bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soil Strength and Aeration Effects on Root Elongation
Authors: Voorhees W. B. , Farrell D. A. , Larson W. E. 
Published: July 2010

AbstractPrimary root elongation rates of pea seedlings (Pisum sativa L. ‘Alaska’) and soil resistance to penetration of a probe were measured in remolded cores of sandy loam and clay soils over a soil water suction range of 0.1–1.0 bar. Physical soil resistance was varied by varying soil bulk density and water content. Primary root elongation was more closely correlated with soil resistance to a 10° probe than a 60° probe. It was also more closely correlated with soil resistance normal to the probe, which does not include soil‐metal friction, than with total point resistance which does include the friction component. While soil‐metal friction may not be equivalent to soil‐root friction, this correlation suggests that friction between root cap and soil may be negligible.About 73% of the variation in primary root elongation was accounted for using normal point resistance to a 10° probe and including the effects of air‐filled pores in the bulk soil. Primary root elongation was most sensitive to air‐filled porosity at low levels of soil physical resistance.Root length density increased as soil resistance increased due to increased production of first‐order laterals and decreased rooting depth.
Effect of Thinning on the Foliage and Forest Floor Properties of Ponderosa Pine Stands
Authors: Wollum A. G. , Schubert Gilbert H. 
Published: July 2010

AbstractThe longest and heaviest needle fascicles were associated with greater thinning intensities of ponderosa pine (Pinus ponderosa Laws.) stands 8 years after treatment. The foliar nutrient concentrations did not change significantly between the various thinning regimes. In addition the total forest floor in thinned and unthinned ponderosa pine stands ranged from 17.7 to 34.4 metric tons/ha. On a dry weight basis the F2 horizon constituted 74–88% of the total forest floor. However, nutrient concentrations increased from the foliage to the L to the F1 to the F2 which had the greatest concentrations of nutrients but were not affected by thinning intensity. The greater concentrations in the F2 were probably indicative of the more advanced degree of decomposition. Total nutrients in the forest floor were inversely proportional to the degree of thinning. In the stands at the growing stock level of 6.9 and 48.2 m2/ha (unthinned) total nitrogen was 213 and 301 kg N/ha, respectively. Other nutrient values were 17 and 27 kg P/ha, 18 and 32 kg S/ha, 56 and 75 kg K/ha, 119 and 154 kg Ca/ha, 75 and 126 kg Mg/ha, 26 and 34 kg Zn/ha, and 88 and 156 kg Mn/ha in the stands with growing stock levels of 6.9 and 48.2 m2/ha, respectively.
The Use of Urea and Sulfur‐Coated Urea for Corn Production in a Tropical Soil
Authors: Dalal R. C. 
Published: July 2010

AbstractPlacement of applied N at surface and at the 5‐cm depth at the rates of 50, 100, and 200 kg/ha of urea and sulfur‐coated urea (SCU) were used to measure changes in grain yield and N uptake by corn (Zea mays L.) grown during the wet season in Trinidad. SCU performed better than urea. Surface applied SCU was more efficient than when placed at 5 cm depth. Urea placed at 5 cm depth was more efficient in corn production than when applied on the surface.
The Influence of pH on the Adsorption of Phosphate by Soils from the Guinea and Sudan Savannah Zones of Nigeria
Authors: Mokwunye Uzo 
Published: July 2010

AbstractAn increase in pH of soils from the savannah zones of Nigeria to which varying quantities of phosphate were added increased the phosphate adsorbed by the soils. It is suggested that high pH increased the activity of hydroxy‐aluminum. Phosphate was adsorbed on the surface of the hydroxy‐aluminum species when the hydroxy‐aluminum‐phosphate attraction was strong enough to displace surface OH‐ ions.As a result of increased P adsorption, the phosphate buffer capacity as well as the amount of phosphate required to attain a desired level of P in equilibrium solution increased. It is concluded that a successful liming program in the savannah soils must take into consideration increased phosphate fertilizer rates necessary for adequate nutrition.
Loess in Ohio in Relation to Several Possible Source Areas: I. Physical and Chemical Properties
Authors: Rutledge E. M. , Holowaychuk N. , Hall G. F. , Wilding L. P. 
Published: July 2010

AbstractThin loess deposits east of the Little Miami, Scioto, and Muskingum rivers in Ohio were investigated (i) to test the hypothesis that these river valleys were source areas for the loess that adjoins them, (ii) to determine if multiple loess strata occurred within any of the loess deposits, and (iii) to approximate, where possible, the geologic age of the loess. The loessial materials were investigated using morphological, chemical, and physical parameters. Particle‐size data were expressed on a fine earth and clay‐free basis. The fine earth basis was useful in detecting pedogenic development. Clay‐free data were used in establishing changes in parent material with depth and, perhaps more importantly, in development of relations between particle‐size and distance from proposed source areas.Scioto and Muskingum river valleys were the chief source areas for the loess in the adjoining study areas, but the Little Miami Valley was not the primary source of the loess in the study area adjacent to it. Multiple loess deposits were identified only adjacent to the Muskingum River. All upper loess units were considered to be of comparable age; Late Wisconsin (Peoria Loess). The middle loess adjacent to the Muskingum River was considered to be Farmdale (Roxanna Silt) and the lower loess at the same site was considered to be Loveland loess (Loveland Silt) and contained a well‐developed Sangamon paleosol.
Translocation of Iron In Acid Sulfate Soils: II. Production and Diffusion of Dissolved Ferrous Iron
Authors: Harmsen K. , van Breemen N. 
Published: July 2010

AbstractField and laboratory data on one acid sulfate soil are used to compute the concentration of dissolved Fe2+ with depth and time by means of a mathematical model that considers simultaneous production and diffusion of aqueous Fe2+ during submergence.Calculated ferrous iron concentrations compare well with concentrations measured in the course of 175 days at six depths down to 150 cm below the soil surface. Discrepancies between the model and field data for one depth may be attributed to mass flow induced by sampling of the soil solution.The results are useful in interpreting the processes involved in the typical ferric oxide and jarosite accumulations observed in the B horizon of most acid sulfate soils in Thailand. During flooding small but significant amounts of iron diffuse towards the B horizon. The calculated fluxes of iron are too small to explain the observed ferric iron accumulation by diffusion of Fe2+ during the flooding period only. Diffusion and evaporative mass flow of Fe2+ liberated by pyrite oxidation in the C horizon during the dry season appear to be more important.
Bulk Density Sampler for Deep Soil Profiles
Authors: Holtzclaw K. M. , Rible J. M. , Pratt P. F. 
Published: July 2010

AbstractA bulk density sampler, adapted from a conventional commercial type, was constructed and used to obtain soil samples at more than 50 sampling sites from depths to 30 m. This sampler increased the speed with which samples were taken because it was readily added to or detached from the drilling unit between sequences of drilling. Evaluations showed that the sampler obtained bulk density values quite comparable with those found with an undisturbed soil core method.
Determination of Soil‐Water Diffusivity for Anisotropic Stratified Soils
Authors: Sawhney B. L. , Parlange J.‐Y. , Turner N. C. 
Published: July 2010

AbstractThe unsaturated soil‐water diffusivity of an anisotropic soil can be described by a second‐order tensor. In the particular case of a stratified soil, the diffusivity tensor is defined by the two values of the diffusivity in the principal directions, one normal and one parallel to the soil layer. The standard method of Bruce and Klute then requires the use of two soil columns, one for each direction, to define the diffusivity tensor. The present method makes use of a two‐dimensional similarity solution first derived for an isotropic medium and extended here to a stratified soil. It is then possible to obtain the diffusivity tensor of the stratified soil from one experiment only. As an illustration of the method, the diffusivity tensor of a mica layer is measured and the result is used to analyze infiltration from a finite trench.
Influence of Long Term Tillage, Crop Rotation, and Soil Type Combinations on Corn Yield
Authors: Van Doren D. M. , Triplett G. B. , Henry J. E. 
Published: July 2010

AbstractStudies to compare the relative ability of a wide range of tillage and crop rotation combinations (3×3 factorial) to sustain corn (Zea mays L.) production on several soils typical of Ohio were initiated in 1962. Soils were a well‐drained Wooster silt loam (Typic Fragiudalf), an imperfectly drained Crosby silt loam (Aeric Ochraqualf), a very poorly drained Hoytville silty clay loam (Mollic Ochraqualf), and a very poorly drained Toledo clay (Mollic Haplaquept). Tillage treatments were no‐tillage; plow and then plant; and plow, disk, and plant. Rotations were continuous corn, corn‐soybeans, (Glycine max L.) (2 year), and corn‐oats (Avena sativa L.)‐meadow (3 year) with each crop appearing each year in each rotation. Results are reported only for plots having equal plant density within a site‐year combination, and adequate weed control.Corn yields were remarkably insensitive to tillage. The two plowed treatments had equal yield for virtually all years at each site within the same rotation. The no‐tillage treatment averaged 975 kg/ha or 13% lower yield than the average of plowed treatments on the Mollic Ochraqualf soil for 10 years of continuous corn, but had the same yield as the plowed treatments for the other two rotations. The no‐tillage treatment averaged 750 kg/ha or 10% greater yield than the average of plowed treatments on the Typic Fragiudalf soil for 11 years of continuous corn or corn‐soybeans rotation. Otherwise tillage treatments generally produced the same corn yield within site‐rotation combinations.
The Theoretical Interpretation of Field Observations of Soil Swelling Through a Material Coordinate Transformation
Authors: Sposito Garrison , Giraldez Juan V. , Reginato Robert J. 
Published: July 2010

AbstractThe nature of material coordinate transformations and their importance to the theoretical interpretation of time‐dependent data taken on swelling soil‐water‐air systems is discussed. A material coordinate transformation that is based on a special case of a general relation derived by Raats and Klute, but that has not yet been applied to swelling soil, is proposed as a useful expression with which to describe one‐dimensional soil water processes in the field. This transformation requires only the measurement of bulk density in time sequence from a set of one or more fixed points and, therefore, should be especially valuable when used in conjunction with dual energy gamma‐ray measurements of soil profile properties. An illustrative application of the proposed transformation is made to interpret dual energy gamma‐ray data on the swelling of Avondale clay loam.
Potassium Status of Selected Paleudults in the Lower Coastal Plain
Authors: Yuan T. L. , Zelazny L. W. , Ratanaprasatporn A. 
Published: July 2010

AbstractAn attempt was made to explain the lack of crop response to K fertilization for corn (Zea mays L.), soybean (Glycine max L.), and small grain in some Ultisols in the Lower Coastal Plain. Profile samples of a Rhodic Paleudult (Red Bay fsl), a Plinthic Paleudult (Dothan fsl), and Psammentic Paleudult (Eustis lfs) were analyzed for exchangeable K, nonexchangeable K which could be released, and total soil K. Although the first two forms of K were relatively low, a K reserve of about 1,500–2,800 kg/ha was found in each 15‐cm thickness of soil sampled throughout these soil profiles. Potassium may be released from this reserve as indicated by the hot 1N HNO3 extraction which produced an amount of K equivalent to 96 kg or better/ha for each 15‐cm soil depth. Chemical studies showed that this K was not associated with noncrystalline hydrous oxides, silicates, or phosphates. No K‐bearing minerals were evident in X‐ray diffractograms of clay fractions except after removal of noncrystalline material, but peaks for K‐feldspars were observed in silt fractions. Sodium pyrosulfate fusion method suggested that slightly < 50% of the K reserve occurred in the K‐feldspar form and most of the rest was probably in micaceous mineral forms.
Soil Reflectance Measurement Using a Photographic Method
Authors: Gold A. , Asher J. Ben 
Published: July 2010

AbstractThe albedo of two soils, Avondale clay loam and Yuma sand dunes, was determined using a panchromatic film in a hand‐held 35‐mm camera. Samples with different volumetric moisture content, from air dry to saturation, were compared to calibrated reference surfaces of evenly distributed tones of gray. For the limited spectral sensitivity of the detector (panchromatic film), a correction factor K′ was derived graphically from known spectral reflectance of a different soil. The albedo is given by the product of the correction factor and the fraction of the reflected radiation that contributes to the detector signal. The results obtained by the photographic method were in good agreement with results obtained by conventional radiometric methods for Yuma sand dunes, but larger differences were found between radiometry and photography for Avondale clay loam.
Exchange and Hydration Properties of Cu2+ on Mixed‐ion Na+‐Cu2+ Smectites
Authors: McBride Murray B. 
Published: July 2010

AbstractThe exchange of Na+‐montmorillonite with Cu2+ was studied using X‐ray diffraction, electron spin resonance (esr) and a specific Cu2+ electrode in order to investigate the hydration and exchange properties of mixed Cu2+‐Na+ clay systems. With < 30% of the exchange sites occupied by Cu2+, the clays behave much as pure Na+‐montmorillonite and swell freely in water. Larger exchange levels of Cu2+ produce more ordered interlayers at low relative humidities. At high relative humidities, this ordered structure is reduced and a solution‐like environment is produced as the aluminosilicate sheets further separate. Exchange isotherms demonstrate a large preference for Cu2+ over Na+ at low Cu2+ exchange levels but preference for Na+ at high Cu2+ levels. In contrast, Cu2+‐Mg2+ exchange does not show this effect, indicating that certain exchange sites on the silicate structure preferentially adsorb divalent cations. Thus, Cu2+ ions are effectively removed from solution by Na+‐montmorillonite, but are not adsorbed in preference to other divalent cations.
Urea and Ammonium Sulfate Fertilization of Potted Slash Pine under Two Soil Moisture Regimes
Authors: Sarigumba T. I. , Pritchett W. L. , Smith W. H. 
Published: July 2010

AbstractTwo‐year‐old slash pine seedlings grown in lysimeter pots, filled with a Spodosol, received three levels of N from two sources, (NH2)2CO and (NH4)2SO4, under two soil moisture regimes. Tree growth was greater when soil matric suction limit was set at 170 cm than at 500 cm of water. Slash pine growth response was greater to (NH2)2CO than (NH4)2SO4. Urea fertilization resulted in greater nutrient uptake by the seedlings during a 9 month period. On the other hand, (NH4)2SO4 favored higher nutrient leaching losses. In general, where growth response was best, nutrient uptake was greatest and leaching losses were least.
A Background Temperature Correction for Thermal Conductivity Probes
Authors: Jury W. A. , Bellantuoni B. 
Published: July 2010

AbstractA procedure is outlined for correcting the thermocouple reading of a thermal conductivity probe for changes in temperature caused by external warming or cooling of the soil during the period of measurement. A background temperature measurement is made for several minutes with the probe heater turned off, and the estimated temperature change due to the surroundings is then subtracted from the change caused by the probe heater. A laboratory experiment using a buried probe exposed to surface heating demonstrated a substantial reduction in the errors for the values of conductivity measured for a soil of known thermal properties when the correction was used.
Adsorption of Dodecylbenzene Sulfonate on Na+‐montmorillonite: Effect of Salt Impurities
Authors: Clementz David M. , Robbins John L. 
Published: July 2010

AbstractThe adsorption of purified dodecylbenzene sulfonate (ABS) on Na+‐montmorillonite follows the Langmuir isotherm, reaching a maximum amount adsorbed which corresponds to the anion exchange capacity of the clay. When a commercial grade ABS (containing 60% Na2SO4) is used, the adsorption process is more complex and occurs in two distinct steps. In dilute solutions, the salt impurity has a minor effect on adsorption and the result is essentially the same as that obtained for the purified surfactant. However, as the salt concentration is increased to a given value, enhanced adsorption due to hemimicelle formation occurs.
Stimulation of Plant Growth by Humic Substances
Authors: Lee Yong Seok , Bartlett Richmond J. 
Published: July 2010

AbstractHumic substances prepared by different techniques of extraction and from different sources of organic materials were tested for their effects on growth of corn seedlings and algae. Stimulating effects were confirmed with optimum concentrations about 5 ppm C as Na‐humate for corn and 60 ppm for algae. With corn, the increase was 30 to 50% in nutrient solution or low organic matter soil; with algae, about 100%. Variation of effects among humic acids derived from different organic materials was not great.The concentrations of elements in corn seedlings did not show any correlation with yield or humic acid level except for P and Fe. Phosphorus concentration was increased with increasing levels of humic acid regardless of the yield response. Higher Fe concentration in the plant tops and lower in roots was observed in the treatments with humic acid.The application of humic acid to a soil low in organic matter or to nutrient solution gave the greatest growth response. Application to a high organic matter soil gave little growth response, or even a slightly negative response, indicating that the natural soil, without extraction, supplied optimum amount of humic substances to the plants. It is suggested that a test be developed to predict whether a given soil can furnish an optimum level of humic substances.Different humic substances showed different degrees of stimulation of algal growth, with the most stimulation from a mixture of humic and fulvic acids. Humic substances in paddy soils may affect the growth of beneficial algae and of the rice (Oryza sativa L.) itself. As pollutants, humic substances may stimulate undesirable algal growth in bodies of water.
A Centrifugal Filtration Method for Isolating Rhizocylinder Solution
Authors: Soon Y. K. , Miller M. H. 
Published: July 2010

AbstractTo measure the phosphate concentration in the soil solution adjacent to plant roots, a method of isolating the rhizocylinder solution was developed. A major factor in the choice of a method is that it should be rapid and should not alter the solution salt concentration during isolation. The centrifugal filtration method satisfies both conditions for bulk soil samples; it was subsequently applied to the rhizocylinder (roots plus adhering soil). Root sap leaking from corn (Zea mays. L) roots during centrifugation introduced a significant error in the rhizocylinder solution phosphate concentration for a sandy loam with a low solution phosphorus concentration. For two medium‐textured soils with a higher solution P concentration, the error was negligible. The method is considered suitable for the latter soils.
Contribution of Lateral Soil Water Movement above a Fragipan to Streamflow
Authors: Palkovics W. E. , Petersen G. W. 
Published: July 2010

AbstractA water balance approach to the hydrologic budget on a small mountainous watershed in central Pennsylvania was used to determine if lateral water flow perched above a soil fragipan could be quantitatively related to streamflow. Perched water table fluctuations were measured using a grid of 60 observation wells and streamflow was recorded using a weir. This site was monitored in mid‐November when evapotranspiration was at a minimum and when no precipitation was recorded. Soil water yield due to perched water table decline was calculated, hydraulc conductivity and the rate of water movement through the soil computed, and the zone of water contribution to streamflow determined. Results indicated water yield from the soil aquifer explained streamflow. Saturated water flow was shown to be the main mechanism of water movement, although unsaturated flow may have been significant for short distances under low tensions. The major zone of soil water contribution to streamflow was the more poorly drained soils adjacent to the stream. Unsaturated soils on the upper mountain flanks had little affect upon streamflow because of their low gradient and their large distance from the stream.
Soilscape Analysis of Slightly Contrasting Terrains in Southeastern Wisconsin
Authors: Pavlik Hannah F. , Hole Francis D. 
Published: July 2010

AbstractFabric analysis using detailed soil maps and modal soil descriptions was made of two contrasting ground moraine terrains, with and without drumlins, respectively, in southeastern Wisconsin. Heterogeneity within soil bodies was acknowledged, but the landscapes were contrasted primarily on their distribution of soil mapping units. Comparison and reclassification was achieved by multivariate discriminant analysis procedures using 29 variables derived from consideration of 18 soil body characteristics. Results of the study also included population density of soil bodies; range in relief; relative dominances of soil drainage classes, of soils formed in alluvium and colluvium, of loess thickness classes among upland soils, and of soil series. These were characterized independently of the computer analysis.
Soil Deterioration on Campsites: Northern Forest Types
Authors: Legg Michael H. , Schneider Gary 
Published: July 2010

AbstractCamping use and soil deterioration were monitored on 12 campsites in northern Michigan during their third and fourth camping seasons. Sites were on previously undisturbed Gogebic fine sandy loam (Typic Fragiorthod), under mature northern forest cover. Percentage of litter cover, soil macropore space and depth to A2 horizon decreased, and soil bulk density increased with time during both use seasons. Deterioration increased greatly on all campsites with intensity of use. Except for depth to A2 horizon, measured parameters recovered partially over winter, but recovery was less than deterioration during the previous summer.
Determination of Soil Aluminum in Barium Chloride Extracts by Aluminon Method
Authors: Khalid R. A. 
Published: July 2010

AbstractBarium chloride solution used to extract soil Al was found to react with an aluminon reagent to form aluminon lake as does Al and enhance color intensity. It is suggested that in soil extracts where aliquots required for Al determination are < 10 ml, additional 1N BaCl2 should be added to give a constant total quantity of 10 ml BaCl2 in all extracts. In soil extracts with low Al concentrations, where aliquots larger than 10 ml are required for analysis using the aluminon method, no corrections for BaCl2 interference are necessary.