bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soils Developed in Sediments from Late Quaternary Water Bodies in Northern New York
Authors: Kern J. S. , Bryant R. B. 
Published: July 2010

AbstractExtensive areas of soils in northern New York have formed in parent materials deposited in late Quaternary water bodies. In previous studies, distinctions among these lacustrine, marine, and brackish‐water deposits have relied on the identification of fossils and continuous shoreline features; however, evidence of this kind is not always present. The morphology, mineralogy, and chemistry of a number of soils were characterized to determine whether differences in soil properties were attributable to the depositional environment and if soil characterization data are useful criteria for differentiating among soils developed in these deposits. X‐ray diffraction was used to characterize clay‐sized components. Standard soil characterization procedures were used to characterize soil chemical and physical properties. Soils formed in marine and lacustrine sediments were found to have similar mineralogies, dominated by vermiculite, illite, kaolinite, and interestratified clay minerals with lesser amounts of smectite, chlorite, and clay‐sized quartz, feldspars, and amphiboles. Chemical differences between soils formed in lacustrine and marine sediments do reflect the chemistry of the depositional environments, and soil characterization data are useful for distinguishing among soils developed in these parent materials. The data support a westward influence of the Champlain Sea beyond where marine fossils have been found to date. The area appears to be contiguous with, and transitional to, freshwater drainage from the Ontario Basin. The data also support the presence of a brackish‐water phase in the St. Lawrence Valley, and a water plane for this late Champlain Sea phase is postulated.
Extraction and Determination of Sulfur in Organic Horizons of Forest Soils
Authors: Maynard D. G. , Kalra Y. P. , Radford F. G. 
Published: July 2010

AbstractLittle information exists on the accuracy, precision, and make‐up of extractable S in surface organic horizons of forest soils. Eight extractants (H2O, 0.01 M CaCl2, 0.01 M KCl, 0.01 M LiCl, 0.003 M NH4OAc, 0.003 and 0.01 M NH4Cl, and 500 mg P L−1 as Ca(H2PO4)2·H2O) were evaluated for the extraction and determination of SO4‐S and total extractable S in surface organic horizons of five forest soils. The analyses for SO4‐S and total extractable S were performed by ion chromatography (IC) and inductively coupled plasma atomic emission spectrometry (ICP‐AES), respectively. Each of the weak salt extractants removed similar amounts of SO4‐S and total extractable S. Water was the least desirable extractant because it removed more organic S than the salt extractants, was the most variable for IC analysis, and produced inconsistent results. The 0.01 M NH4Cl extractant, however, was found to be the most consistent extractant. The precision ranged from 3.7 to 8.9% for the IC analyses excluding the aspen (Populus tremuloides Michx.) sample and from 1.9 to 8.4% for the ICP‐AES analyses. Poor precision in the SO4‐S determination of the aspen organic horizon was due to the elution of an unidentified peak adjacent to the S peak. Quantitative recoveries from 102 to 108% and from 97 to 108% were obtained in the 0.01 M NH4Cl extract by the IC and ICP‐AES methods, respectively. The effect of varying solution to soil ratios was also determined for 0.01 M NH4Cl. The 10:1 solution to soil ratio was the most consistent. Ratios <10:1 had significantly lower concentrations of extractable S and SO4‐S for three soils and caused logistical problems in the laboratory (i.e., slower filtering, more sample required) because of the low solutin‐to‐soil ratio. Storage of airdried material at room temperature (20 ± 4 °C) for 1.5 yr resultd in increased total extractable S and SO4‐S concentrations.
Solubilization of Soil Organic Matter by Liquid Anhydrous Ammonia
Authors: Norman R. J. , Kurtz L. T. , Stevenson F. J. 
Published: July 2010

AbstractA laboratory study on the solubilization of organic matter in three soils (Drummer, Typic Haplaquoll; Blount, Aeric Ochraqualf; Cisne, Mollic Albaqualf), by application of liquid anhydrous ammonia (LAA) revealed a six‐ to sevenfold increase in water‐soluble organic C in the center radial zone (0‐1.5 cm radius) around the point of application of 44 kg N ha−1 and a seven‐ to ninefold increase where 206 kg N ha−1 had been applied. Initially, a three‐ to fourfold increase in water‐soluble organic C was measured as far as 3.0 cm from the application point at the 44 kg N ha−1 rate and as far as 6.0 cm at the 206 kg N ha−1 rate. Maximum concentrations of water‐soluble organic C (700 mg C kg−1) decreased with time after LAA applications and with distance from the point of application. When pH levels were above 6.5 to 7.0, water‐soluble organic C was linearly related to both exchangeable NH+4‐N concentration and pH. As the concentration of exchangeable NH+4‐N and soil pH declined with time due to nitrification and its acidifying effects, the concentration of water‐soluble organic C also declined. After periods of 28 to 112 d, depending on application rate and soil properties, amounts of water‐soluble organic C, on a whole soil basis, declined almost to their original levels although elevated concentrations were still present in the center of the application zones. Estimates were not made of losses of solubilized organic C via microbial conversion to CO2. However, since the maximum increases in solubilized organic C were always <1% of the total organic C (calculated on a total surface soil basis), drastic declines in soil organic matter content would appear unlikely as a result of LAA applications to these soils.
Conditions for Al13 Polymer Formation in Partially Neutralized Aluminum Solutions
Authors: Bertsch Paul M. 
Published: July 2010

AbstractThe influence of synthesis methodology on the formation of the Al13([AlO4Al12(OH)24(H2O)12]7+) polymer was investigated to better establish boundary conditions for its formation. The amount of Al13 polymer formed in solutions ranging in Al concentration from 3.34 × 10−4 to 3.34 × 10−2 mol L−1 was found to be highly dependent on OH/Al ratio (ñ), neutralization rate, mixing conditions, and initial Al concentration. For the 3.34 × 10−3 mol Al L−1 solution synthesized at 1.2 cm3 min−1, the Al13 polymer formed only when ñ exceeded 1.5, whereas this polymer predominated in a solution 3.34 × 10−2 mol L−1 with respect to Al at ñ ≥0.4. There was no evidence for Al13 polymer formation in solutions ≤3.34 × 10−4 mol Al L−1 with ñ = 2.5 synthesized at the 1.2 cm3 min−1 base injection rate; however, the formation of this species could be induced in the 3.34 × 10−4 mol Al L−1 solution by increasing the base injection rate to 100 cm3 min−1. Utilizing an Erlenmeyer flask instead of a beaker for the neutralization reaction resulted in different amounts of Al13 formation, and this was believed to result from differential mixing conditions. The data suggest that the formation of the Al13 polymer in partially neutralized Al solutions is an artifact of synthesis conditions requiring inhomogeneous pH conditions at the point of base injection resulting in the formation of the Al(OH)‐4 ion. It would appear that this polymer is of little general significance to secondary Al mineral formation in acidic weathering environments.
Comparison of Two Methods for Quantifying Extraradical Mycelium of Vesicular‐Arbuscular Mycorrhizal Fungi
Authors: Bethlenfalvay Gabor J. , Ames Robert N. 
Published: July 2010

AbstractExtraradical mycelium of Glomus mosseae (Nicol. & Gerd) Gerd. and Trappe, a vesicular‐arbuscular mycorrhizal (VAM) fungus, was assessed by two quantitative methods using subsamples of the same soil. Fungal biomass was determined by a chitin assay and the length of fungal hyphae in the soil was obtained by direct microscopic measurements. Total hyphal length, including hyphae <5 µm in diameter, was not correlated (P > 0.05) with total soil chitin; however, the length of hyphae ≥ 5µm in diameter correlated significantly (P < 0.01) with VAM‐fungal biomass. There is a strong relationship between these methods for the determination of the extraradical VAM‐fungal mycelium. The two methods permit the calculation of a “specific mass' (µg/m) for VAM‐fungal hyphae. Considerations for using either method to quantify extraradical VAM‐fungal mycelium are discussed.
Interference of Humic Substances on Chloride Analysis Using the Chloride Ion‐selective Electrode
Authors: Sikora F. J. , Stevenson F. J. 
Published: July 2010

AbstractHumic substances interfered with the ion‐selective electrode determination of Cl‐ by complexing Ag+ and thereby reducing the activity of the potential determining ion. Binding of Ag+ was proven with a technique that involved equilibrium dialysis and Ag+ determination by atomic absorption spectroscopy. Competition between Ag+ and H+ for binding sites was evident from an increase in millivolt response of the Cl‐ ion‐selective electrode with addition of HNO3 and release of protons upon Ag+ binding in the dialysis experiment. Selectivity coefficients (kCl,HA) for 11 humic and fulvic acids ranged from 0.59 × 10−4 to 1.3 × 10−4 mol g−1 at pH 6.5. Interference is negligible in solutions containing <0.1 g L−1 humic substances, but is serious in samples with low concentrations of Cl‐ (< 10−4.5 M) and high amounts of organic matter (>0.1 g L−1).
Clay Mineralogical and Chemical Properties of Nonallophanic Andepts (Andisols) from Oregon, USA
Authors: Shoji Sadao , Suzuki Yoshinori , Saigusa Masahiko 
Published: July 2010

AbstractWe studied clay mineralogical and chemical properties of Murtip and Quillayute soils from Oregon that are classified as Typic Dystrandepts. The soils are nonallophanic and have clay fractions dominated by chloritized 2:1 minerals. Both showed chemical properties similar to those of most nonallophanic Andisols from Japan and satisfied the criteria for andic soil properties. The strong allic properties of the soils were due to the abundance of chloritized 2:1 mineral and low base saturation.
Weathering Processes of Asbestos‐rich Serpentinitic Sediments
Authors: Schreier H. , Omueti J. A. , Lavkulich L. M. 
Published: July 2010

AbstractAsbestos‐rich serpentinitic sediments weather rapidly in acid environments and in the process trace metals are released and smectite clays are formed in the soils. A study was carried out in the Sumas River Basin in northwestern Washington State, where a landslide has exposed asbestos‐rich serpentinitic rocks. Between 1975 and 1985 the river draining the landslide has flooded several agricultural fields and on several occasions sediments that are rich in chrysotile asbestos were deposited. The analysis of soil samples from the inundated sites revealed that Ni, Cr, Co, Mn, and Mg were very high in the sediments and leached into the lower more acidic soil horizons. Laboratory extraction experiments were carried out in water and organic acid media. Under neutral and alkaline conditions little chemical breakdown was observed, but in the presence of citric and oxalic acid more than 50% of Ni and Cr is removed by artificial weathering at room temperature. At the same time Mg is removed from the asbestos fiber structure as shown by the energy dispersive x‐ray spectroscopy (EDX) analysis.
A Chronotoposequence of Soils Developed in Loess in Central Louisiana
Authors: Schumacher B. A. , Miller B. J. , Day W. J. 
Published: July 2010

AbstractSurface soils developed in Sicily Island loess (thermoluminescence age 75 000–95 000 yr B.P.) and Peoria loess (thermoluminescence and 14C age 9000–22 000 yr B.P.) were sampled to study a chronosequence in the lower Mississippi River valley. A toposequence composed of an Udalf and an Aqualf was sampled in each of the loesses to evaluate relationships between topography and soil formation. Morphological, physical, chemical, and mineralogical properties were examined to determine the influence of time and topography on soil formation. Soils developed in the older Sicily Island loess had thicker argillic horizons and sola, a greater degree of horizonation, and greater maximum and total sola clay contents than younger Peoria loess‐derived pedons. Chemically, soils developed in the older loess had less exchangeable Ca, more exchangeable Al, lower mean effective cation exchange capacity (ECEC) per unit clay for the whole argillic horizon, lower base saturations, and were more acidic than their younger counterparts. Kaolinite and vermiculite were more abundant in the older Sicily Island loess‐derived soils while smectite and mica percentages were higher in Peoria loess‐derived pedons. Topography influenced soil formation through differences in soil drainage conditions. Soils occupying better‐drained sites had thicker sola and argillic horizons, thinner total surface (A + E) horizons, redder hues, and were more acidic with less exchangeable Ca, lower base saturations, and lower mean ECEC per unit clay for the whole argillic horizon than soils forming under poorly drained conditions. Kaolinite and mica were more abundant in the better‐drained soils while smectite was in greater quantities at the poorly drained sites.
Nitrogen Mineralization in a Desert Soil: Interacting Effects of Soil Moisture and Nitrogen Fertilizer
Authors: Fisher F. M. , Parker L. W. , Anderson J. P. , Whitford W. G. 
Published: July 2010

AbstractThe responses of N mineralization to two patterns of supplemental water, N fertilizer, and a drying‐wetting episode were examined in order to evaluate the effects of variation in timing and intensity of natural precipitation on N availability. Field plots received either 6 mm water/week or 25 mm water/month with or without 10 g N m−2. Samples were collected three times from July 1984 to March 1985 and incubated in the lab for 28 d. The effects of drought were simulated by drying soil at 35°C for 28 d followed by 168‐d leaching incubations. Supplemental water reduced 28‐d mineralization by 22% in soils collected during dry and moderate soil moisture conditions (July 1984, October 1984) but had no effect on soils collected during a moist period (March 1985). Nitrogen fertilizer had no effect on 28‐d mineralization in soils from July but increased 28‐d mineralization by 58% in soils from October and March. Air‐drying increased mineralization rates across all field treatments during the first 14 d of the 168‐d leaching incubations. Mineralization rates were lower in soils from watered plots in both the air‐dry and field‐moist treatments. Air‐drying interacted with both the water and N treatments by increasing watering effects and decreasing fertilizer N effects. The observed drying effects appear to be a net result of several processes that, on the whole, tend to increase N availability. Mineralization rates in both experiments were lower in 6 mm/week soils than in 25 mm/month soils which, in turn, were lower than unwatered controls. We hypothesize that increased moisture availability eventually leads to losses of mineralizable N as initially rapid mineralization converts organic N to inorganic forms that are readily lost from the soil.
Use of Sorptivity to Determine Field Soil Hydraulic Properties
Authors: White I. , Perroux K. M. 
Published: July 2010

AbstractConvenient and reliable techniques for estimating intact soil hydraulic properties are required for predictions of soil‐water flow in the environment. The dependence of sorptivity, S, on water supply potential, Ψ0, is used here to find the dependence of the intact field soil hydraulic properties soil‐water diffusivity, D(θ), hydraulic conductivity, K(θ), and soil‐water characteristic Ψ(θ) on water content, θ. The approximations used in deconvoluting sorptivity are examined critically using a simple parametric D(θ) that gives analytic solutions applicable to most known soil behavior. We show that the Parlange approximation differs from the exact solution by <5% over a very wide range of D(θ) and over the entire water content range. A rapidly convergent iterative scheme in which this approximation forms the initial estimate is introduced for situations where greater accuracy is required. The technique is tested for a repacked soil, Ustochrept, and the D(θ) derived from S(Ψ0) agrees excellently with conventional measurements. We use the disc permeameter to find S(Ψ0) at 20 sites for an intact field soil, Haplustalf. The D(θ) derived from these measurements is not strongly θ‐dependent. This is attributed to the shape of Ψ(θ), which, in contrast to repacked samples, shows that as θ approaches saturation, Ψ approaches zero gradually. The capillary length found from the K(Ψ) measurements is only 23 mm. Both findings are attributed to the presence of biopores in the field soil. Sorptivity may be used to determine reliably intact soil hydraulic properties whose magnitudes reflect the intricacies of field soil structure.
Computed Tomographic Analyses of Water Distribution in Three Porous Foam Media
Authors: Brown J. M. , Fonteno W. C. , Cassel D. K. , Johnson G. A. 
Published: July 2010

AbstractComputer Assisted Tomography (CAT) is commonly used in diagnostic radiology to make nondestructive images and analyses of cross sections of the human body. CAT scanning may also be useful in imaging and measuring spatial distribution and changes in water distribution in porous media. The purpose of this paper is to review some of the details of CAT scanning that are of importance to the application of CAT scanning porous media and to evaluate the use of the CAT scanner to measure the spatial distribution of water in three different porous media. The scanner's response to changes in the spatial distribution of water in three different porous phenolic foam materials after draining for 16 h was investigated. Water content distributions were successfully detected with good resolution on the x‐ray image. Comparisons of CAT vs. gravimetrically determined water content indicated a significant linear relationship between the methods. Results from these experiments indicate that the CAT scanner can nondestructively measure volume wetness in phenolic foam media. The clarity of the CAT images suggests that CAT scanning has great potential for studies where small and rapid changes in water content within small volumes of media are desired.
Kriging with Generalized Covariances
Authors: Morkoc F. , Biggar J. W. , Nielsen D. R. , Myers D. E. 
Published: July 2010

AbstractElectrical conductivities (EC) of saturated paste extracts of 225 soil samples collected from depths of 30 to 60 cm along five transects were determined. The field was irrigated using a two‐line source sprinkler system that applied two different qualities of irrigation water. The sampling interval along each transect was 1 m. Forty‐five soil samples were collected from each transect, with each transect separated by 10 m. The mean and four directional experimental variograms of the EC were computed. The east‐west (0°) directional variogram showed a structure with a range of 19 m. The raw data showed a skewed distribution with two outliers. One hundred eleven of the total data points were used to check for the presence of a drift and to determine the best generalized covariance function. The best general drift, calculated with mean squares, was found to be of order one. Structural analysis confirmed that the best drift order was one, and the best generalized covariance fit had linear and cubic terms. The best fit covariance function had a mean square error (MSE) of 0.187 and a correlation coefficient of 0.98 from the jackknifing. The cross‐validation of the best covariance fit was performed by removing each data point and estimating from the remaining data (MSE = 0.164). If the difference between the measured and estimated points was greater than twice the standard deviation, that point was considered to be an outlier. The results of cross‐validation, when 111 data points were used, showed no outliers. The scatter diagram of the estimated values and reduced error showed no correlation (r = −0.0035). On the other hand, a high correlation (r = 0.93) was found between the estimated and the true values. The best covariance function with a drift of order one was used to estimate 225 measured values, as well as an additional 1260 values over the entire field with a grid size of 1 × 1.25 m. This technique allowed detailed information to be obtained from a limited number of data points with dependability.
Monovalent Ion Adsorption by an Oxisol
Authors: Charlet Laurent , Sposito Garrison 
Published: July 2010

AbstractAn experimental method was developed to measure simultaneously the net proton surface charge density (σH) and surface excesses of metal (nM) and ligand (nL) on an Oxisol suspended in a ML electrolyte solution. The soil sample was first saturated with a LiClO4 solution whose pH and ionic strength were equal to the maximum values to be used in the adsorption experiments. The ionic strength then was decreased, LiClO4 was exchanged for ML (ML = NaCl or KNO3), and a soil paste was prepared to allow reproducible sampling of small quantities of the whole soil. A discontinuous titration followed in which the soil paste was equilibrated with a series of ML electrolyte solutions of specific pH and ionic strength. Values of nM and nL were measured at 25°C, and it was shown that the point of zero net charge (PZNC) ≈ 4.2, independent of the electrolyte and its ionic strength in the range 4 to 500 mol m−3. Given a negligible permanent surface charge, typical of Oxisols, PZNC = PZNPC (point of zero net proton charge). The net proton surface charge density then could be calculated from titration data renormalized to the PZNC. The net proton surface charge of the Ha‐plustox used in this study vanished at pH 4.2 and showed very little dependence on ionic strength, indicating the dominant role of kaolinitic and organic matter constituents in determining its surface properties. Surface complexation reactions between the soil and a 1:1 electrolyte solution were characterized quantitatively by intrinsic equilibrium constants calculated according to the triple layer model. The average values found were similar to those that have been obtained previously for specimen hydrous oxides suspended in 1:1 electrolyte solutions.
Selenite Adsorption on Alluvial Soils: I. Soil Composition and pH Effects
Authors: Neal Rosemary H. , Sposito Garrison , Holtzclaw K. M. , Traina S. J. 
Published: July 2010

AbstractThe adsorption of selenite by five alluvial soils from the San Joaquin Valley, California, was investigated with respect to the effects of soil composition and pH. Soil samples were prepared in the form of Na‐saturated pastes. Adsorption experiments were carried out in a 50 mol NaCl m−3 background at initial selenite concentrations comparable with those found in natural soil systems. The samples were equilibrated under N2‐stirring in a constant‐temperature apparatus with pH and redox conditions monitored. Selenite adsorption by the soils decreased uniformly with increasing pH in the range 4 to 9 and was independent of soil series above pH 6.