Morris H. D. 
Published: July 2010

AbstractThe organic fraction of sewage sludge, extracted with 0.1 N NaOH and separated into low and high molecular weight fulvic fractions by Sephadex G‐50 gel filtration, was studied for its Zn‐complexing capacity by the ion‐exchange equilibrium method and infrared spectroscopy.The number of moles of fulvic compounds complexed by 1 mole of Zn at pH 5.5 was low in the case of the high molecular weight fraction, but the low molecular weight fraction was complexed in amounts twice that stated for the high molecular weight compounds. By increasing the pH to 7.0 a 10‐fold increase in amounts of low molecular weight fractions complexed by Zn was obtained. The stability constant also increased from 1.8 (pH 5.5) to 6.8 at pH 7.0 for the low molecular weight complex compounds.The organic preparations had infrared characteristics similar to those reported earlier for polysaccharides. A shift in OH band from 3500 to 3200 cm‐1 and a sharp increase in carboxyl stretching vibration at 1650 and 1400 cm‐1, observed in the spectrograms of the Zn‐complexes, indicated the formation of coordinate covalent bonds between OH groups and Zn and electrovalent linkages between COO‐ and Zn, respectively.Estimation of the free energy change (ΔGr) for Zn‐complex reactions suggested at least two possibilities for stable Zn‐complex formation.
Characteristics and Classification of Three Wisconsin Histosols
Authors: Frazier B. E. , Lee G. B. 
Published: July 2010

AbstractOn the basis of morphology, pH, and solubility in Na4P2O7, three Wisconsin histosols were classified as (i) a Fibrist, (ii) a Hemist, and (iii) a Saprist.Fiber content was found to be the single most useful characteristic in the classification of these Histosols, and in quantifying various stages of decomposition and soil formation in histic materials. Fibric material consisted of 70% or more fiber as determined on a gravimetric basis, using a 140 mesh sieve to separate fibrous (> 0.1 mm) from nonfibrous (< 0.1 mm) material. The fiber content of hemic material ranged from 35 to 60%; sapric material contained < 15% fiber. Sodium pyrophosphate extract color (SPEC) is a useful parameter in the characterization and classification of histic materials.Results of other analysis showed that the carbon content of the organic fraction was highest in the Saprist and lowest in the Fibrist. Oxygen and hydrogen contents were, in general, inversely related to fiber content. Total nitrogen appeared to be dependent on botanical composition of parent plants and microbial activity of the soil; the relatively high nitrogen content of certain subsurface layers may be related to illuvial deposition of mobile, nitrogen‐containing substances. Mineral content was likely influenced by additional colluvial or eolian sediments.Good structure was found in both surface and subsurface layers of the Saprist. It is suggested that highly decomposed Saprists possessing good structure in surface and subsoil horizons be placed in a separate great group.
Hydraulic Properties of an Ortstein Horizon
Authors: Lambert J. L. , Hole F. D. 
Published: July 2010

AbstractAn ortstein horizon was encountered in a soil profile identified as a Wallace loamy sand on the glacial outwash plains of central Wisconsin. The horizon was distinguished by its color, strength properties, free iron concentrations, and bulk density. Laboratory and in situ field measurements of capillary conductivity indicated that the horizon was more permeable than the profile above it during wet conditions, and that it became less permeable than adjacent horizons as the soil dried out. Water retention of this ortstein horizon was greater than the rest of the profile by as much as 40%. The greatest differences in hydraulic properties were associated with the layer of maximum bulk density, while the maximum iron concentrations were observed at a slightly lesser depth.
Phosphorus Fixation by Montmorillonite and Vermiculite Clays as Influenced by pH and Soluble Aluminum
Authors: Hall J. K. , Baker D. E. 
Published: July 2010

AbstractPhosphorus fixation in montmorillonite and vermiculite clays, each with a cation exchange capacity of 116 meq/100 g, was studied at various levels of Al, P and pH. Aluminum was added at rates of 0, 22.5, 45 and 90 meq/100 g to the H‐saturated clays. The clays were adjusted and equilibrated to pH levels of 4, 5, 6, and 7 prior to the addition of P at rates of 0, 200, 400, 800 and 1,600 ppm. After 14 days, a standard amount of 32P was added to each sample in order to obtain a measure of labile P by isotopic dilution. X‐ray patterns of the clays were obtained for each sample after drying at 25, 200, 300, and 550C.Montmorillonite fixed increasing amounts of P as the pH increased, while vermiculite fixed less P as the pH increased. The fixed fraction in montmorillonite was characterized by a greater percentage of labile P than that associated with vermiculite. Stable 14 angström basal (001) spacings were detected in vermiculite at 300 C indicating the presence of stable Alpolymers within the interlayer spaces. No evidence of stable interlayer Al polymers was detected in the montmorillonite suspensions. The results help explain why the effect of liming on P availability is not the same for all soils. For soils containing clays that react like the vermiculite of this study, additions of lime prior to adding P will reduce the reactivity of Al through the formation of stable interlayer Al polymers which effectively reduces the specific surface of reactive Al and P adsorption sites. Additions of lime to soils containing clays that react like the montmorillonite of this study would increase P fixation. However, increased fixation by montmorillonite might not be associated with decreased uptake of P by plants since the latter has been shown to increase as the amounts of labile P increases.
Losses of Nitrogen from Some Flooded Soils in Tracer Experiments
Authors: Broadbent F. E. , Tusneem M. E. 
Published: July 2010

AbstractNitrogen losses were measured in laboratory and greenhouse experiments in four flooded soils after addition of 15N‐tagged (NH4)2SO4 or rice straw after various incubation periods. Substantial losses occurred in all cases except where NH4+‐N was rapidly immobilized and/or fixed by clay minerals. The necessity for nitrification as a prelude to N loss was demonstrated by showing that no loss occurred when oxygen was excluded and that where no nitrate was produced, no N2 was evolved. Growing rice plants (Oryza sativa) effectively reduced the magnitude of the nitrogen loss.
Reactions and Availability of Banded Polyphosphate in Field Studies
Authors: Miner Gordon , Kamprath Eugene 
Published: July 2010

AbstractThe concentration of fertilizer P from both superphosphate and polyphosphate decreased rapidly with increasing lateral distance from the band. Aluminum phosphate and lesser amounts of Fe phosphates were the soil reaction products formed with essentially no difference between the two P materials. A higher proportion of the condensed phosphate ions were in the difficultly extractable form as compared with the orthophosphate ions, indicating that the condensed phosphate ions are held more strongly. The apparent hydrolysis of condensed phosphates increased with increasing lateral distance from the center of the band. Hydrolysis was greater in the Lynchburg, a low P‐fixing soil, than in the Georgeville, a high P‐fixing soil.Polyphosphate was as effective as superphosphate in supplying P for plant growth. The residual effectiveness of the polyphosphate was similar to that for superphosphate. Although condensed phosphate ions are held more strongly than orthophosphate by soil materials, there appears to be no difference in their effectiveness as sources of P for plants.
Effect of Soil pH on the Availability of Adsorbed Sulfate
Authors: Elkins D. M. , Ensminger L. E. 
Published: July 2010

AbstractA soil solution displacement method was used to evaluate the effect of CaCO3 on soil retention of sulfate. A decreased amount of sulfate retention was noted with increased rates of CaCO3.By means of a split‐root technique, plants of soybeans (Clycine max (L.) Merrill) and cotton (Gossypium hirsutum L.) were grown in a Dothan subsoil which contained a large amount of adsorbed sulfate, and to which had been added several rates of CaCO3. As CaCO3 rate was increased the uptake of sulfate by five crops of soybeans and one crop of cotton grown successively in the same soil was generally greater. A portion of the adsorbed sulfate in the untreated soil was available, but available sulfate became limiting for the third crop of soybeans and for all successive crops of soybeans and cotton.
Comparison of Different Methods in the Transition Matrix Approach to the Numerical Classification of Soil Profiles
Authors: Norris J. M. 
Published: July 2010

AbstractDale et al. (1970) have proposed a method for the numerical classification of sequences which was used by Norris and Dale (1971) for the classification of soil profiles. In the first stage the horizons from all the profiles are grouped and the profiles redescribed as a sequence of groups. In the second stage the sequences are classified by the program TRANSMAT. This paper examines the effect of using different first stage methods, different numbers of groups at the end of the first stage and methods similar to TRANSMAT in the second stage. Both the first stage method and the number of groups used bear significantly on the results. However, alternative techniques to TRANSMAT can be used with little loss of precision but with greatly increased data storage capacity.
Diffusion of Zinc in Soil: II. The Influence of Soil Bulk Density and its Interaction with Soil Moisture
Authors: Warncke D. D. , Barber S. A. 
Published: July 2010

AbstractEffective Zn diffusion coefficients were determined at four soil bulk densities and three moisture levels in five silt loam soils. The tortuosity of the diffusion path, f1, for each set of soil conditions was estimated from 36Cl diffusion data. In each soil and for each soil moisture level the diffusion path was least tortuous near 1.3 g/cm3. The observed order for the influence of soil bulk density on tortuosity was 1.6 > 1.5 > 1.1 > 1.3 g/cm3. Soil bulk density interacted significantly with soil moisture in affecting the Zn diffusion coefficients. The maximum rate of Zn diffusion did not always occur at a soil bulk density of 1.3 g/cm3 where the diffusion path was least tortuous. At 20 and 30% moisture the Zn diffusion rate reached a maximum near 1.5 g/cm3 indicating that tortuosity was not the only factor influencing the rate of Zn diffusion. As the soil moisture was increased, a reduction in the effect of the interaction of Zn with the soil was greater than the effect of tortuosity in determining the effective rate of Zn diffusion in each soil. When the bulk density was increased from 1.5 to 1.6 g/cm3, an increase in both the degree of interaction and toruosity combined to cause a sharp decrease in the Zn diffusion coefficient.
Phosphorus Diffusion in Soils: II. The Effect on Phosphorus Uptake by Plants
Authors: Mahtab S. K. , Swoboda A. R. , Godfrey C. L. , Thomas G. W. 
Published: July 2010

AbstractPhosphorus uptake by grain sorghum (Sorghum vulgare) was measured at four levels of applied P and three levels of moisture on four related Texas soils. The soils differed mainly in clay content. Phosphorus uptake was found to be a function of clay and water content of the soils and applied P. The total increase in dry matter yield for each addition of P was about the same for each soil except at the lowest moisture level. At the lower moisture levels, response to P additions was not as great on the coarser‐textured soils as on the fine‐textured soils.Phosphorus uptake was related to the diffusion coefficients of P previously determined for the four soils subjected to the same treatments as in this study; the correlation coefficient was 0.788.
The Composition of the Soil Atmosphere Beneath a Beef Cattle Feedlot and a Cropped Field
Authors: Elliott L. F. , McCalla T. M. 
Published: July 2010

AbstractThe soil gases beneath a feedlot and an adjacent cropped field were measured at several time intervals and soil depths for a 1‐year period. The gas samples were obtained in situ with gas diffusion equipment protected by caissons installed in the feedlot and field.During warm periods and when the feedlot was not unusually dry, average concentrations of up to 51.5% CH4 and 35.5% CO2 were detected in the feedlot soil profile atmosphere. Methane and CO2 feedlot values for the year averaged from 8–27.5% and 12.5–23%, respectively. When CH4 and CO2 values were high, O2 concentrations were minimal. High CH4 values were recorded up to 152 cm deep in the feedlot. No H2 was detected beneath the feedlot or the cropped field. Oxygen and CO2 values ranged from 12.5–21% and 0.1–5%, respectively, in the cropped field soil profile. No CH4 was detected.Methane and CO2 concentrations beneath the feedlot were lowest in midwinter and during extended drought periods in early summer; O2 concentrations were highest during these periods. The cropped field soil profile showed the highest CO2 values in the summer when the crop was growing vigorously; O2 values were lowest during this period.
Characterization of Aluminum in Volcanic Ash Soils
Authors: Igue K. , Fuentes R. 
Published: July 2010

AbstractBuffered and unbuffered salt solutions were used to characterize Al in acid volcanic ash soils of Costa Rica. The results presented show that the exchangeable Al in the Andosols studied are relatively low as determined by successive extractions with unbuffered salt solutions. When different soils were compared, exchangeable Al seemed to increase as weathering of the soils increased. Buffered 1N NH4OAc at low pH's releases considerable amounts of nonexchangeable Al. In a well developed Andosol, part of nonexchangeable Al seems to be released from organically complexed forms. In more weathered soils, the inorganic forms of Al seemed to be the main source of nonexchangeable fractions.The method of successive extractions with unbuffered salt solutions appeared to provide a reliable measuremnt of exchangeable and nonexchangeable Al. Both 1N KCl and 1N NH4Cl generally extracted similar amounts of Al from soils, and both methods are very sensitive to detect differences due to lime treatments or organic matter destruction.