bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long‐term Effects of Mesquite Removal on Soil Characteristics: II. Nutrient Availability
Authors: Klemmedson J. O. , Tiedemann A. R. 
Published: July 2010

AbstractPreviously we reported differences in nutrient availability of desert grassland soils under mesquite [Prosopis juliflora (Schwartz) DC] trees and adjacent open areas. In a related study conducted at that same time (1967), several mesquite trees were removed to measure shading effects. Since then about half of the harvested trees have sprouted and regrown. Now after 13 yr, we report the long‐term effects of mesquite removal on nutrient availability of these soils. In a greenhouse pot test, dry weight yield of shoots plus roots of Arizona cottontop [Digitaria californica (Benth.) Chase] and barley (Hordeum vulgare L. var. gustoe) was used to measure availability of nutrients. Variables in the pot test were mesquite history (mesquite intact, mesquite removed‐sprouted, mesquite removed), location (canopy, open), and nutrients (N, P, S, K). In the analysis of variance, the main effects and all interactions were significant. Yield responses confirmed results of our earlier study that nutrient availability of mesquite canopy soils was significantly greater than that of adjacent open areas. Removal of mesquite resulted in a significant decline in nutrient availability. For sites where mesquite had been removed but then sprouted and regrew, nutrient availability of soils was intermediate between that of mesquite‐intact and mesquite‐removed sites. Removal of mesquite resulted in a large decline in available soil N; smaller losses of available P, K, and S were noted.
Solubility of Aluminum Fluoride, Fluorite, and Fluorophlogopite Minerals in Soils
Authors: Elrashidi M. A. , Lindsay W. L. 
Published: July 2010

AbstractThe solubilities of AlF3(c), CaF2 (fluorite), and KMg3AlSi3O10F2 (fluorophlogopite) were investigated. Equilibrium was approached from both undersaturated and supersaturated conditions. The average equilibrium constant (K°) determined was 10−17.37 for AlF3(c), 10−10.3 for CaF2, and 107.94 for KMg3AlSi3O10F2. Nine soil samples each of strongly acid, slightly acid, and alkaline soils were used for AlF3(c), CaF2, and KMg3AlSi3O10F2 studies, respectively. The 1:5 soil/water suspensions, with and without added mineral, were shaken for 150 d. The F‐ solubility for strongly acid and near neutral soils without added minerals was undersaturated with respect to AlF3(c) and CaF2, respectively. The F‐ solubility for alkaline soils was close to that of KMg3AlSi3O10F2.
A Rapid Routine Method for Obtaining Soil Solution Using Vacuum Displacement
Authors: Wolt Jeff , Graveel John G. 
Published: July 2010

AbstractVacuum displacement, a modification of traditional column displacement utilizing 75‐g soil samples and a mechanical vacuum extractor, was compared to centrifugation as a method for obtaining unaltered soil solution for comprehensive analysis. Soil solutions were displaced by the two procedures from field‐moist Lily (Typic Hapludults), Memphis (Typic Paleudalfs), and Etowah (Typic Paleudults) soil samples having varied chemical and physical properties. Solutions obtained were analyzed for volume of solution recovered, pH, EC, Ca, Mg, Mn, K, Na, NH4, Cl, NO3, SO4, P, and percent ion difference. Vacuum displacement was more efficient than centrifugation in terms of man‐hour requirements and sample turn‐around time. Smaller volumes of soil solution (usually <5 mL) were obtained by vacuum displacement compared to centrifugation, necessitating analytical techniques adapted to uL‐volumes of solution. For the most part, both methods resulted in analate concentrations with coefficients of variation <5% and ion differences <12%. Exceptions were NH4, K, and Na, which were sometimes present at concentrations approaching the limits of detection for the procedures employed. Although significant differences in analate concentrations between the two methods were observed, few of the measured differences would lead to interpretive difficulties for the solution components and soils considered.
Genesis and Classification of Some Paleborolls and Cryoboralfs in Northern Utah
Authors: Jalalian Ahmad , Southard A. R. 
Published: July 2010

AbstractThree soil series in northern Utah were studied to determine if the apparent surface mantle is a depositional discontinuity. Field descriptions show a dark gray silty deposit overlying thick E horizons and reddish brown, clayey skeletal B horizons. Laboratory results show an abrupt change in texture and mineralogy with amphiboles and Ca‐feldspar and zeolites in the surface deposit or upper sequum and quartz, chlorite, mica, and kaolinite in the lower sequum. The fine clay in the upper sequum of all three soils is dominated by amorphous material suggesting an early stage of weathering. Results of these studies suggest that the older soils (lower sequum) were Alfisols. Recent additions of eolian material from Lake Bonneville sediments and Snake River plain have covered the Alfisols and mollic epipedons have developed in the eolian material. These soils are now classified as Paleborolls. We suggest that Thapto extragrade classification would help identify more of the characteristics of these soils than the present classification.
Modeling Corn Grain Yield in Relation to Soil Erosion Using a Water Budget Approach
Authors: Timlin D. J. , Bryant R. B. , Snyder V. A. , Wagenet R. J. 
Published: July 2010

AbstractThe effect of long‐term soil loss on corn (Zea mays L.) grain yields in shallow soils of the Northeast is evaluated using a simple computer simulation model. Easily obtainable soil and meteorological data are used as input. The model relates the change in soil productivity to the reduction of available water holding capacity caused by long‐term soil loss by erosion. Depth to an impermeable layer, which limits the total available water in the soil profile, is considered a nonrenewable soil property. Renewable soil properties such as surface soil structure and fertility, which can be maintained through optimum management, are not considered to limit yields. The model is based on the established relationship between relative yields and the relative transpiration ratio. A simple water budget estimates actual transpiration on a daily basis and calculates stress as a function of relative transpiration ratio. Yields are predicted from total seasonal stress and accumulated heat units. The model has been run using 16 yr of meteorological data to simulate varying climatic conditions, and correlations between actual and predicted yields on deep to moderately deep soils are good. Soil erosion is simulated by removing increments of soil depth. For each soil depth, the model predicts both mean yield and variance. Mean yield values are used to generate productivity curves that graphically depict the relationship between soil productivity and soil erosion. For medium textured soils in New York State, the model predicts that soil erosion will decrease mean yield and increase variability in annual yields when the depth to a root restricting horizon is <70 cm.
A Stochastic Approach to the Crop Yield‐Irrigation Relationships in Heterogeneous Soils: I. Analysis of the Field Spatial Variability
Authors: Russo David 
Published: July 2010

AbstractWhen a deterministic irrigation regime is applied to a heterogeneous field, soil‐water content, soil salinity, and crop yield will vary in space because of the inherent spatial variability in the soil properties. It is important, therefore, to analyze their spatial distributions in the field in order to suggest improved irrigation management schemes for spatially‐variable fields. A stochastic approach was used to analyze the spatial variability of four parameters of the soil‐water retention curve as well as that of the initial soil‐water content and soil salinity, using actual measured field data. These properties were used as inputs for a simplified crop yield‐soil‐water model which, in turn, was coupled with the conditional simulation method to analyze the spatial distribution of the calculated soil‐water content (θ), soil salinity (C), and relative crop yield (Y) in an irrigated field, for various combinations of irrigation water quantity and quality (salinity). Analysis of the results showed that both irrigation water quantity and quality affected the spatial variability in θ, C, and Y but essentially did not affect the spatial dependence of these properties. Although the average (spatial) response of the field was similar to that of a fictitious equivalent homogeneous field, the response of different sites in the field was quite different. For some combinations of irrigation water amount and salinity, the relative difference between relative crop yield obtained at different sites in the field exceeded 100%.
A Stochastic Approach to the Crop Yield‐Irrigation Relationships in Heterogeneous Soils: II. Application to Irrigation Management
Authors: Russo David 
Published: July 2010

AbstractIn a heterogeneous field in which the soil properties vary, under a deterministic irrigation regime, the crop yield might also differ from place to place in the field. These differences may, in turn, reduce the average (over the field) yield relative to that which would be obtained if the soil properties were uniform throughout the field. The simplified crop yield‐soil response model coupled with the conditional simulation method, presented in part I of this study, was used here to evaluate the spatial distribution of the amount of irrigation water required to maintain a prespecified relative crop yield, uniform throughout the field, for a given irrigation water salinity. By considering the water irrigation amounts at different sites in the field, rather than that of the entire field, it was shown that the amount of irrigation water required to obtain a given relative crop yield (for a given irrigation water salinity) can be reduced by 7 to 34%. The amount of water that could be saved increased as the level of the required crop yield increased and as the salinity of the irrigation water decreased. The spatial distributions of the amount of irrigation water required to maintain a given relative crop yield were combined with economic considerations in order to evaluate the spatial distribution of the optimal amounts of irrigation water for a given irrigation water salinity. It was shown that the optimal amounts of irrigation water can be reduced by 6 to 29%, when the responses of different sites in the field is considered rather than the average response of the entire field. Irrigation schemes based on imposition of engineering requirements on the spatial distributions of the optimal irrigation water amounts, increased the net benefit (price of the crop yield minus cost of the irrigation water) by 5.5 to 42% relative to that obtained under deterministic conventional water application schemes. The differences between the two schemes decreased as the irrigation water salinity increased.
Factors Affecting Anion Movement and Retention in Four Forest Soils
Authors: Johnson Dale W. , Cole Dale W. , Van Miegroet Helga , Horng F. W. 
Published: July 2010

AbstractThree hypotheses concerning the movement and retention of anions in forest soils were tested in a series of laboratory and field studies on two Tennessee Ultisols with mixed deciduous forest cover and two Washington Inceptisols, one with deciduous (red alder Alnus rubra Bong.) and one with coniferous [Douglas‐fir, Pseudotsuga menziesii (Mirb.) Franco] forest cover. The first hypothesis, that sulfate and phosphate retention was related to adsorption to free Fe and Al oxides, which were in turn related to soil parent material and degree of weathering, was not supported by results of laboratory and field studies. The young, relatively unweathered Washington Inceptisols adsorbed more phosphate and sulfate than the older, highly weathered Tennessee Ultisols, apparently because of greater amorphous (oxalate‐extractable) Fe and Al in the former. The second hypothesis, that NO‐3 retention was governed primarily by biological uptake, was supported. Nitrate adsorption by soils in laboratory column studies was negligible, but subsequent field studies showed that tree uptake in field plots greatly reduced the leaching of applied NO‐3 in all but the N‐rich red alder plot. The third hypothesis, that inputs of mobile anions will reduce pH and concentrations of bicarbonate and adsorbing anions (e.g., sulfate), were supported by application of chloride as both acid and Na and Ca salts to soil columns in the laboratory. Sulfate concentration as well as bicarbonate concentrations in soil solutions were sensitive to solution pH.
Solid‐State Decomposition Kinetics of Phenyl Phosphorodiamidate
Authors: Gautney J. , Barnard A. R. , Penney D. B. , Kim Y. K. 
Published: July 2010

AbstractKinetic studies were conducted to determine the effect of temperature, phenyl phosphorodiamidate (PPDA) production impurities, and relative humidity on the solid‐state decomposition of the urease inhibitor, PPDA, alone and in urea‐PPDA mixtures (960 g kg−1 of urea and 40 g kg−1 of PPDA). In general, the solid‐state decomposition of pure PPDA obeys first‐order reaction kinetics, whereas the decomposition of the urea‐PPDA mixtures obeys zero‐order kinetics. Rate constants (d−1) for pure PPDA ranged from 0.05 at 70°C to 4.78 at 100°C. Rate constants (decomposition d−1) for urea‐PPDA mixtures ranged from 7.26% at 50°C to 1200% at 90°C. The activation energy (kJ mol−1) is 164 for pure PPDA and 127 for urea‐PPDA mixtures. The presence of production impurities, ammonium chloride (NH4Cl) and diphenyl phosphoramidate (C6H5O)2·PO·NH2, increased the decomposition rate for pure PPDA, but did not significantly affect the decomposition of the urea‐PPDA mixtures. Increasing relative humidity dramatically increased the decomposition rate for PPDA. These results suggest that researchers should minimize the time between preparation and testing of urea‐PPDA mixtures, because at room temperature over half of the PPDA can be lost in 1 yr.
Problems with the Sandy Loam Subclass Definition
Authors: Mays M. D. , Brasher B. R. 
Published: July 2010

AbstractThere are undefined particle‐size distributions that are within the definition of sandy loams but not within the definitions of any of the subclasses of sandy loams according to the 1981 draft of chapter 4 of the Soil Survey Manual. These undefined particle‐size distributions can be accommodated by appending the following phrase to the sandy loam subclass definition: “or less than 15 percent very coarse, coarse and medium sand and less than 30 percent either fine or very fine sand.”
Mononuclear and Polynuclear Aluminum Speciation through Differential Kinetic Reactions with Ferron
Authors: Jardine P. M. , Zelazny L. W. 
Published: July 2010

AbstractThe kinetic reaction of ferron (8‐hydroxy‐7‐iodo‐5‐quinoline‐sulfonic acid) with partially neutralized Al solutions of varying basicity and age were investigated with the intent of separating mononuclear and polynuclear Al. Ferron solutions buffered with varying quantities of NaOAc, NH2OH·HCl, and acetic acid suggested that reduction of ferron by NH2OH·HCl may be essential before monotonically increasing absorbance vs. time functions occur for Al reactions with ferron. When ferron is buffered with appropriate quantities of NaOAc and NH2OH·HCl it must be aged for ⋍5 d at room temperature until reduction has slowed. This solution remains stable for ⋍25 d and exhibits consistent kinetic reactions with Al during this time period. A large portion of ferron interactions with partially neutralized Al of varying basicity and age were described by a binary species first‐order rate function, which provided the rates of monomer and small polymer reactions with ferron as well as the mole fraction of monomeric species present (fa). Modelfitted fa are based on the differential kinetic reactions of ferron with Al, thus arbitrary separation times for determining mononuclear and polynuclear Al are avoided. Rate parameters established for mononuclear Al solutions using a single species first‐order equation compared well with those determined for mononuclear Al from partially neutralized solutions using the binary species model. Ferron reactions at longer times were related to the decomposition of large Al polymers, which were welldescribed by pseudo first‐order kinetics.
Determination of Inorganic Mononuclear Aluminum by Selected Chelation Using Crown Ethers
Authors: Evans Andrew , Zelazny Lucian W. 
Published: July 2010

AbstractThis study was conducted to determine whether cation‐selective crown ethers could be utilized to measure inorganic mononuclear Al3+ in solutions containing Al‐complexing ligands. The dibenzo‐18‐crown‐6 ether was found to selectively chelate inorganic mononuclear Al3+ in the presence of common soil cations (Na, K, Ca, Mg, Fe, and Si). Aluminum previously complexed with di‐NaEDTA, oxalic, and citric acid was not chelated by the crown ether. The presence of high concentrations of F‐, SO2‐4, and NO‐3 in the sample solutions did not influence the determination of inorganic mononuclear Al3+. Determination of inorganic mononuclear Al3+ was reproducible to within ±0.17 × 10−6 mol L−1 in the 0.8 to 10 × 10−6 mol Al L−1 concentration range.
Quantitative Evaluation of Pedogenic Changes in Boralfs (Gray Luvisols) of East Central Saskatchewan
Authors: Santos M. C. D. , St. Arnaud R. J. , Anderson D. W. 
Published: July 2010

AbstractZirconium oxide/quartz ratios for the soil horizons of three Boralfs (Gray Luvisols) indicated that two of the soils were developed from sufficiently uniform deposits to permit quantitative evaluations of changes resulting from soil formation. A “pedogenic index” based upon total quartz content of horizons allowed the expression, as a percentage, of soil constituents present in relation to original contents in either total horizons or in component soil separates within them. The index, based upon the total quartz content of each horizon, provides values that overcome errors resulting from changes in particle size distribution of quartz such as occurs in Boralfs or other soils where significant physical breakdown of coarse to finer fractions has occurred. The index shows that approximately one‐third of the original sand in the E horizons has been physically weathered to finer sizes, dominantly to coarse silt size, but also down to clay size. Elemental analyses indicate that the Na‐ and K‐bearing minerals are more resistant than the Ca‐ and Mg‐bearing minerals, and that weathering has occurred in all size fractions. As a consequence, Ca and Mg, and to a lesser extent, Na and K, undergo greater net losses from the solum than do Si, Al, and Fe. Redistribution of the latter three elements within the sola is directly associated with the translocation of clay. Physical breakdown and lessivage are the major processes in all three soils, but chemical weathering and leaching losses are also important. Preferential translocation of fine clay (<0.2 µm) and the weathering of coarse clay (2‐0.2 µm) to fine clay size in both E and Bt horizons is substantiated.
Reclamation of an Ultisol Damaged by Mechanical Land Clearing
Authors: Alegre J. C. , Cassel D. K. , Bandy D. E. 
Published: July 2010

AbstractMechanical land clearing in 1972 of a Yurimaguas soil (fine‐loamy siliceous, isohyperthermic Typic Paleudult) located in the Amazon Basin of Peru resulted in compacted soil that was abandoned for continuous crop production in 1974. The purposes of this study were to reclaim this abandoned land for continuous cultivation and to evaluate temporal changes in soil physical properties with time after reclamation treatments began. In February 1980, guinea grass [Panicum maximum L.], which covered the compacted soil, was cut by hand, dried, and burned. The following eight reclamation treatments were imposed: (1) control (no till), planted with a planting stick; (2) rototill (12 kW) and stick planted; (3) rototill (48 kW); (4) chisel plow 25‐cm deep, rototill (48 kW); (5) controlled traffic (i.e., assignment of pathways for foot traffic); (6) bedding with hoe and planted with stick; (7) simulated subsoiling to 25 cm with a tile spade; and (8) mulching (mulch applied when seedlings were 10‐ to 25‐cm high). The following soil physical properties were quantitied several times during the study: infiltration rate, cone index (CI), bulk density (ρb), and the soil‐water characteristic. The crop rotation during the 2‐yr‐long period was rice (Oryza sativa L.)‐soybean [Glycine max (L.) Merr.]‐corn (Zea mays L.)‐soybean‐corn‐rice. Compared to the control treatment, all others decreased ρb and CI and increased infiltration rate, macro porosity, and total porosity in the 0‐ to 15‐cm depth. Only chisel plowing and simulated subsoiling alleviated the detrimental effects of the compacted soil below 15 cm. Infiltration rate at the conclusion of the experiment for the control treatment was 9 mm h−1 compared to 148 mm h−1 for the chisel plow treatment. Yield responses were greater for chiseling and simulated subsoiling. For example, the average relative grain yield for each of the three crops was 100% for chiseling; for no‐till, relative yields were 69, 23, and 20% for rice, soybean, and corn, respectively. We conclude that compacted soils similar to the Yurimaguas series can be reclaimed for continuous cropping by using deep tillage practices such as chisel plowing and subsoiling.
Vertical Root Distribution and Strontium Uptake of a Slash Pine Stand on a Florida Spodosol
Authors: Van Rees K. C. J. , Comerford N. B. 
Published: July 2010

AbstractRoot length distribution of slash pine (Pinus elliottii Engelm. var. elliottii) and associated understory vegetation was investigated for an Ultic Haplaquod in north‐central Florida. One‐third of the length of pine roots (<1 mm in diameter) was present in the argillic horizon below the 1 m depth. Slash pine taproots extended between 200 and 330 cm below the surface, (i.e., 1‐2.3 m into the argillic horizon). Slash pine roots were often found growing in large diameter, dead palmetto roots. Two‐thirds of the soil samples taken from the E horizon had all the pine roots growing in dead palmetto roots. Stable strontium (Sr) was placed in the argillic horizon and in the litter layer. Strontium concentration in the slash pine foliage increased 30 to 50% (depending on the age of the foliage sampled) when the argillic horizon was treated. There was no apparent Sr increase in needle tissue from spiking the litter layer. This effect was most likely due to the competition from associated vegetation.
Sweetgum Seedling Growth and Vesicular‐arbuscular Mycorrhizal Development as Affected by Soil Fumigation
Authors: Snyder C. S. , Davey C. B. 
Published: July 2010

AbstractThe effects of soil fumigation with methyl bromide (390 kg/ha) on sweetgum (Liquidambar styraciflua L.) seedling height, root collar diameter, root morphology, vesicular‐arbuscular mycorrhizal (VAM) infection, soil‐borne spore number, and soil fertility were monitored from seeding in the nursery until lifting. Seedlings in nonfumigated soil had greater heights, root collar diameters, and VAM infection than seedlings grown in fumigated soil. Differences between fumigation treatments were statistically significant for root collar diameter and VAM infection between 92 and 131 d after seeding, and for VAM infection after 320 d (lifting). Soil‐borne spore number increased markedly between 92 and 176 d after seeding but no significant difference between soil fumigation treatments was detected. Soil fertility was not significantly affected by soil fumigation. At lifting, seedlings were graded into large (≥7.6 mm) and small (≤6.9 mm) root collar diameter classes within each soil fumigation treatment and outplanted. Height and diameter growth differences between seedlings lifted from fumigated or nonfumigated soil were not significant after one growing season in the field. However, root collar diameter of seedlings from nonfumigated nursery soil was larger than that of seedlings from fumigated nursery soil after one growing season. Glomus fasciculatum (Thaxt. sensu Gerd.) Gerdemann and Trappe was indigenous to both the nursery and outplanting site.