bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silicic Acid and Oxidizable Carbon Movement in a Walla Walla Silt Loam as Related to Long‐Term Management
Authors: Douglas C. L. , Allmaras R. R. , Roager N. C. 
Published: July 2010

AbstractAgricultural ecosystems can alter the natural soil‐forming process, but little information is available to project the effects. Such alterations can be recognized early in soils that have little natural horizon differentiation, such as the Walla Walla silt loam (coarsesilty, mixed, mesic Typic Haploxeroll). The potential for movement of silicic acid (H4SiO4) and soluble organic carbon (C) was evaluated in selected plots subjected to residue and nitrogen (N) addition treatments for a period of 50 y. Soil samples from the four upper 15‐cm layers of a plot, assembled as a column, were leached and simultaneously monitored for solubilization and movement of H4SiO4 and oxidizable organic C. Leachate concentrations and net transfers of H4SiO4 from the 0‐ to 15‐cm layer decreased as long‐term C additions increased, soil pH increased, or both. High concentrations of H4SiO4 were noted throughout the upper 60 cm, which confirms earlier observations using perfusion and batch equilibration techniques. The large concentrations of soluble organic C and their failure to correlate with H4SiO4 movement indicated that soluble organic C was not controlling solubilization of sorbed silica. Liming decreased the release of soluble H4SiO4 from the 0‐ to 15‐cm layer. All soluble H4SiO4 observations were consistent with silicic acid release from surfaces that could be partially covered (or otherwise deactivated) by coatings of organic materials. The decrease in H4SiO4 solubilization by either liming or a high organic matter level should be examined further as a possible mechanism involved in the beneficial effects of these two managements on soil structure and physical properties.
Properties of Minesoil Reclaimed for Forest Land Use
Authors: Bussler B. H. , Byrnes W. R. , Pope P. E. , Chaney W. R. 
Published: July 2010

AbstractPhysical and chemical properties of minesoil reclaimed for forest land use in southwestern Indiana were evaluated to determine suitability for reforestation according to specifications of Public Law 95–87, The Surface Mining Control and Reclamation Act of 1977. Properties of reconstructed minesoil and unmined reference soils were compared. Soil types on the reference area were primarily Ava (Typic Fragiudalf) and Parke (Typic Hapludalf) silt loams and were similar to soils on the mineland prior to excavation. Both the reclaimed mineland site and reference site supported mixed upland hardwood trees and shrub vegetation prior to surface mining. Chemical properties of minesoil were similar to or more favorable for plant growth than unmined reference soils. However, physical properties in the rooting zone were less favorable in minesoil than reference soils. Minesoil had higher bulk density, lower porosity, lower permeability, higher coarse fragment and clay content, and lower available water‐holding capacity than reference soils at comparable depths. Mean bulk density of minesoil, adjusted for rock fragments > 2 mm, ranged from 1.53 Mg m−3 (g cm−3) in topsoil to 1.77 Mg m−3 in graded cast overburden. Mean available water‐holding capacity was 16.5% in topsoil and 10.8 to 11.7% (kg kg−1) in graded cast overburden layers of minesoil. Chemical properties of minesoil should be adequate for cover crop and tree seedling establishment after liming and fertilization to recommended soil test levels of NPK. However, physical properties could adversely affect plant survival and growth.
Soil Nitrogen Availability following Long‐Term Burning in an Oak‐Hickory Forest
Authors: Vance Eric D. , Henderson Gray S. 
Published: July 2010

AbstractSeasonal levels of extractable ammonium and nitrate in the surface soil of oak‐hickory (Quercus spp. and Carya spp.) forest plots subjected to 30 yr of annual and periodic (4‐yr) prescribed burning were studied. Laboratory incubations were also carried out for 4‐, 14‐ and 28‐d periods at each of six dates to determine the effect of the burning treatments on mineralizable N. Ammonium was the predominant N form regardless of treatment. Burning significantly (P = 0.05) reduced quantities of extractable NH+4 over all sampling dates, with annual burning resulting in lower amounts than burning every 4 yr. Burning also significantly reduced the quantity of N mineralized during incubation. Since previous studies have not shown decreases in total N on the burned plots, the lower extractable N concentrations appear to be the result of an adverse effect of long‐term burning on substrate quality that reduced rates of mineralization. The treatment influence on mineralizable N was more apparent during the latter 24 d of laboratory incubation, whereas the initial 4 d reflected the influence of sampling date to a greater degree. From this pattern, it is hypothesized that the initial 4 d of incubation are more indicative of field environmental conditions, whereas the latter 24 d reflect the quantity of mineralizable substrate present. Although treatment differences in extractable and mineralizable N were statistically significant overall, the lack of statistical differences at some dates indicates the importance of seasonal sampling.
Sulfur‐Coated Urea for Turfgrass Fertilization
Authors: Hummel N. W. , Waddington D. V. 
Published: July 2010

AbstractThe acceptance of sulfur‐coated urea (SCU) as a fertilizer in the turfgrass industry requires a firm basis on which to make recommendations for its use. Three SCU materials were evaluated at different rates and timing of application for maintenance fertilization of ‘Merion’ Kentucky bluegrass (Poa pratensis L.). Two were SCU materials from the Tennessee Valley Authority (TVA): SCU‐11 and SCU‐25, having 11 and 25% 7‐d dissolution rates, respectively. The third, CIL‐30 (30% dissolution rate), was SCU prill from Canadian Industries Limited (CIL). Ammonium nitrate (AN), ureaform (UF), and isobutylidene diurea (IBDU) were also evaluated for comparison with SCU. Response to fertilization was measured by weekly determinations of clipping yields and color. Nitrogen recovery in the clippings and residual SCU pellets in the turf stand were also determined. Data were collected for three growing seasons.The most uniform turfgrass response to SCU fertilization was produced by split applications of 245 kg N ha−1 y−1; and response to SCU‐11 was less than that to SCU‐25 and CIL‐30. When SCU‐25 and CIL‐30 were applied at a rate of 245 kg N/ha in single fall applications, there was insufficient carry‐over of residual N to maintain dark color throughout the growing season. During the first 2 y, release of N from SCU‐11 tended to be too slow to maintain good season‐long color, with only the single spring application of 245 kg N/ha maintaining good color throughout the summer. Response improved in the third year. Fertilization rates of 147 kg N ha−1 y−1 did not produce acceptable quality turf.Pellet recovery from the turf was inversely related to N recovery in plant tissue. Two months after application, SCU dissolution ranged from 91 to 97% for CIL‐30, 60 to 80% for SCU‐25, and 38 to 53% for SCU‐11. Recovery of applied N in the clippings was highest for AN and CIL‐30 with 49 to 59% and 50 to 56% recovery, respectively. Nitrogen recoveries of 42 to 52% and 25 to 37% were obtained for SCU‐25 and SCU‐11, respectively. Recovery was 22% for UF and 46% for IBDU. Response to IBDU compared favorably to SCU‐25, while response to UF was less than from any other 245‐kg split treatment.
Short‐Term Immobilization of Fertilizer Nitrogen at the Surface of No‐Till and Plowed Soils
Authors: Rice Charles W. , Smith M. Scott 
Published: July 2010

AbstractImmobilization of (NH4)2SO4 in no‐till and conventionally tilled soils was monitored after application of 15N enriched material to the surface of 20‐cm diameter plots on three soil types. Soils were collected periodically up to 35 d and 15N in organic and inorganic fractions was measured. On all three soils there was more immobilization in no‐till. After 35 d, the percentage of fertilizer applied that was immobilized was 21 and 11 on Maury silt loam, 13 and 6 on Tilsit silt loam, and 24 and 15 on Cavode silt loam for no‐till and conventional tillage, respectively. There were no consistent trends or statistically significant differences between tillage treatments with regard to total N recovery (organic plus inorganic). The increased potential for immobilization of N at the surface of no‐till soils may significantly reduce crop recovery of fertilizer N.
Organo‐Mineral Complexes and Their Study by Radiocarbon Dating
Authors: Anderson D.W. , Paul E.A. 
Published: July 2010

AbstractThe objective of this study was to investigate the long‐term cycling of organic C in cultivated soils by radiocarbon dating. Samples from a clayey Haploboroll soil (Indian Head) taken in 1963 and 1978 showed a general reduction in radiocarbon age of the whole soil of 20%. This was attributed to the enrichment of 14C in the atmosphere because of nuclear explosions in the 1960s, and its subsequent incorporation into organic matter. Relative decreases in age were least for nonhydrolyzable C and the aromatic HA‐A, the oldest and least active fractions. The apparent age of the humin and clay‐associated HA‐B decreased much more, indicating their greater involvement in short‐term cycling. A second clayey Haploboroll soil (Melfort) was studied by chemical fractionation and separation into size fractions after ultrasonic dispersion. The HA‐A and coarse clay‐associated organic C were oldest, with a much younger date for fine‐clay‐associated organic C. Fulvic acids purified by dialysis to eliminate materials less than 2000 molecular weight had an old date of 1140 ± 35 yr. Size fractionation of two other Boroll soils indicated young radiocarbon ages (radiocarbon enrichment) of fine clay‐associated organic C. These findings are discussed in terms of the cycling of organic matter and nutrients. Particular attention is given to clay‐humus interactions and their importance in protecting otherwise labile humic materials to provide a substantial pool of moderately available nutrients.
Effectiveness of Phosphoroamides for Retardation of Urea Hydrolysis in Soils
Authors: Martens D. A. , Bremner J. M. 
Published: July 2010

AbstractThe effectiveness of two phosphorodiamides (phosphorodiamidic acid, phenylphosphorodiamidate) and 10 phosphorotriamides [(N‐phenylphosphoric triamide, N‐(4‐nitrophenyl)phosphoric triamide, N‐(diaminophosphinyl)benzamide, 4‐cyano‐N‐(diaminophosphinyl)benzamide, N‐(3‐trifluoromethylphenyl)phosphoric triamide, N‐(diaminophosphinyl)‐3‐pyridinecarboxamide, 4‐chloro‐N‐(diaminophosphinyl)benzamide, 4‐fluoro‐N‐(diaminophosphinyl)benzamide, N‐(diaminophosphinyl)benzeneacetamide, and phosphoric triamide] for retardation of urea hydrolysis in soils was studied by determining the effects of 10 µg g−1 soil of each compound on the amounts of urea hydrolyzed when soils treated with urea were incubated at 20°C for 3, 7, and 14 d. The soils used were selected to obtain a wide range in properties, and the effects of the 12 phosphoroamides studied were compared with those of five compounds known to be among the most effective of the compounds thus far proposed for retardation of urea hydrolysis in soils (hydroquinone, catechol, 1,4‐benzoquinone, 2,5 dichloro‐1,4‐benzoquinone, and phenylmercuric acetate). The data obtained showed that most of the phosphoroamides studied were as effective as the compounds used in this comparison and that phenylphosphorodiamidate was considerably more effective than all other compounds studied.
Effects of Nitrogen Fertilization on Manganese Concentration and Yield of Barley and Oats
Authors: Petrie S. E. , Jackson T. L. 
Published: July 2010

AbstractResponse of barley (Hordeum vulgare L.) and oats (Avena sativa L.) to band application of N sources with and without Mn and the effects of band vs. broadcast application of fertilizers on the Mn concentration in leaves and yield of barley and oats were studied in the field in 1978, 1979, and 1980 on Lower Klamath Lake where Mn deficiency of oats had been observed in previous years. Experiments were established on a Tulana silt loam variant (medial, nonacid, mesic, Mollic, Andequepts). The pH of the soils ranged from 7.6 to 8.3 and the organic matter content was between 17 and 19%. Nitrogen was applied at 0, 22, or 45 kg N/ha as (NH4)2SO4, NH4Cl, urea, and various urea‐phosphate (UP) formulations. Manganese was applied at 0 or 5.6 kg Mn/ha as MnSO4. All treatments received P at 19 kg P/ha as Ca(H2PO4)2 or 25 kg P/ha in the UP fertilizers, and Cu as CuSO4 at 2.2 kg Cu/ha in 1978 and 5.6 kg Cu/ha in 1979 and 1980. ‘Cayuse’ oats and ‘Steptoe’ barley were planted at 110 kg/ha. Band application with the seed of 22 or 45 kg N/ha as (NH4)2SO4 or NH4Cl significantly increased both barley and oat leaf Mn concentrations and yields all 3 yr. Leaf Mn concentrations and yields were not increased by urea fertilization. When Mn was applied with the N fertilizer, leaf Mn concentrations and yields were similar regardless of N source. Broadcast application of fertilizers did not increase leaf Mn concentration or yield. The UP materials were intermediate in effectiveness between urea and (NH4)2SO4.
Toposequence of Oxisols from the Central Plateau of Brazil
Authors: Curi N. , Franzmeier D. P. 
Published: July 2010

AbstractLandscape position is a critical factor influencing many co‐varying soil properties even in highly weathered soils that tend to have a high degree of homogeneity. The objective of this study was to learn how the position of a soil in a toposequence influences soil color, mineralogy, and some chemical and physical properties.In a toposequence of Oxisols developed from basalt in the Central Plateau of Brazil (Goias State), moist soil color changed from dark reddish brown (2.5YR 3/4) in upper slope positions to dark yellowish brown (10YR 4/4) in lower slope positions and the following trends were observed: hematite content decreased and goethite content increased, the amount of Al substitution in the goethite structure increased, gibbsite content decreased and kaolinite content increased, and magnetic suceptibility and maghemite content of fine clay decreased. Also, the yellower soils down slope adsorbed more P and desorbed less P than the redder soils upslope, possibly because the yellower soils contain more goethite, which was found to have a smaller crystallite size and more DCB‐extractable Al than hematite. Soil color is a reliable indicator of iron oxide mineralogy which reflects the genesis of the soil and influences properties that affect plant growth. Thus, color should be used at a relatively high categorical level in soil classification systems to define classes of Latosols and Oxisols.
Characterization and Evaluation of Agricultural Benchmark Soils from Sevilla, Spain
Authors: de la Rosa D. , Mudarra J. L. , Romero R. , Martin‐Aranda J. 
Published: July 2010

AbstractIn Sevilla Province, southwestern Spain, benchmark soils of eight agricultural areas were defined using traditional soil pedon concepts of soil survey. The characterization emphasized morphological, chemical, and physical analyses. These eight representative soils were classified as follows: Rojo Aljarafe (Typic Rhodoxeralf), Tierranegra Campo (Typic Pelloxerert), Salino Marismas (Vertic Fluvaquent), Franco Vega (Typic Xerofluvent), Arena Terrazas (Aquic Haploxeralf), Almagra Alcores (Calcic Haploxeralf), Bujeo Campiña (Typic Chromoxerert), and Albariza Estepa (Entic Haploxeroll). By application of a computer‐based soil evaluation system developed with information from a representative zone, predicted yields were calculated for wheat (Triticum aestivum L.), field corn (Zea mays L.), and cotton (Gossypium hirsutum L.) for the selected benchmark soils. Productivity information was transferred from the representative zone to the eight agricultural areas within Sevilla Province. Soils were ranked in the following order according to predicted yields for the three crops: Bujeo Campiña > Tierranegra Campo > Franco Vega > Salino Marismas > Rojo Aljarafe > Almagra Alcores > Albariza Estepa > Arena Terrazas.
Formation of Aluminum‐Substituted Goethite in Seasonally Waterlogged Rice Soils
Authors: Karim Zahurul 
Published: July 2010

AbstractThree soils (Aeric Fluvaquentic Haplaquepts, Fluvaquentic Haplaquepts, and Rhodic Paleudults) were collected from three different typical paddy fields in Bangladesh. Goethite was the only crystalline hydrous iron oxide identified by X‐ray diffraction, ranging in amount from approximately 4.78 to 12.05 mg g−1 of soil. Aluminum substitution for iron in the soil goethites ranged from 5.38 to 12.69 mole %, the largest amount being in Fluvaquentic Haplaquepts. A probable process of formation of the soil goethite is discussed. Aluminum‐substituted goethite was synthesized in simulated rice paddy conditions by the oxidation of Fe(II) solution in the presence of Si and Al. Synthetic goethites contained 3.8 to 6.4 mole % Al in their structures.
Evaluation of Aluminum‐Smectite Stability Equilibria in Naturally Acid Scoils
Authors: Karathanasis A.D. , Hajek B. F. 
Published: July 2010

AbstractStability characteristics of six Al‐smectites in naturally acid (pH < 5.0) montmorillonitic soils were determined by using structural ionic constituents and in situ soil solution compositions. Approximate solubility products (pk) for each smectite were calculated from δG0t values of hydroxide counterparts of cation structural components. Calculated ion‐activity products (pQ) of soil solutions were approximately equal (within the range of analytical uncertainties) to extimated pks of smectites in three of six soils. The other three solutions were either supersaturated (C horizon) or undersaturated (Bt horizons) relative to smectite. Solutions obtained from C horizons were supersaturated with respect to amorphous silica due to dissolution of biogenic opal and albite. In these borizons, where large quantities of smectite have been preserved, smectite stability appeared to be enhanced by high solution levels of Si and Mg. Low ratios of solution Si/Al in A and B horizons, where not compensated by relatively high pH, promoted weathering of smectite to kaolinite. Standard free energies of formation (δGot for Al‐smectites, computed from estimated pk values, ranged from −10 161 ± 1021 to −10 345 ± 1040 kJ/mol. The highest δof values were encountered in smectites with the most structural OH‐.
Influence of Mine Tailing Particle Density on Pipette Procedures
Authors: Shetron S. G. , Trettin C. C. 
Published: July 2010

AbstractWater displacement and pycnometer determined particle densities were calculated for a variety of mine mill waste materials. Generally, both procedures were in agreement with each other. However, water displacement particle densities were slightly less than pycnometer determined particle densities. Particle densities for several kinds of mine mill wastes range from 2.51 to 3.77 Mg m−3. When compared to their mineralogical species composition, particle density values reflected the specific gravity of the dominant mineral found in the mine wastes. As a result of the range in particle densities, time and depth sampling for pipette determined 20 µm and 2 µm size fractions were adjusted to compensate for the variability in mine waste particle densities.
Determination of Ionic Activities in Soil Solutions and Suspensions: Principal Limitations
Authors: Amacher M. C. 
Published: July 2010

AbstractA review of the theoretical and experimental limitations of the measurement and calculation of ionic activities in soil solutions and suspensions was conducted. Ion‐selective electrode methods, ion speciation models, and metal ion‐chelate equilibria methods were reviewed. The lack of sensitivity, the presence of numerous interferences, and the existence of liquid junction potentials can severely limit ion‐selective electrode methods. The completeness of the ion speciation model and the reliability of the analytical data and the species formation constants greatly affect the quality of the results of this approach. The failure of the chelate and trace metal ions to reach equilibrium with a specific solid phase in the soil in a reasonable time period limits the metal ion‐chelate equilibria methods. Further work is needed to identify and overcome limitations in the determination of ionic activities in soil solutions and suspensions.
Prediction of Ion Activities in Soil Solutions: Computer Equilibrium Modeling
Authors: Baham John 
Published: July 2010

AbstractModeling of a multicomponent natural water system, such as the soil solution, utilizing classical ion association equilibria, allows one to estimate thermodynamic activities for many chemical species for which direct measurement is either not practical or impossible. A number of computer‐based equilibrium models are presently available for use in soil chemical research. The thermodynamic formalism employed by all of the models is very nearly identical; however, small differences in the estimation of activity coefficients and temperature correction of thermodynamic data exist between models. The sophistication of the numerical routines used to obtain solutions of the problem can also vary between models. These differences are reflected in computational efficiency, but give rise to little or no difference in th epredicted activities.The selection, extent, and flexibility of the user‐supplied thermodynamic data file (TDF) is the major difference between geochemical models. After the total concentrations of metals and ligands, temperature, and pressure are specified, equilibrium constants for all complexes allowed to form are retrieved from the TDF. The selection of a TDF, therefore, specifies the equilibrium problem to be solved. The compilation of a critically reviewed TDF for use in soil chemistry is the most important component in the attempt to model soil solution geochemistry at equilibrium.Some recent uses of geochemical modeling of the rhizosphere have been selected from the literature to demonstrate the utility of this approach.
Influence of Long‐Term Tillage and Crop Rotation Combinations on Soil Enzyme Activities
Authors: Dick W. A. 
Published: July 2010

AbstractThe effects of long‐term no‐tillage practices on the activity of enzymes in soil are not well understood. Soil profile (0–30 cm) samples were collected from plots where various tillage and rotation combinations had been continuously applied to a Hoytville silty clay loam (Mollic Ochraqualfs) soil (18 yr) and a Wooster silt loam (Typic Fragiudalfs) soil (19 yr). With the exception of alkaline phosphatase activity in the Wooster soil, results indicate that the activities of acid phosphatase, alkaline phosphatase, arylsulfatase, invertase, amidase, and urease in the 0 to 7.5‐cm profile increment were significantly (P < 0.05) higher where no‐tillage (NT) compared to conventional tillage (CT) practices had been maintained. Below the 7.5‐cm depth, the effect of tillage on the enzyme activities varied with the soil and/or the enzyme studied. Enzyme activities in the 0 to 7.5‐cm profile increment in the NT plots were significantly affected by rotation with the highest activities observed for the corn (Zea mays L.)‐oats (Avena sativa L.)‐alfalfa (Medicago sativa L.) rotation and the lowest for the corn‐soybeans (Glycine max L.) rotation. The results observed for the effect of tillage and rotation on soil enzyme activities were strongly correlated with organic C concentrations. From 78 to 92% of the total variation in enzyme activities observed for the Wooster soil profile could be accounted for by organic C concentrations. For the Hoytville soil from 28 to 83% of the variation could be accounted for by organic C concentrations. Including pH in a multiple regression model increased the total variation of the alkaline phosphatase, arylsulfatase, and urease activities which could be explained in the Hoytville profile from 28 to 1%, 28 to 57%, and 41 to 59%, respectively.