bluuebunny/crossref_metadata_2025_split huggingface dataset:
Freeze‐Dried and Critical‐Point‐Dried Clay — A Comparison
Authors: Murray R. S. , Quirk J. P. 
Published: July 2010

AbstractThe results of experiments conducted with an illitic soil, which has been freeze‐dried and critical‐point‐dried, confirm that the freeze‐drying process fails to preserve the structure of the swollen material. The pore structures, associated with clay “domains” (<10 nm), in samples freeze‐dried from a wide range of soil‐moisture potential, are improbably similar to that of an air‐dried sample. In addition, the presence of large pores (about 1 µm), which should have drained at the equilibrium suctions, in the normal swelling range, which the samples experienced prior to freeze‐drying, is inconsistent with the capillary rise equation. Furthermore, soil which has been freeze‐dried from 10 kPa suction swells when placed at 5 MPa suction (p/p0 = 0.96). During mercury intrusion, freeze‐dried samples retain most of their total porosity while critical‐point‐dried samples collapse; this collapse is thought to be consistent with the metastable nature of a dry, but swollen, clay structure.
Extractable Chromium as Related to Soil pH and Applied Chromium
Authors: Grove J. H. , Ellis B. G. 
Published: July 2010

AbstractThe objective of this study was to evaluate the soil chemistry of added Cr(III), Cr(VI), and sludge Cr as affected by initial soil pH. Treatments of 0 and 500 ppm Cr as CrCl3 and CrO3, and sludge Cr at a rate of 1,400 ppm Cr were applied to Rubicon sand (Entic Haplorthod, pH 4.7), Morley clay loam (Typic Hapludalf, pH 6.0), and limed Morley clay loam (pH 7.5). Pots were sampled at 24 hours, 1, 2, 4, 8, and 16 weeks of incubation. Soil samples were extracted in succession with distilled water, 1M NH4Cl, 0.1M CuSO4, 0.3M (NH4)2C2O4, and citrate‐dithionite‐bicarbonate.Chromium(III) addition reduced soil pH while sludge raised soil pH. Chromium(VI) treatment initially lowered soil pH but then raised it above the pH of control soils after a short time period. Water‐soluble Cr(III) decreased with time, though more rapidly as soil pH increased. When added as Cr(VI), water‐soluble Cr also decreased with time but less rapidly as soil pH increased. Exchangeable (1M NH4Cl extractable) and organic‐bound Cr (0.1M CuSO4 extractable) were negligible. Oxalate and dithionite extractions removed large quantities of Cr from all treatments. Water‐soluble Cr compounds appeared to convert to insoluble compounds of Cr(III) in soils. Sludge Cr is probably a colloidal precipitate prior to incorporation.
Serogroup Distribution of Rhizobium Leguminosarum in Peas in the Palouse of Eastern Washington
Authors: Mahler R. L. , Bezdicek D. F. 
Published: July 2010

AbstractThe serogroup distribution of Rhizobium leguminosarum in peas (Pisum sativum L. cv. ‘Alaska’) was determined for a Palouse catena in the summer of 1976. Three major serogroups were found, although the distribution was uneven across the catena. Thirty‐four and thirty‐eight percent of the nodules on the bottomland and north slope, respectively, were of serogroup WA‐01, whereas it comprised only 5 to 12% of the root nodule population on the south slope and ridgetop, respectively. Serogroup WA‐02 distribution of 81 to 89% was dominant for the ridgetop and south slopes. Only on the bottomland and soil did serogroup WA‐03 represent a sizeable portion (12%) of the root nodule population.Nine Palouse catenas were selected as study sites in the summer of 1977 to determine the geographical distribution of the three serogroups of R. leguminosarum. The three serogroups represented > 94% of the root nodules sampled. Chisquare analysis suggested that serogroup distribution was related to temperature, moisture, and slope position on a catena. Microclimate as well as macroclimate were responsible for serogroup distribution in the Palouse. Cooler temperatures and higher soil moisture appeared to favor serogroup WA‐01, as its largest population existed in the northern part of the Palouse, and on north‐slope and bottomland soils. Population of serogroup WA‐02 was maximum under the warmer and drier conditions of the southern and western Palouse as well as on south slopes and ridgetops. No pattern was found for the distribution of serogroup WA‐03.
Soilscape Analysis in Terms of Pedogeomorphic Fabric: An Exploratory Study
Authors: Habermann Gail M. , Hole Francis D. 
Published: July 2010

AbstractTen representative published soil photo‐map sheets from Hawaii, Florida, Wisconsin, and selected intervening states were subjected to exploratory analysis for the characterization of soilscapes in terms of pedogeomorphic fabric. Data on size distribution of soil bodies were displayed on a soilscape “textural triangle” in a manner to indicate the degree to which a given soilscape was dominated by unusually large soil bodies. A relationship was indicated between natural drainage condition of soilscapes and number of soil series per km2.
Sources and Properties of Loess Deposits on Crowley's Ridge in Arkansas
Authors: West L. T. , Rutledge E. M. , Barber D. M. 
Published: July 2010

AbstractCrowley's Ridge is a north‐south trending erosional remnant of Coastal Plains sediments capped by multiple loess deposits. Due to activities of ancestors of the Mississippi and Ohio rivers, the extensive flood plains, both immediately east and west of this ridge, were plausible loess source areas. This long, narrow ridge was transected normal to its long axis to separate and investigate the multiple loess deposits and to determine the source area of each loess. Morphology, total Ca and K distribution, and clay distribution were used to differentiate the loess deposits. Particle size, expressed on the clay‐free basis, was used to determine the source area of each loess.Three loess deposits were identified on Crowley's Ridge. The surface loess is 2.8 to 7.4 m thick and contains the surface soil which has undergone sufficient development to form a fragipan. This loess was correlated as Peoria Loess and was deposited from the flood plain east of Crowley's Ridge. The middle loess shows evidence of weak soil development. This thinner, 1.3 to 1.8 m thick, loess was correlated as Roxana Silt and evidently also had its source in the flood plain east of Crowley's Ridge. The basal loess contains a strongly developed paleosol at its surface and ranges from 2.3 to 8.6 m thick. This deposit was correlated as Loveland Silt and apparently had been deposited from the flood plains on both the east and west sides of Crowley's Ridge.
Variability of Measured Properties in Morphologically Matched Pedons
Authors: Mausbach M. J. , Brasher B. R. , Yeck R. D. , Nettleton W. D. 
Published: July 2010

AbstractVariability in data from morphologically matched pairs of pedons was assessed to establish operational norms in sampling and to consider alternative sampling procedures.Coefficients of Variation (C.V.'s) were computed for the physical properties—percent sand, silt, clay, and 1,500 kPa moisture—and range from 9 to 40% for loess, 23 to 35% for glacial drift, 33 to 47% for alluvium and residuum, 18 to 32% for A and B horizons, and 33 to 51% for C horizons. C.V.'s were computed for the chemical properties—extractable acidity, sum of bases, cation exchange capacity (CEC), base saturation, pH, and organic carbon—and range from 12 to 50% for Alfisols, 4 to 71% for Aridisols, 6 to 61% for Entisols, 10 to 63% for Inceptisols, 9 to 46% for Mollisols, 16 to 132% for Spodosols, 10 to 100% for Ultisols, and 8 to 46% for Vertisols. Cation exchange C.V.'s are directly related to pH dependent charge.On the average, clay content for central concepts of phases of series can be estimated within ± 5% clay (95% confidence level) by 1 to 4 samples in loess soils, 2 to 8 samples in glacial drift soils, and 4 to 24 samples in alluvial and residual soils.Similar estimates of base saturation (sum of cations) within ± 10% (95% confidence level) require 2 samples for Aridisols and Vertisols; 5 for Mollisols; 10 for Alfisols, Ultisols, Entisols, and Inceptisols; and 16 for Spodosols.Vertical distribution of properties and properties of important horizons are efficiently evaluated by sampling one complete pedon plus satellite samples of important horizons from other pedons. To assess a single horizons efficiently, sample only that horizon in several pedons. Sampling of paired pedons is a good first approach technique to study soils in an area.
Silicate and Phosphate Adsorption on Gibbsite Studied by X‐ray Photoelectron Spectroscopy Angular Distributions
Authors: Alvarez Robustiano , Fadley Charles S. , Silva James A. 
Published: July 2010

AbstractA surface‐sensitive technique based on the angular distributions of X‐ray photoelectron intensities has been used to study the adsorption pattern of Ca, Si and P on gibbsite surfaces. The profile distributions of ions extending from the average Al(OH)3 surface plane appear to be in the order: Ca closer to the surface than Si for CaSiO3 as adsorbate and Ca at nearly the same plane and above Si for CaCl2 + Si(OH)4 as adsorbates irrespective of adsorbate pH. The average positions, relative to the Al(OH)3 atoms are: Si and P appear above the surface level when adsorbed from their respective acid forms, as is the case for more complex adsorbates like Si(OH)4 + H3PO4 + CaCl2, where Ca appears at the surface level. An atomic rearrangement on the gibbsite surface seems to occur in the latter case. These experiments have demonstrated that it is possible to apply the XPS (X‐ray photoelectron spectroscopy) angular distribution technique for adsorption studies on powdered soil materials, a subject of relevant interest in earth sciences.
Differential Bonding of Potassium and Rubidium‐86 in Soils of Differing Clay Type and Degree of Weathering
Authors: Eckert D. J. , McLean E. O. 
Published: July 2010

AbstractA Clermont silt loam and Paulding silty clay were amended with three levels of K and one level of 86Rb. The soils were moist‐incubated and leached with NH4OAc, followed by hot HNO3 extraction to remove more strongly bound cations. Both soils fixed added K against NH4OAc extraction, some of which K was also not quantitatively extracted by HNO3. The added 86Rb was found in NH4OAc extracts, HNO3 extracts, and in the soil residum following extraction. Addition of K to the Clermont soil forced 80Rb from the NH4OAc‐extractable fraction to a “sink” in this soil not accessible to either extractant. Adding K to the Paulding soil had the opposite effect. Independent reactions of K and Rb and the influence of soil type on K‐Rb interactions cast doubt on the possibility of using 86Rb as a tracer for K in soil systems.
Modification of Tempe Pressure Cell for the Measurement of Saturated Hydraulic Conductivities
Authors: Palmer Craig J. , Blanchar Robert W. 
Published: July 2010

AbstractThe Tempe pressure cell, which is used in studies of moisture retention, was evaluated for the measurement of saturated hydraulic conductivities. By the simple addition of a groove and O‐ring, the pressure cell was altered so that it would hold a vacuum. This modification allowed for complete saturation of the soil cores and prevented the adverse effects of entrapped air on the saturated hydraulic conductivity measurement. The ability of the cell to function in its original purpose was not altered. The multiple use of this cell may allow for monetary savings in equipment purchases.
A Comparative Electron Spin Resonance Study of VO2+ Complexation in Synthetic Molecules and Soil Organics
Authors: McBride M. B. 
Published: July 2010

AbstractThe vanadyl ion, VO2+, has been used as an ESR (electron spin resonance) probe of adsorption sites in pure organic complexing agents and natural peat to obtain information on the nature of the metal‐organic bond in soils. Oxygen ligands of soil organics displace on the average about two ligand H2O molecules from VO(H2O)52+ in forming an inner‐sphere complex with the metal. The bonding mechanism of natural organics is very similar to that of polycarboxylic acids such as uronic acid. Unlike soluble low molecular weight carboxylic acids, the solid polycarboxylates are not able to bond to all four equatorial ligand positions of VO(H2O)52+. Evidence is presented that Fe and Al in the soil organics occupy complexation sites and partially block VO2+‐carboxylate bond formation. The heterogeneous nature of natural organic complexing sites is demonstrated by the broadened nature of VO2+ ESR spectra when the metal is adsorbed on soil organics in comparison with pure polycarboxylic acids.
Relative Effect of Vesicular‐Arbuscular Mycorrhizal Fungi on the Growth and Yield of Soybeans
Authors: Carling D. E. , Brown M. F. 
Published: July 2010

AbstractThe growth and yield response of greenhouse‐grown soybean plants to colonization by 19 isolates (including 6 Glomus and 3 Gigaspora species) of vesicular‐arbuscular mycorrhizal fungi is reported. Each isolate was evaluated in a high (169 kg/ha Bray‐I P2O5) and a low (50 kg/ha Bray‐I P2O5) fertility soil. Colonization by most Glomus isolates significantly increased plant top dry weight and seed yields, and of these isolates most produced larger increases in dry weight in the low fertility soil. Colonization by five of the Gigaspora isolates did not significantly affect top dry weight and seed yield in the high or Iow fertility soil. The value of comparative testing of species is discussed.
Relation of Parent Material Geology to Reaction Classes of Flood Plain Entisols in the Coastal Plains
Authors: Perkins H. F. , Hutchins Ann 
Published: July 2010

AbstractSoil reaction class is a criterion used in classifying Entisols. A total of 122 pedons of alluvial Entisols were sampled in eight major geologic areas of the Atlantic and Gulf Coastal Plains. Soil reaction values were determined in water and 0.01M CaCl2. Geologic formation may be used to predict the soil reaction class at the family level when the formation is relatively uniform. Areas having highly dissected terrain are somewhat unpredictable.
Computerized Processing and Storing of Soil Descriptions and Characterization Data
Authors: Smeck Neil E. , Norton L. D. , Hall G. F. , Bigham J. M. 
Published: July 2010

AbstractIn Ohio, an interactive time‐sharing computer is utilized to process, store, and retrieve soil morphological, chemical, physical, and mineralogical data for pedons analyzed by the Ohio Soil Characterization Laboratory. Morphological information is coded into the computer using connotative abbreviations for soil parameters such as texture, structure, and color, while the computer is used to process this information into narrative‐like profile descriptions. Chemical, physical, and mineralogical data are stored either directly from calculations or entered from data sheets and printed out in a fixed format. The time involved preparing and editing morphological descriptions and soil data sheets has been reduced by as much as one half.
Field Determinations of Soil Hydraulic Properties for Statistical Analyses
Authors: Russo David , Bresler Eshel 
Published: July 2010

AbstractA procedure for repetitive determinations of soil hydraulic properties is based on the assumption that the functional relationships between soil water content (θ) and soil water pressure head (h), and between the hydraulic conductivity (K) and h, can be expressed mathematically. The parameters in the mathematical expression are: saturated hydraulic conductivity (Ks) and water content (θs), residual (or irreducible) water content (θr), water entry value of h (hw), and the parameters η and β, characterizing the pore size distribution of the soil. Values of Ks and hw are measured by the air‐entry permeameter of H. Bouwer. The parameters η and β were calculated with measured values of Ks, hw, θs, θr, and the sorptivity, S, as measured by C. Dirksen's method. The variability in the determination of the K(θ) function is evaluated in the field, from 30 measurements of each of the six parameters made in a single 2 by 2 m site. This variability is smaller than the variability of K(θ) as calculated from a simulation of a transient drainage. The K(h) and θ(h) functions are rapidly obtained and thus suitable for performing large numbers of measurements for the determination of the probability density functions (and joint probability density functions) of the soil hydraulic conductivity, K(θ), and soil water retentivity, h(θ), functions.
A Comparison of Column‐Displacement and Centrifuge Methods for Obtaining Soil Solutions
Authors: Adams Fred , Burmester Charles , Hue N. V. , Long F. L. 
Published: July 2010

AbstractFour soils, ranging in texture from loamy sand to clay, were fertilized differently and equilibrated moist for several days. Soil solutions were then separated by column‐displacement, by simple centrifugation, and by immiscible displacement with CCl4 via centrifugation. The ionic compositions of soil solutions were unaffected by the method used to obtain the solutions.
Computer‐Assisted Farmland Appraisal Systems
Authors: Doucette W. H. , Whiteside E. P. 
Published: July 2010

AbstractA computer‐assisted, farmland appraisal system (the Agvalue System) based on agricultural productive capacity was developed and analyzed. The heart of the Agvalue System is a computer‐generated land value map (LVM). The appraiser interprets the LVM, using a transparent overlay that portrays pertinent information not contained in the LVM, e.g., property boundaries and roads.Seven Agvalue System procedures were tested in a pilot study appraisal of 45 farmland parcels ranging in size from 4.32 to 40.0 ha (10.8 to 100.0 acres) in Alpine Township of Kent County, Mich. The Agvalue appraisal procedures tested consisted of seven different combinations of: (i) soil information sources (Series 1926, updated 1926, and 1973 soil maps), (ii) computed storage cell sizes (1 and 4 ha or 2.5 and 10.0 acres), and (iii) LVM interpretation methods (broken or full cell).The pilot study showed that all seven Agvalue System procedure values were highly correlated to the state of the art manual appraisal values using 1973 soil maps. The Agvalue System procedure employing 1973 soils information, 1 ha (2.5 acres) cells, and broken cell LVM interpretations most closely duplicated the manual appraisal values, r = 0.994. Even the 1926 soils information and 4 ha (10 acres) cell size were also found to be highly correlated to the manual procedure, r = 0.960, but with greater variance than the most accurate procedures.The Agvalue System essentially allows for the use of the Michigan State Tax Manual procedure en masse on all farms in a township at a cost of between $250 and $380 per year (1977 dollars) above 1977 expenditures. However, savings in appraiser's time more than offset these costs. Supplied with net income data, an Agvalue System can be used for an income approach to farmland appraisals.
Changes in Properties of a Newly Cleared Tropical Alfisol as Affected by Mulching
Authors: Lal R. , De Vleeschauwer D. , Nganje R. Malafa 
Published: July 2010

AbstractRapid deterioration in soil physical properties following deforestation for arable land use adversely affects crop production from soils in the humid and subhumid tropics. This investigation was conducted to determine whether the rate of deterioration can be minimized by the use of crop residue mulches. Changes in soil properties of a newly cleared tropical Alfisol resulting from mulch rates of 0, 2, 4, 6, and 12 tons ha−1 season−1 of rice (Oryza sativa) straw were investigated from 1976 to 1977. Total porosity, 18 months after initiating the experiment, was 48, 50, 55, 55, and 59%, respectively, for increasing mulch rate. Similarly affected were relative proportions of macropores, saturated hydraulic conductivities, field infiltration rates, and moisture retention at 0.1 and 0.3 bar suctions. Decrease in the maximum temperature was 3.3, 4.1, 4.5, and 5.4°C for 2, 4, 6, and 12 ton/ha mulch rates respectively, compared with the unmulched control. The water runoff was 18, 10, 4, 1, and 0% of the rainfall received for increasing mulch rates, respectively. The chemical fertility of the soil decreased with time after forest removal. However, the rate of degradation was less with increasing mulch rate. The rate of decline of organic matter content over the 18‐month period was 0.103, 0.100, 0.092, 0.083, and 0.078% per month for 0, 2, 4, 6 and 12 tons/ha of mulch, respectively.
Response of Semimature Slash and Loblolly Pine Plantations to Fertilization with Nitrogen and Phosphorus
Authors: Fisher R. F. , Garbett W. S. 
Published: July 2010

AbstractField trials to measure the response of semimature slash pine (Pinus elliottii var. elliottii Engelm.) and loblolly pine (Pinus taeda L.) in the southeastern U. S. lower coastal plain were established between 1968 and 1970 at 32 locations. Treatments consisted of N at 0, 55, 110, and 220 kg/ha, and P at 0 and 55 kg/ha in a complete factorial arrangement. Grouping sites on the basis of soil drainage class and depth to and nature of the B horizon served as an efficient way to interpret response to fertilization. After 8 years stands on most soils exhibited moderate to large volume gains when fertilized with N and P. Stands on wet soils with clay near the surface responded favorably to the addition of P alone.
Sodium Hypochlorite Treatment for Organic Matter Destruction in Tropical Soils of Nigeria
Authors: Omueti J. A. I. 
Published: July 2010

AbstractSupporting evidence for the universal usefulness of NaOCl in removing organic matter from soils is needed. Apart from its higher efficiency in organic matter destruction, NaOCl adjusted to pH 9.5 was found to be an effective dispersing reagent for savannah soils (which make up over 60% of the land area of Nigeria) during particle size analysis. The additional discovery of the use of NaOCl was considered to be very significant over the conventional H2O2 method where extra treatment with (NaPO3)6 was needed to obtain dispersion. However, in the case of fine textured forest soils it was found that for them to be in the dispersed state, additional washing with 2% aqueous Na2CO3‐HaHCO3 must be performed after the NaOCl pretreatment.
Application of Sewage Effluent to Columns of a Mountain Meadow Soil: I. Errors in Calculating the Transport of Ionic Salts
Authors: Barbarick K. A. , Klute A. , Sabey B. R. 
Published: July 2010

AbstractA series of soil columns was prepared using a device to ensure uniform packing. These columns were filled with the top 70 cm of the profile of a mountain meadow soil. All columns were leached with 0.01N CaSO4 and then irrigated for 12 weeks with sewage effluent from Hayden, Colorado. Two columns were destructively sampled each week to determine bulk density and the gravimetric moisture content. Porous cup extracts of the solution phase were obtained from seven depths in five columns, which were destructively sampled after 12 weeks of irrigation with the sewage effluent. The transport of ionic salts was calculated for the 9 weeks of steady‐state flow using the principle of mass conservation.An error analysis showed that the error terms were additive with depth and were the same order of magnitude as the calculated fluxes. The measurement of the electrical conductivity of the porous cup extracts provided the largest component of the error term. If an error of 0.05 mg/cm−2 day−1 is desired for a calculated salt flux of 0.5 mg/cm−2 day−1 for the bottom 10‐cm increment of a 70‐cm column, the electrical conductivities would have to be measured to the nearest 0.003 mmho/cm.