bluuebunny/crossref_metadata_2025_split huggingface dataset:
Weighing Lysimeters for Long‐Term Water Balance Investigations at Remote Sites
Authors: Kirkham R. R. , Gee G. W. , Jones T. L. 
Published: July 2010

AbstractTwo weighing lysimeters were installed at a remote location on the Dep. of Energy's Hanford Site in Washington State in 1978 and 1979. Platform‐type electronic scales were placed below the soil surface to measure the weight changes of a large (∼7 Mg) container of soil. The load cells of the scales have been exposed to high humidity and to periodic contact with drainage water, but have operated without failure since installation (over 5 years). Weight changes are continuously recorded, with hourly averages transmitted by phone line directly to the laboratory. The sensitivity of the scale is 50 g, equivalent to 0.02 mm of H2O.
A Field Comparison of Null‐Aligned and Mechanistic Soil Heat Flux
Authors: Pikul J. L. , Allmaras R. R. 
Published: July 2010

AbstractSoil heat fluxes using the mechanistic soil heat flux model of Philip and de Vries were compared with those experimentally determined in the field using a null‐alignment method. Comparisons at 20 depths in the top 60 cm of soil during midsummer showed better agreement of theory and measurement for the wet than for the dry Walla Walla silt loam. Average water content in the top 11 cm was 0.22 and 0.12 m3/m3 for the wet and dry plots, respectively, during the 24‐h measurement period. Measured daily soil heat energy at 0.25 cm was 935 and 910 kJ/m2 for the wet and dry plots, respectively. Computed energy totals at this same depth overestimated measured totals 10‐fold. At 11 cm, the approximate seeding depth of wheat, measured daily soil heat energy was 562 and 863 kJ/m2 for the wet and dry treatments, respectively; respective computed energy totals were 616 and 1345 kJ/m2. The greatest disparity between measured and computed heat flux density occurred at shallow depths (<2 cm) during midday. Computed heat flux density in the top 35 cm generally was overestimated by 20 and 35%, as compared to measured fluxes for the wet and dry plots, respectively. Water content changes at depths equivalent to the seedzone (5–11 cm) in the dry plot were predicted within a factor of two by the vapor flux components of the heat flux model. Computed conductive heat fluxes were more seriously overestimated than were the vapor flux components.
An Automated Manometric Method for Quantitative Determination of Calcite and Dolomite
Authors: Evangelou V. P. , Whittig L. D. , Tanji K. K. 
Published: July 2010

AbstractA rapid automated method is described for differentiation and quantitative determination of calcite and dolomite in earth materials. The method is based on differential pseudo‐first‐order kinetic rates of dissolution of the two carbonate species when reacted with excess of 5M HCl. The method employs manometric measurement of acid‐liberated CO2 with a differential pressure transducer coupled to a strip chart recorder. Tested on calcite and dolomite singly and together in geologic materials, the method is highly discriminatory, highly sensitive, and extremely rapid. Theoretical treatments of pseudo‐first‐order kinetic reactions and of manometric measurements associated with the method are reviewed.
Residual Copper(II) Complexes in Purified Soil and Sewage Sludge Fulvic Acids: Electron Spin Resonance Study
Authors: Senesi Nicola , Sposito Garrison 
Published: July 2010

AbstractElectron spin resonance (ESR) spectra were obtained for both frozen (77 K) aqueous solutions and solid samples of purified fulvic acid (FA) extracted from sewage sludge and from soil organic matter. Large scan range (5000 G) ESR spectra indicated the presence of organic free radical species of semiquinone nature and of iron(III) in sites of highly rhombic character. Narrower scan range (2000 G) ESR spectra were characterized by absorptions of the axiaI type near g = 2, which indicated the presence of residual copper(II) in a dx2−y2 groundstate complexed with ligands arranged in a tetragonal environment. The coordination of the copper(Cu) was shown to be of the equatorial type, involving both oxygen‐(O) and nitrogen‐(N) ligand atoms of FA. The main resonances in the spectrum obtained for the frozen solution of the soil FA were consistent with a principal binding site of 4 O atoms, whereas the minor ESR component in the same spectrum was assigned to a binding site involving 3 O‐and 1 N‐ligand atoms. The reverse order of importance was found in the ESR spectrum of the solid sample, indicating that more N‐containing functional groups of the FA were involved in the binding of residual copper when the FA was not dissolved in water. The ESR parameters for the sludge FA samples indicated that the main resonances were consistent with a 3 O‐1 N‐binding site and the minor ones with 4 O‐or 2 O‐and 2 N‐coordinating environments. ESR spectra of the sludge FA run over a very narrow scan range (1000 G) suggested that an intensely structured pattern at g⊥ could be assigned to a superhyperfine coupling of the unpaired Cu electron to two equivalent N ligand nuclei.
Soil Moisture Regimes on Some Rangelands of Southeastern Idaho
Authors: Jensen Mark E. 
Published: July 2010

AbstractSoil temperature and moisture were measured in 1981 and 1982 on 24 rangeland sites of the Caribou National Forest in southeastern Idaho. Those sites have aridic moisture regimes within cryic soil temperature regimes. Soil Taxonomy does not recognize this combination of soil climatic parameters, although they are probably extensive throughout the higher elevation areas of the Intermountain Region. The sagebrush‐grass and mountain brush vegetative types studied have a mean of 44 d in which moisture is held in the soil moisture control section at < 1.5 MPa (15 bars) suction when the soil temperature at the 0.5‐m depth exceeds 5°C, i.e., growing period. A knowledge of the mean growing period on a site provides the range manager an alternative tool for determinations of range readiness. Soil temperature and moisture monitoring facilitates prediction of range readiness dates and may be used to approximate range readiness over a potentially broader area than site‐specific visual assessment of plant phenology allows.
Perceiving and Defining Soils on Disturbed Land
Authors: Indorante S. J. , Jansen I. J. 
Published: July 2010

AbstractThis study outlines and applies a procedure for mapping and classifying soils on surface‐mined land. Soils are mapped by defining soil units and then delineating corresponding bodies as they exist on the landscape. For a given landscape, soil unit concepts are most useful if they facilitate grouping soils that are alike and separating soils that are different. Soil units on the surface‐mined land were defined by considering premine soil and overburden characteristics, method of mining, and method of soil construction. Considering these historical factors provides clues to soil characteristics and geographic patterns of the soils much as applying geomorphic and conventional soil genesis concepts do for natural soils. Four series were mapped on surface‐mined land. The Morristown, Lenzburg, Schuline, and Swanwick series are Typic Udorthents. Particle size class, which included rock fragments, and reaction class of the control section are the main differences among the series. The approach to defining soil units used in this study is an effective method for perceiving order on surface‐mined land so that the soils can be mapped and classified.
Field Estimation of Amorphous Aluminum with 4M Potassium Hydroxide
Authors: Holmgren G. G. S. , Kimble J. M. 
Published: July 2010

AbstractA procedure is described that provides the field scientist with a rapid, quantitative measure of a form of amorphous Al characteristic of Spodosols and Andepts. The proposed procedure is as follows: React 0.2 g of soil for 10 min with 2 mL of 4M KOH. Dilute to 20 mL and neutralize with HCl to a phenolphthalein end point. Add 2 mL of 1M KF and re‐titrate the suspension to the same end point with drop count additions of 0.1M HCl. Studies of the procedures' sensitivity to reagent concentration, soil/solution ratio and time are presented. Evidence is also presented to demonstrate that this method does not extract Al from crystalline clay minerals. KOH extractable Al values compare well with acid ammonium oxalate extractable Al for amounts 20 g kg−1(2%). Above this, ammonium oxalate Al generally exceeds KOH aluminum by an amount equivalent to the silica extracted by ammonium oxalate.
Computerized Scheme for Chemical Classification of Natural Waters and Soil Extracts
Authors: Held P. , Maianu A. 
Published: July 2010

AbstractA classification triangle (similar to the USDA textural one) is often used to define the chemical classes of water based on anionic and/or cationic composition. The method is laborious. A SAS3 program was developed to do the work rapidly and with high precision. The program was designed for anionic composition, and may be used for cations by changing certain variables.
Application of the Potential Concept to Soil Water Equilibrium and Transport
Authors: Corey A. T. , Klute A. 
Published: July 2010

AbstractThis study examines the view that a “total soil water potential” can be defined such that (i) the water component will always move from regions of higher to regions of lower potential, and (ii) that if the total potential is constant at all points, the water component is in equilibrium. Soil science literature is reviewed to discover why such a concept is widely accepted. It is found that many analyses leading to the total potential concept contain shortcomings which have resulted in invalid conclusions. The key shortcoming is a failure to distinguish between components of a potential that apply only to elements of the soil solution and those that apply only to the water component. Concepts from texts dealing with transport processes and thermodynamics are used to show that there is no single potential that is a function of the state of the soil solution only, whose gradient will always indicate the direction of net transport of the water component, or which if constant in all parts of the system will ensure that equilibrium exists.
Simulated Solute Movement in Wastewater‐Ponded Soil
Authors: Mansell R. S. , McKenna P. J. , Hall M. E. 
Published: July 2010

AbstractA finite‐difference numerical model was used to predict sorption and transport of P in a rapid infiltration land system for renovating urban wastewater. The soil was assumed to be water‐saturated and two‐dimensional steady flow was assumed to occur from a 2‐m wide ponded recharge zone toward a subsurface collection drain located at a lateral distance of 3 m. The rectangular area of interest was bounded underneath by an impermeable layer at the 1‐m depth and was limited to a lateral length of 5 m. Phosphorus sorption in the soil was assumed to occur as two consecutive kinetic reactions—rapid physical adsorption followed by slower chemisorption. Transient movement and sorption of P in the soil was predicted with the model for a step‐function increase in P concentration in the applied waste‐water. Results predicted by the model were used to construct plots of concentration isopleths of P in solution and sorbed phases in the soil. Sorption reactions removed P from the flowing solutions in the soil directly beneath the recharge area, resulting in a retardation of the concentration of P appearing in the drainage water. Simulated breakthrough curves for the concentration of a nonreactive solute in the drainage effluent compared well to those obtained with an approximate analytical model from published literature.
Solute Dispersion During Axisymmetric Three‐Dimensional Unsaturated Water Flow
Authors: Clothier B. E. , Elrick D. E. 
Published: July 2010

AbstractAn approximate, analytic solution is presented for the smearing of solute by both convection and dispersion during axisymmetric three‐dimensional constant flux infiltration from a surface point source in unsaturated soil. The steady‐state pattern of axisymmetric streamlines is used to track individual parcels of water as they move away from the surface emitter. A simple analytic expression is developed to describe the time course of the hydrodynamic dispersion of solute about the convected front as it moves along any given streamline. The location of the convected front at any time is predicted from the profile of wetting along that streamline. The plane‐of‐separation concept is used to find the distance travelled by the convected front along the streamline. The invading solution is considered to act as if to effectively piston‐displace the antecedent soil water. Profiles of bromide concentration along three streamline paths were measured during constant‐flux point‐source infiltration experiments in the laboratory with fine sand. These measurements compared favorably with the theoretical predictions.
Evaluation of the Most Probable Number Method for Enumerating Denitrifying Bacteria
Authors: Davidson E. A. , Strand M. K. , Galloway L. F. 
Published: July 2010

AbstractMost probable number (MPN) enumerations of denitrifying bacteria were conducted on an agricultural soil (pH 6.6) and a forest soil (pH 5.6), in both neutral (pH 6.8) and acid (pH 5.6) media. The neutral medium yielded higher enumerations for both soils and, therefore, appears to be optimal, even for denitrifiers present in acid soils. Enzyme activity assays and MPN enumerations of seven soil samples were weakly correlated (r = 0.71; p = 0.07). One soil exhibited a high MPN enumeration, but had no detectable denitrifying enzyme activity. While the enzyme assay indexes denitrification potential of soils under the environmental conditions at the time of sampling, the MPN enumeration indexes the denitrifying capability of the populations inhabiting soils. A population's denitrifying capability is related to its size, but other factors which might also influence MPN enumerations are discussed. Precise incubation time was critical in the MPN procedure. Delays of 2h affected the scoring results. Populations in some of the incubation tubes appeared to be in a dynamic growth phase at the end of the 14‐d incubation period. Inconsistencies in incubation duration could confound comparisons among soils. Despite inherent flaws and disadvantages, the MPN procedure may be appropriate for certain research objectives as an index of a population's denitrifying capacity. Recommendations and cautions are offered.
Thermoluminescence Dating of Loess from Western Iowa
Authors: Norton L. Darrell , Bradford Joe M. 
Published: July 2010

AbstractThis study was conducted to evaluate thermoluminescence as an alternative to radiocarbon dating to determine age of soil materials low in organic carbon from major loess units from western Iowa. Thermoluminescence (TL) ages were determined for Upper Wisconsinan (Peoria), Basal Wisconsinan (“Farmdale”) and Loveland loesses using the fine‐grained technique on the 4 to 11 µm particle size fraction. Corrections were made for soil moisture and cosmic radiation influences. Thermoluminescence dating was effective in separating the three major loess units studied. The dates for Upper Wisconsinan (Peoria) loess were comparable to published radiocarbon dates, ranging between 13 150 to 24 130; however, there was considerable variability in the dates. The Basal Wisconsinan (“Farmdale”) loess gave considerably older ages (45 960–46 720) than reported with radiocarbon dating. Illinoian age Loveland loess yielded a date of 89 200 yr and was somewhat younger than presumed for the Illinoian advance. Thermoluminescence dating appears to be a viable alternative to radiocarbon dating of loess when organic material is not present, but more work is needed to rectify the age discrepancies. Although TL dating does not give dates in stratigraphic or chronological agreement with radiocarbon dating, it does differentiate the loesses studied.
Length and Slope Effects on Runoff from Sodium Dispersed, Compacted Earth Microcatchments
Authors: Evett Steven R. , Dutt Gordon R. 
Published: July 2010

AbstractThe effects of microcatchment slope and length on runoff and erosion rates were studied under 18 rain storms to get information for design of water harvesting systems. Two replicates of a two‐factor experiment, including 1, 5, 10, and 15% slopes and 3‐and 6‐m lengths, were built on a gravelly sandy clay loam (mixed mineralogy) using 11.2 t ha−1 of NaCl mixed into the surface 2 to 5 cm of soil followed by compaction with a 6‐t roller after a heavy rain. Both slope and length had effects on runoff significant at the 0.1% probability level but the effect of rainfall intensity was not significant. The best fit linear model of runoff, Q, (cm) vs. rainfall, P, (cm) was Q = 0.858(P − 0.34) which explained about 98% of the variability in runoff on individual plots for individual storms but which explained no differences in runoff among treatments. A nonlinear model incorporating slope, s, (m/m) and length, x, (m) accounted for about 96% of the variability in average total runoff among treatments. This model, Q = (s0.0453 x−0.183 + 0.183)(P − 0.339), shows that the important differences in runoff among treatments can be explained by slope and length alone for our conditions. Water quality analyses indicated that only a minor salinity problem but slight to moderate permeability problems might be expected. However, no apparent problems have arisen in 12 yr of grape (Vitis vinifera) and fruit tree (Prunis sp.) cultivation in a water harvesting system using our catchment on the same soil.
Diffraction Patterns and Solubility Products of Several Divalent Manganese Phosphate Compounds
Authors: Boyle F. W. , Lindsay W. L. 
Published: July 2010

AbstractFour divalent Mn phosphate compounds were prepared and identified. The compound, Mn3(PO4)2·3H2O slowly transformed to Mn5H2(PO4)4·4H2O, when the solid was left in contact with the mother liquor. Dissociation constants were determined for the following reactions:
urn:x-wiley:03615995:saj2sssaj198503615995004900030046x:equation:saj2sssaj198503615995004900030046x-math-0001 where log K· is the log of the equilibrium constant, (K·). The mineral Mn(H2PO4)2·2H2O (manganese [II] di‐[dihydrogen phosphate] dihydrate) was identified, but its solubility constant was not determined because of high ionic strength corrections. X‐ray diffraction patterns, densities, and refractive indices were determined for the four minerals.
Phosphate Rock Dissolution in Soil: Indications from Plant Growth Studies
Authors: Anderson D. L. , Kussow W. R. , Corey R. B. 
Published: July 2010

AbstractData from three plant growth studies conducted in controlled environments with seven phosphate rocks (PR) and 18 soils demonstrated how and to what degree selected PR and soil characteristics influence rock phosphate release. Rock phosphate release was calculated as the sum of the increase in plant P uptake and soil NaOH‐extractable P in treated soil as compared to untreated soil. The seven PR materials tested were carbonate apatites containing 0.4 to 7.1% CO2−3 substituted in the apatite lattices. Relative agronomic effectiveness of the rocks was directly related to their substituted CO2−3 contents. In a given soil, substituted CO2−3 content accounted for 71 to 84% of the variation in rock P released. For the group of 18 soils, substituted CO2−3 accounted for nearly 49% of the variation in rock phosphate release. Six selected soil characteristics accounted for 54 to 75% of the variation in phosphate release from a given PR. Across a group of four PR materials, no single soil characteristic appeared to have a consistent and predominate influence on phosphate release. Overlapping of soil spheres serving as a sink for dissolution products of adjacent PR particles decreases dissolution rates of individual particles. Within these spheres of influence are contained the elements (i.e., buffer powers, pH, solute concentration gradients, etc.) driving dissolution.
Fertilizer Phosphorus Recovery After Seventeen Years of Dryland Cropping
Authors: Halvorson A. D. , Black A. L. 
Published: July 2010

AbstractInformation on long‐term fertilizer P recovery by grain crops from a single broadcast application in the northern Great Plains is limited. Uptake of P by grain and straw was measured in 10 or 11 crops (1967 or 1968 to 1983) grown on a Williams loam (fine‐loamy, Typic Argiborolls) in a split‐plot, randomized complete block experiment. Fertilizer N, as main plots, was applied each crop year, except two, at rates of 0, 45, and 90 kg N/ha. Concentrated superphosphate P fertilizer (subplots) was applied only once, at study initiation, at rates of 0, 22, 45, 90, and 180 kg P/ha. The first six wheat crops (Triticum aestivum) were grown in a crop‐fallow system and the last four or five crops, including wheat, barley (Hordeum vulgare), and safflower (Carthamus tinctorius L.), in an annual cropping system. Average P uptake in the grain (21 crops) was 6.4, 7.2, 8.0, 9.1, and 10.0 kg P/ha per crop for the 0, 22, 45, 90, and 180 kg P/ha treatments, respectively, over all N levels. Average P uptake in straw (21 crops) was 0.6, 0.7, 0.9, 1.0, and 1.2 kg P/ha per crop for the same respective P rates. Nitrogen fertilization generally decreased P uptake at low P rates (0 and 22 kg P/ha) but increased P uptake at high P rates (90 and 180 kg P/ha). Average P uptake in grain (21 crops) was 7.6, 8.4, and 8.4 kg P/ha per crop for the 0, 45, and 90 kg N/ha treatments, respectively, over all P rates. Fertilizer P recovery in the grain for the 22, 45, 90, and 180 kg P/ha treatments averaged 32, 25, 23, and 13%, respectively, without N fertilization and 45, 38, 37, and 24% with 45 kg N/ha. The results of this study suggest that a one‐time broadcast application of P fertilizer at rates as high as 90 kg P/ha is an efficient way to meet crop needs and utilize P fertilizer resources.
Soil‐plant Diversity Relationships on a Disturbed Site in Northwestern Colorado
Authors: Stark John M. , Redente Edward F. 
Published: July 2010

AbstractA 5‐yr‐old revegetation plot in the Piceance Basin of northwestern Colorado was used to study the relationship between several soil properties and plant species diversity. Soil properties, including coarse fragment content, topography, depth to bedrock, rooting depth, soil volume, fertility, and salt content, were quantified for 108 subplots. Using simple and multiple regression techniques, plant diversity on the subplots was correlated with the various soil properties. A seed mixture composed of introduced grasses and forbs was used most extensively to study diversity‐soil physical property relationships. For these plots, percent large coarse fragments (> 4.76 mm) within the rooting depth had a high positive correlation with the Shannon‐Weiner diversity index. Depth to bedrock, rooting depth, total soil volume, soil volume within the rooting depth, and a topographic index all exhibited negative correlations with the Shannon‐Weiner index. On plots seeded with a native grass‐forb seed mixture, where variation in salt content was greatest, SAR, ESP, and EC had positive correlations with species richness. When all seed mixtures were considered, rate of fertilizer application had a negative correlation with the Shannon‐Weiner index. In every case where a regression was significant, soil properties normally associated with high production resulted in low diversity and soil properties normally associated with low production resulted in high diversity. Mechanisms are proposed to explain the relationships between soil factors and diversity. Management techniques are also suggested which could be incorporated into the reclamation process to increase plant diversity.