bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Temperature‐dependent Hydraulic Properties on Soil Water Movement
Authors: Hopmans J. W. , Dane J. H. 
Published: July 2010

AbstractThermal effects on the soil water regime are often ignored. In addition to the effects of temperature on the driving forces for flow, there are also direct thermal effects on the soil's hydraulic properties. Accounting for this temperature dependency of the soil's hydraulic properties, the pressure head form of the general flow equation of water was solved by the predictor‐corrector method for different temperature regimes and for a variety of initial and boundary conditions. Corrections of soil hydraulic properties due to temperature changes were either based on experimental data extracted from the literature or on theoretical considerations. Temperature effects were found to be much more pronounced for a pressure head than for a flux boundary condition at the soil surface. For temperature varying with both time and depth, the effect seemed to be minimal if the hydraulic properties were determined at the mean temperature of the profile. The latter suggests that soil hydraulic properties determined in the laboratory, but to be used for field conditions, should probably be determined at a temperature that approaches the mean field soil temperature. The simulations also showed that temperature effects are more pronounced as the temperature coefficient of soil‐water‐pressure‐head increases, but that the kind of effect depends on whether the existing temperature is above or below the reference temperature (temperature at which the hydraulic properties were determined).
Fertilizing Agricultural Land with Rainbow Trout Manure for Growing Silage Corn
Authors: Smith J. H. 
Published: July 2010

AbstractField plots on a Portneuf silt loam (mesic, Durixerollic Calciothids) were fertilized with fish manure at 0, 200, 500, or 800 kg N/ha or NH4NO3 at 0, 100, 200, and 300 kg N/ha for one, two, or three years and planted to corn (Zea mays L.) for four consecutive years. Corn silage yields up to 24 Mg/ha (dry weight) were obtained the first season in 1979 with no significant differences because of the high residual fertility. Highly significant yield increases were obtained the second, third, and fourth season from manure or NH4NO3. The yields were somewhat lower than those obtained the first season. In four years of cropping to corn with manure applied for the first three crops, N recovery for the manure treatments was 18, 28, and 24% of applied manure N for the 200, 500, and 800 kg N/ha applications for three years. In comparison treatments using NH4NO3, N recovery was 90, 59, and 57% for the 100, 200, and 300 kg N/ha treatments. The manure applications at 500 kg N/ha provlded enough N for high corn silage yields and were about equal to the yields obtained with 200 kg N/ha as NH4NO3. Residual N fertility from the manure was greater than from NH4NO3.
Effect of Preplant Wheel Traffic on Soil Compaction, Water Use, and Growth of Spring Wheat
Authors: Voorhees W. B. , Evans S. D. , Warnes D. D. 
Published: July 2010

AbstractThe effects of wheel traffic on small grain emergence and early growth is commonly observed in production fields. However, the plant response is not consistent, but appears dependent on soil and climatic conditions. The objective of this study was to measure the effects of preplanting wheel traffic on soil compaction and ‘Era’ spring wheat (Triticum aestivum L.) growth in field plots in West Central Minnesota under a range of growing season conditions. The 1975 and 1977 growing season were slightly wetter than normal while the 1976 growing season was significantly drier. Treatment comparisons were wheat planted in soil compacted by wheel traffic during spring field operations and wheat planted in soil that had not been wheel trafficked. Normal field‐sized equipment (tractor weight ranged from 4000 to 7000 kg) was used to perform spring fertilizer application, spring tillage, and seeding. The controlled wheel traffic concept was used. In 1975, wheat emergence in the wheel‐tracked soil was delayed by about 10 d because of poor seed‐soil contact, and grain yield was 27% lower than in the nontracked soil. Shortly after planting in 1976, the nontracked soil lost excessive amounts of water by evaporation from the loose 0‐ to 0.15‐m layer. As a result, wheat growth in the wheel‐tracked soil was better than in the nontracked soil, and yield was increased by 53%. In both 1975 and 1976, there was slightly more water used from the wheel‐tracked treatment than from the nontracked treatment, resulting in differences in water use efficiency. Effects of wheel traffic on wheat growth and yield were closely related to growing season precipitation and illustrate the need to consider probable climatic conditions when developing management systems for controlling field vehicular wheel traffic.
Ammonium Nitrogen Movement in a Coarse‐Textured Soil Amended with Zeolite
Authors: MacKown C. T. , Tucker T. C. 
Published: July 2010

AbstractLeaching of NH+4 from coarse‐textured soils treated with nitrification inhibitors is affected by the soil cation exchange capacity (CEC), the presence of other ions, and the percolation rate. Natural zeolites have unique chemical and physical properties that could enhance the retention of monovalent cations in coarse‐textured soils.Column experiments to evaluate NH+4 movement in Rositas loamy sand (Typic Torripsamment) amended with erionite (E) or clinoptilolite (K) natural zeolite at rates of 0, 12.5, 25.0 and 50.0 g zeolite kg−1 soil were conducted. Water saturated soil‐zeolite mixtures (1.0 kg) received 200 mg NH+4‐N and were leached with 3.0 liters (150 cm) of deionized water containing a nitrification inhibitor [2‐chloro‐6‐(trichloromethyl) pyridine]. Total NH+4‐N leached ranged from 168.4 mg N for the unamended soil (CEC = 29 cmol(+) kg−1) to 11.6 mg N for the 50.0 g E kg soil (CEC = 102 cmol(+) kg−1). Total effluent NH+4‐N at a given amendment rate was less from zeolite E(CEC = 1570 cmol(+) kg−1) than zeolite K (CEC = 1140 cmol(+) kg−1). The distribution of NH+4 recovered in 5‐cm increments was dependent on the CEC of the soil‐zeolite mixture. As the CEC increased, the depth of maximum accumulation decreased. These results indicate that zeolites effectively enhanced the retention of NH+4 subject to leaching and zeolite application per unit soil volume may be maximized by restricting the depth of incorporation.
Nitrification Inhibition by Nitrapyrin and Volatile Sulfur Compounds
Authors: Maddux L. D. , Kissel D. E. , Ball J. D. , Raney R. J. 
Published: July 2010

AbstractNitrification inhibitors can slow the rate of nitrification in soils and reduce nitrogen losses under some soil‐climatic conditions. Carbon disulfide (CS2) and compounds which produce CS2 have slowed nitrification in laboratory studies, but these compounds have not been tested extensively in the field. Therefore, field studies were conducted on irrigated corn (Zea mays L.) in 1978 and 1979 to evaluate inhibition of nitrification by CS2 at 5.6, 11 and 22 kg ha−1, sodium trithiocarbonate (STC) at 11 and 22 kg ha−1, ammonium dithiocarbamate (ADTC) at 11 and 22 kg ha−1, and potassium ethyl xanthate (KEtX) at 5.6 and 11 kg ha−1 as compared to nitrapyrin (2‐chloro‐6‐(trichloromethyl)‐pyridine) at 5.6 kg ha−1. Anhydrous ammonia was knifed 15 to 20 cm deep on 60 cm spacings at rates of 84, 168, and 252 kg N ha−1. All materials were evaluated on a Eudora fine sandy loam (Fluventic Hapludoll, coarse, silty mesic) in 1979 and CS2 and STC were evaluated on the same soil in 1978 and on two additional soils in 1979: a Pratt loamy fine sand (Psammentic Haplustalf, sandy, mixed, mesic) and a Crete silty loam (Pachic Argiustoll, fine, montmorillonitic, mesic). The performance of STC and CS2 in 1978 and 1979 indicated that these materials were not effective in inhibiting nitrification under the conditions that existed at the locations where they were applied. ADTC and KEtX were not effective inhibitors of nitrification, although they were only tested at one location in 1979. Nitrapyrin was effective in inhibiting nitrification in all studies. However, it resulted in an increase in corn yield only once—the fall N application on the Pratt loamy fine sand. The lack of yield response was attributed to the absence of conditions conducive for losses of nitrate nitrogen.
Distribution of Palygorskite in Sediments and Soils of Eastern Saudi Arabia
Authors: Shadfan Harbi , Mashhady A.S. 
Published: July 2010

AbstractRock samples representing different soil parent materials from the Jurassic, Cretaceous and Tertiary periods in eastern Saudi Arabia were investigated for their mineralogical and chemical properties. Samples from five soil profiles found on these rocks also were studied. Palygorskite was found to be the dominant mineral in the clay fraction of the Tertiary and upper Cretaceous sediments. Some shales of Tertiary origin contained mainly palygorskite with minor amounts of gypsum and soluble salts. Palygorskite was not found in any sediments of the early lower Cretaceous and Jurassic periods, and kaolinite was the dominant mineral in the clay fraction of those sediments. Soils associated with Jurassic limestone near the Riyadh area also showed a predominance of kaolinite in their clay fractions. However, the clay fractions of the soils found on Tertiary sediments in the eastern part of the country were dominated by palygorskite. The presence of palygorskite in the soils paralleled its presence in the parent materials or the rocks exposed in the area. Eolian transport of palygorskite was found to be a factor for the occurrence of palygorskite in the soils. Thus, the major portion of the soil palygorskite probably originated from the Tertiary sediments in eastern Saudi Arabia.
Nature and Behavior of Montmorillonite in an Acid Inland Marine Shale from East Central Saskatchewan
Authors: Curtin D. , Mermut A. R. 
Published: July 2010

AbstractThe mineralogy and chemistry of an acid clayey Cretaceous marine shale outcropping near Arborfield in east central Saskatchewan were studied. pH values as low as 3.6 and levels of exchangeable Aluminum of up to 28 cmol(+).kg−1 were recorded in this material. Clay separates of the shale were monomineralic, consisting of highly crystalline smectite (montmorillonite) with an average composition: M+0.71 (Si7.74Al0.26) (Al3.44Fe3+ 0.12Mg0.45)O20(OH)4 Ion activity product values, calculated from saturation extract composition data, indicated that the montmorillonite is stable despite the intense acidity of the shale. The high pH values (up to 8.5) which were observed in the upper soil horizons overlying the shale are due to the incorporation, by glacial action, of calcareous till into the shale. This till was apparently the source of the mica, kaolinite, and quartz present along with the montmorillonite in clays isolated from the upper horizons. The implications of the findings to the genesis and chemical characteristics of Saskatchewan soils are discussed.
Surface Soil Water Content Measurement Using Pulsed Nuclear Magnetic Resonance Techniques
Authors: Paetzold R. F. , Matzkanin G. A. , De Los Santos A. 
Published: July 2010

AbstractA tractor‐mounted pulsed nuclear magnetic resonance (NMR) moisture measurement instrument has been developed and fabricated for use in collecting ground truth data for calibrating and evaluating remotely sensed determinations. The measurement approach is based upon NMR which depends on the interaction between hydrogen nuclear magnetic moments and a magnetic field. The sensor unit, consisting of an electromagnet, detection coil, and tuning capacitor, is towed behind the tractor and provides continuous readout of the volumetric soil water content at selected depths to 63 mm. Preliminary laboratory measurements with this instrument on two soils, a clay and a loamy fine sand, correlate linearly with volumetric soil water content. Discrimination of water NMR signals from signals from other hydrogen‐bearing material is based on nuclear relaxation times, which reflect the molecular environment and structural bonding characteristics of the water molecules in the soil.
Fluoride Sorption and Desorption in Soils
Authors: Peek Daniel C. , Volk V. V. 
Published: July 2010

AbstractFluoride sorption and desorption reactions in 10 soils were investigated. Fluoride sorption kinetic data were obtained by equilibrating 1.0 mmol/L NaF solutions with four soils for periods from 1 h to 77 d. Fluoride sorption reactions with respect to soil properties were examined by equilibrating 0.0 to 2.5 mmol/L NaF solutions with 10 soils for 24 h. Fluoride sorption was rapid in all soils, with 90% of the sorption occurring within 24 h. Increasing sorption equilibration time decreased the amount of F that could be desorbed from the soil in 24 h. Fluoride sorption conformed to the Langmuir sorption isotherm for all soils over limited concentration ranges. The Freundlich sorption isotherm was applicable over the entire initial F concentration range (0.0–2.5 mmol/L) for all soils. Simple and multiple regression techniques allowed various F sorption parameters to be predicted from selected soil properties. Oxalate‐extractable Fe and Al, dithionite‐extractable Al and soil pH correlated most highly with both Langmuir b and Freundlich K values in a simple regression model. A multiple regression equation including oxalate‐extractable Al, clay, and oxalate‐extractable Fe predicted 90% of the variation in Langmuir b values. Fluoride desorption also conformed to the Freundlich isotherm for all soils. Fluoride desorption was hysteretic in 7 of 10 soils, but hysteresis could not be explained by differences in measured soil properties.
Direct Measurement of Oxygen Profiles and Denitrification Rates in Soil Aggregates
Authors: Sexstone Alan J. , Revsbech Niels Peter , Parkin Timothy B. , Tiedje James M. 
Published: July 2010

AbstractAn oxygen microelectrode was modified to measure O2 concentrations in wet aggregates of a silt loam soil. The microelectrode tip had an O2‐permeable membrane opening 3 µm in diameter, and O2 measurements could be made in as little as 0.1‐mm increments to a depth of 12 mm. When aggregates were incubated in air, steep O2 gradients usually occurred over very small distances from the aggregate surface. The smallest aggregate exhibiting an anaerobic center had a radius of 4 mm, although small aggregates (radius ≤ 6 mm) were generally oxic. Larger aggregates (radius ≥ 10 mm) often had measureable anaerobic centers, with the exception of those from a native prairie soil which exhibited irregular O2 profiles and had aerobic centers, apparently due to O2 intrusion caused by old root channels. Oxygen profiles obtained in 45 degree increments around an aggregate circumference were used to construct contour maps of O2 concentrations within the aggregate. Oxygen gradients were somewhat asymmetric, suggesting nonuniformly distributed sites of O2 consumption. An average intra‐aggregate O2 diffusion coefficient of 8.5 × 10−6 cm2 · s−1 was measured for water‐saturated aggregates. The radii of anaerobic centers within several aggregates, measured directly with the electrode, correlated with those calculated from a model of radial diffusion using measured respiration rates and the intra‐aggregate O2 diffusion coefficient. Anaerobic centers were present in all aggregates that denitrified, but not all aggregates with anaerobic zones denitrified. The denitrification rate did not correlate with the size of the anaerobic zone, indicating that factors other than anaerobic volume contributed to the observed rates.
Manganese Nutrition of Flax as Affected by FeEDDHA and Soil Air Drying
Authors: Moraghan J. T. 
Published: July 2010

AbstractFlax (Linum usitatissimum L.) accumulates large quantities of Mn, the uptake of which is reduced by a soil application of FeEDDHA, and develops Mn toxicity symptoms when grown on certain air‐dried, calcareous soils. Since soil Mn solubility is known to be enhanced by air drying, the influence of soil air drying on the abnormality was studied. Soil from the 0‐to 15‐cm depth of a Glyndon loam, a Calciaquoll, was collected from the field. After mixing for uniformity, half of the soil was air dried for 48 h while the other half was stored at 5°C (for 7 d) until required. The DTPA‐extractable Mn levels at planting in the air‐dried and non‐air‐dried soils were 4.2 and 1.9 µg g−1, respectively. Iron treatments of 0 and 2 µg FeEDDHA‐Fe g−1 were imposed on each soil condition. Flax grown on both soils without FeEDDHA developed symptoms of Mn toxicity, but the abnormality was more severe in plants grown on the air‐dried soil. Older leaves of flax contained 1758 and 1014 µg Mn g−1, respectively, when grown on the air‐dried and non‐air‐dried soils; FeEDDHA application reduced the above levels to 68 and 42 µg g−1, respectively, and eliminated all Mn toxicity symptoms. However, younger leaves became severely chlorotic when flax was grown on the FeEDDHA‐treated, non‐air‐dried soil. This FeEDDHA‐induced chlorosis was eliminated by foliar applications of MnSO4, so it was concluded that FeEDDHA had induced a Mn deficiency in flax.
Soil Test Phosphorus as a Regionalized Variable in Leveled Land
Authors: Knighton R. E. , James D. W. 
Published: July 2010

AbstractChanges in spatial variability of soil test phosphorus (STP) after land leveling was studied using regionalized variable theory. Measurements were made on a regular grid and more intensive samples were taken between randomly selected grid nodes. Semivariograms showed anisotrophy and drift in the spatial structure of the data. The range of spatial structure was 25 m after leveling. Kriging was used to map STP and its associated error. Kriging was a better estimator than a fifth order bivariate polynomial. Soil test phosphorus was lognormally distributed and there were no significant differences between sample means before and after leveling. There was no significant correlation between depth of cut, fill and STP.
Mineralogical Variability within Clayey Soil Control Sections and Family Mineralogy Placement
Authors: Karathanasis A. D. 
Published: July 2010

AbstractMineralogical characterizations of 27 Alfisols and Ultisols indicated considerable variability among horizons comprising the control section. Coefficients of variation (CV) for dominant soil minerals critical for family mineralogy placement ranged from 5 to 173% within the same control section. Mineralogical variability within control sections caused 18 of the 27 pedons studied to be placed in incorrect mineralogy classes when mineralogical characterization data from the upper horizon of the control section were used. Using only upper control section mineralogy data, a policy favored by several characterization laboratories for time conservation, 11 pedons were misclassified as mixed instead of montmorillonitic, two mixed vs. illitic, two illitic vs. mixed, two montmorillonitic vs. illitic and one mixed vs. kaolinitic. A composite soil sampling technique utilizing preweighted subsamples from all control section horizons, constituting the upper 50 cm of the argillic according to their thickness, appears to satisfactorily predict the proper family mineralogy classification of soils lacking contrasting layers without increasing characterization time.
Preparation, X‐Ray Diffraction Pattern, and Solubility Product of Manganese(III) Phosphate Hydrate
Authors: Boyle F. W. , Lindsay W. L. 
Published: July 2010

AbstractNo characterization of MnPO4·1.5H2O (manganese [III] phosphate hydrate), other than x‐ray diffraction patterns, has been reported even though this compound has been recognized as a reaction product of manganese‐ and phosphorus‐containing solutions. Evaluation of the chemical and physical properties of MnPO4·1.5H2O is necessary prior to the study of this solid as a possible reaction product in soils. This mineral was prepared by reacting H3PO4 (orthophosphoric acid) with each of the following: MnCO3(c) (manganese [II] carbonate), MnOOH(c) (manganese [III] hydroxyoxide), and MnO(c) (manganese[II] monoxide). The reaction pathways were found to involve O2(g) as the electron acceptor. An intermediate compound, MnOOH(c), was isolated during the reaction by filtering the suspension following the cessation of CO2(g) evolution. X‐ray diffraction patterns were obtained and were matched with previously reported patterns. The refractive index was found to be approximately 1.73. The density was measured pycnometrically and was determined as being 2.5703 ± 0.0014 Mg m−3. The equilibrium constant (K°) for the following reaction: MnPO4·1.5H2O(c) = Mn2+ + PO3−4 + 1.5H2O was found to be 10−34.82 with σ = 0.46.
Oxidation of Iron in Biotite by Different Oxidizing Solutions at Room Temperature
Authors: Amonette J. , Ismail F. T. , Scott A. D. 
Published: July 2010

AbstractBiotite samples (10–20 µm lepidomelane) were mixed with solutions that contained various oxidants (O2, NaOCl, H2O2, or Br2) and salts (NaCl, KCl, NaCl‐NaBPh4, or none) to compare the effectiveness with which these solutions oxidize structural Fe2+ at 25°C when customary procedures and mica samples at different stages of expansion are used. In general, the treatments that minimized interlayer K exchange did not oxidize detectable amounts of Fe2+, whereas those causing mica expansion oxidized equivalent fractions of the Fe2+ if they were given enough time. The rates of Fe2+ oxidation by the O2 and NaOCl‐O2 solutions were very slow in even the expanded mica and were similar enough to suggest the OCl‐ ions did not contribute to the process under these conditions. The Br2 and H2O2 treatments, on the other hand, oxidized 97 and 85% of the structural Fe2+ in a fully expanded mica, respectively, in a 24‐h period. The relative effects of Br2 and H2O2 solutions probably reflect differences in the oxidants themselves but are confounded by the low pH of the Br2 solution, NaBPh4 interactions and H2O2 decomposition. Indeed, all the results make it clear that more distinction needs to be made between the role of the oxidants and the side efects of the solutions and procedures that are used in oxidation experiments.
Spatial and Spectral Relationships of Soil Properties and Microtopography: I. Density and Thickness of A Horizon
Authors: Kachanoski R. G. , Rolston D. E. , de Jong E. 
Published: July 2010

AbstractThe effects of microtopography and an intertill stratigraphic sandgravel layer on the spatial variability of A horizon thickness, density, and mass are examined using standard, spatial, and spectral statistical methods. Soil cores (76 mm diam) were taken every 1 m in a 46 m long transect, in a native soil which is a mixture of Typic Haploborolls and Typic Argiborolls. The parent material is glacial till divided into two formations. The uppermost till is 1 to 2 m thick and is underlain by an intertill seed‐gravel layer of variable thickness. Microtopography parameters were estimated by fitting a least squares quadratic surface to elevation measurements around each soil core. Spectral estimates (coherency, cospectrum, phase spectrum) are calculated using smoothed Fourier methods. Standard correlation indicated a significant relationship between surface curvature in the direction of maximum surface gradient and A horizon thickness and mass; however, only 14% of the variability was explained. Thickness and mass of the A horizon had significant autocorrelation and spectral peaks indicating spatial cycling. The power spectra of A horizon thickness and mass were very similar to that of surface curvature. Coherency and cospectrums indicated that relationships between variables are complicated by phase shifts and opposite correlations in different frequency ranges. This was attributed to lateral water movement in surface depressions and the presence of both open and closed depressions. A horizon properties were not significantly related to the depth to the intertill sand‐gravel layer.