bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wood Residue and Fertilizer Amendment on Bentonite Mine Spoils: II. Plant Species Responses
Authors: Smith J. A. , De Puit E. J. , Schuman G. E. 
Published: July 2010

AbstractSecond growing season plant species biomass, composition, and diversity responses to varied wood residue and fertilization treatments on bentonite mine spoils are reported. Two seed mixtures, each with six plant species,, were seeded on four wood residue rates (0, 45, 90, and 135 Mg ha−1) and four N fertilization regimes (0, 2.5, 5.0, and 7.5 kg N Mg−1 of wood residue). Some species were poorly established irrespective of treatment (green needlegrass, Stipa viridula) or became established to a limited extent only under specific residue‐fertilization treatment combinations (slender, crested, and pubescent wheatgrass; Agropyron trachycaulum, A. desertorum, and A. trichophorum, respectively). The remaining species became well established under specific treatment combinations. Western wheatgrass (Agropyron smithii) and Nuttall saltbush (Atriplex nuttallii) responded positively to increasing residue rate, but were unaffected by fertilization. Smooth brome (Bromus inermis), streambank/thickspike (Agropyron riparium/dasystachyum), tall (Agropyron elongatum) and intermediate (Agropyron intermedium) wheatgrass exhibited significant, although varied, interactive responses to residue and fertilization rate. Total plant biomass was responsive to residue rate, but peaked at a lower rate (90 Mg ha−1) for the native than for the introduced (135 Mg ha−1) mixture. Differences in species and growth form composition occurred among treatments. Maximum diversity occurred at residue rates lower than those for maximum productivity; 45 Mg ha−1 and 90 Mg ha−1 for the native and introduced mixtures, respectively. Diversity was consistently stimulated by fertilization for the introduced species mixture, but responded variably to fertilization for the native mixture.
Nitrate Leaching and Drainage from Annual and Perennial Crops in Tile‐drained Plots and Lysimeters
Authors: Bergström Lars 
Published: July 2010

AbstractLeaching of NO3 with drainage water from tile‐drained field plots and from three types of lysimeters was estimated during a 4‐yr period. Treatments included barley (Hordeum distichum L.) with and without N‐fertilizer, a grass ley (Festuca pratensis), and a lucerne ley (Medicago sativa) (i.e., 4‐yr forage crops). The maximum amount of NO3 leached was 36 kg N ha−1 yr−1 for barley fertilized with Ca(NO3)2 (120 kg N ha−1 yr−1). For unfertilized barley the corresponding amount was 5 kg N ha−1 during the same period. The NO3 fluxes from the grass and lucerne leys were mostly below 5 kg N ha−1 yr−1. However, after the grass ley was plowed, considerable leaching occurred, reaching 42 kg N ha−1 during 20 weeks following plowing. Weather conditions had a strong influence on the temporal distribution of leaching losses. Lysimeters, compared with tile‐drained plots, had generally higher drainage volumes. The slow dynamics of groundwater beneath the drainage‐tiles can explain most of this difference. Lysimeters with disturbed soil profiles usually had higher drainage volumes than lysimeters with undisturbed profiles. Despite these differences, all methods consistently estimated the relative differences between the cropping systems concerning leaching of NO3. The degree of variation in drainage flow between lysimeter replicates was also satisfactorily low.
Mineralization Potential for Phenol in Subsurface Soils
Authors: Dobbins Durell C. , Thornton‐Manning Janice R. , Jones Daniel D. , Federle Thomas W. 
Published: July 2010

AbstractThe mineralization of 14C‐phenol to 14CO2 was determined in each horizon of four contrasting soil profiles using a modification of the approach used to determine heterotrophic potential in aquatic environments. Short‐term mineralization rates were determined at 12 concentrations ranging from 5 to 10 000 µg phenol kg−1 dry soil and the data were reduced using a hyperbolic saturation model similar to that used for describing enzyme kinetics. The kinetic terms Vmax and K′ were estimated using nonlinear regression. Phenol was mineralized in all soil samples at each concentration examined. The Vmax values ranged from 0.018 to 22.4 ng phenol kg−1 dry soil s−1; K′ values ranged from 20 to 2355 µg phenol kg−1 dry soil. Generally within each soil profile, Vmax tended to decline with increasing depth; however, the magnitude and pattern of this decline varied widely according to soil type. The Vmax in the Ap horizons (3–15 cm) ranged from 2.49 to 13.8 ng kg−1 dry soil s−1. The Vmax in the B22t horizons (30–101 cm) ranged from 0.839 to 2.65 ng kg−1 s−1, and Vmax in the deepest horizons (81–187 cm) ranged from 0.145 to 4.75 ng kg−1 dry soil s−1. This study indicates that soil horizon and soil type are important determinants of the biodegradation of phenol, a potential groundwater pollutant, as it passes through the soil column.
An Ion‐association Model for Highly Saline, Sodium Chloride‐dominated Waters
Authors: Sposito Garrison , Traina Samuel J. 
Published: July 2010

AbstractAn empirical ion‐association model for concentrated aqueous solutions in which NaCl is the principal solute was developed for incorporation into the computer program GEOCHEM. The model involved the use of the Davies equation to calculate the activity coefficients of charged species and other semiempirical equations based in statistical mechanics to calculate the activity coefficients of neutral complexes. Model validation was initiated through prediction of the solubilities of gypsum, amorphous silica, and barite in NaCl solutions and other Na‐salt solutions. Predicted solubilities usually agreed with measured values to within ±5% at ionic strengths up to 2 kmol m−3 (mol L−1). These encouraging results suggest that the model, although limited in scope and validation, will be useful for chemical speciation calculations on highly saline soil solutions and brines.
Residual Effects of Sewage Sludge on Soybean: I. Accumulation of Heavy Metals
Authors: Heckman J. R. , Angle J. S. , Chaney R. L. 
Published: July 2010

AbstractThe potential for excessive crop uptake of heavy metals from land previously amended with sludge is of concern because of the persistence of heavy metals. Field studies were therefore conducted at two locations in 1983 and 1984 to examine the residual effects of sewage sludge on heavy metal uptake by soybean [Glycine max (L.) Merr.]. The Fairland plots (Typic Hapludults) had been amended with two rates of anaerobically degested sludge in 1975. The Beltsville plots (Typic Paleudults) had been established in 1976 with limed‐anaerobically digested, limed‐raw, limed‐compost, or heat‐treated sludge and in 1978 with Nu‐Earth (Chicago, IL) anaerobically digested sludge. Treatments consisted of various sludge rates and pH regimes. The concentrations of metals in soybean shoots at the R4 growth stage varied according to sludge type, application rate, and soil pH. Metal uptake from low metal, limed sludges was similar to that of controls. Metal uptake was, however, increased by unlimed sludges that were high in metal content. Digested sludge linearly increased shoot metal concentrations of Zn, Cd, Cu, and Ni. Compared to the unamended control, soybean Zn increased from 24 to 165 mg kg−1 and Cd increased from 0.06 to 0.25 mg kg−1 at the 112 Mg ha−1 rate. The shoot Cd concentration was over seven times higher from Cd rich Nu‐Earth sludge as compared to the other sludges. Shoot Zn and Cd concentrations exhibited significant linear and quadratic relationships with rates of heat‐treated and Nu‐Earth sludge. There was a greater response of shoot Zn and Cd accumulation to sludge rate at low soil pH. At the 100 Mg ha−1 rate of Nu‐Earth sludge, soybean Zn and Cd concentrations, respectively, were 59 and 1.75 mg kg−1 at soil pH 6.4 and 84 and 2.54 mg kg−1 at soil pH 5.8. These results indicate that sludge composition and soil pH can have a substantial influence on soybean metal uptake for at least 9 yr after the initial sludge application.
Chemistry of Tension Lysimeter Water and Lateral Flow in Spruce and Hardwood Stands
Authors: Joslin J. D. , Mays P. A. , Wolfe M. H. , Kelly J. M. , Garber R. W. , Brewer P. F. 
Published: July 2010

AbstractThe concentrations of H+, NO−3, SO2−4, soluble Al, and undissociated acidity were measured in throughfall, soil solution, and streamflow during five rainfall events on two steeply sloping forested sites in the Great Smoky Mountains. The sources and sinks of these chemical species on a spruce‐birch (Picea rubens Sarg.‐Betula lenta L.) site were compared to those on a hardwood site. The chemistry of water collected in zero‐tension lateral flow collectors during storm events was contrasted with water collected at corresponding depths in tension lysimeters. Tension lysimeter samples from the spruce site had much higher concentrations than those from the hardwood site of H+ (3–7 ×), SO2−4 (1.5–2 ×), Al (2–5 ×), and undissociated acidity (1.5–2 ×). Baseflow from a first‐order stream draining the spruce site was significantly higher in Al and H+ than hardwood site baseflow. On both sites the largest sources of H+ and undissociated acidity were throughfall (incident precipitation + canopy sources) and the O horizon; on the spruce site the O horizon was the predominant source of each. Aluminum and SO2−4 also increased dramatically with passage through the O horizons, especially on the spruce site. Only the spruce site generated appreciable lateral flow. Nitrate, undissociated acidity, and Al concentrations in spruce site lateral flow were not significantly (p <0.05) different from those in corresponding tension lysimeter samples. Electrical conductivity and concentrations of H+ and SO2−4, however, were higher in lateral flow from spruce site B horizons than in corresponding tension lysimeter water. Reduced soil contact time and contact surface area were hypothesized reasons for the ineffectiveness of these B horizon sinks with regard to rapid lateral flow. Lateral flow pathways on the spruce site may have also bypassed sinks for Al and undissociated acidity that exist in the lower mineral horizons and bedrock zone. Stream pH depressions during stormflow may be related to rapid subsurface flow and interflow emanating from these acidic spruce‐birch sites.
Soil Clogging During Subsurface Wastewater Infiltration as Affected by Effluent Composition and Loading Rate
Authors: Siegrist Robert L. 
Published: July 2010

AbstractThe soil clogging effects of wastewater effluent composition and loading rate were investigated in pilot‐scale infiltration cells installed in situ in the structured silty clay loam subsoil of a Typic Argiudoll (fine‐silty, mixed, mesic). Over a 70‐month period domestic septic tank effluent (DSTE), graywater septic tank effluent (GSTE) and tapwater (TW) were intermittently applied in an average of 5.2 doses/d to yield daily loading rates of 1.3, 2.6, and 5.2 cm/d. Soil clogging was negligible in all TW treatments and in the GSTE treatments at 1.3 and 2.6 cm/d. In the GSTE treatments at 5.2 cm/d and in all DSTE treatments, severe soil clogging led to continuous ponding of the soil infiltrative surfaces. A logistic model fit to the experimental data confirmed that soil clogging development was highly correlated with the cumulative mass density loadings of total biochemical oxygen demand and suspended solids. After 62 and 70 months of loading, soil properties were determined with depth. Clogged infiltrative surface zones exhibited significant accumulations of organic materials at the infiltrative surface and within the first few millimeters of the soil matrix. This field study demonstrated that higher quality wastewater effluents can be discharged to subsurface infiltration systems at hydraulic loading rates in excess of those utilized for DSTE without stimulating soil clogging development.
Tilted‐bed Simulation of Erosion and Chemical Runoff from Agricultural Fields: II. Effects of Formulation on Atrazine Runoff
Authors: Wauchope R. Don 
Published: July 2010

AbstractThe concentrations and loads of atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine] in runoff water from “tilted‐bed” soil trays under intense simulated rainfall were similar to losses reported in field studies. Atrazine was applied at rates of 2.7 to 3.4 kg/ha as emulsion, wettable powder, dispersible liquid, and dispersible granule formulations, on a loam soil in eight 2.2‐ by 1.2‐m trays tilted to 1.3% slope. In simulated storms in which 3 cm of rainfall fell in 5 min and generated 0.7 cm of runoff, total atrazine losses ranged from 4 to 8% for the emulsion and dispersible‐liquid applications and 9 to 12% for the dispersible‐granule and wettable‐powder formulations. One‐fifth of the total losses occurred in the first liter of the runoff. This initial “flush” loss of atrazine in the water front resulted in concentrations up to 23 mg/L in the first runoff depending on the differing particle sizes of the spray deposits of the different atrazine formulations. The tilted‐bed/rainfall simulator system appears to offer promise as an inexpensive and convenient supplement to field experiments for characterizing pesticide movement or yield in runoff and evaluating the potential of new chemicals for nonpoint source pollution.
Nitrogen Mineralization in Sewage‐sludge‐Amended Coal Mine Spoil and Topsoils
Authors: Voos Gerard , Sabey B. R. 
Published: July 2010

AbstractA 16‐week laboratory incubation was conducted to determine the rate of net N mineralization in sewage‐sludge‐amended coal mine spoil, two topsoils, a 1:1 mixture of the spoil with each topsoil, and a quartz sand. Sewage sludge was added at rates of 0, 40, 80, and 120 Mg ha−1, which added 0, 1630, 3260, and 4890 kg N ha−1, respectively. The total amount of inorganic N that accumulated during the experiments increased significantly as the rate of sewage sludge addition increased in each of the materials and mixtures tested. However, the rate of sludge addition did not have a similar effect on the amount of NO3‐N accumulated. The soil materials did affect the amount of NO3‐N that accumulated in 16 weeks. Little or no NO3‐N had accumulated in any of the sand treatment samples and only small amounts were produced in the spoil. Ammonium‐N increased with increasing rates of sewage sludge in all materials and mixtures examined. The rate of ammonification was more stable after the 8‐week sampling interval in most cases. Mineralization of organic N added with the sewage sludge varied between 10 to 34%. At all rates of sludge addition, more organic N was minerlized in stock piled topsoil than in the other materials. A nonlinear least squares regression equation for N mineralization as first‐order kinetics slightly overestimates N mineralization in the 4‐ to 8‐week interval and slightly underestimated N mineralized through 16 weeks.
Element Leaching and Capillary Rise in Sandy Soil Cores: Experimental Results
Authors: Sheppard Marsha I. , Thibault D. H. , Mitchell J. H. 
Published: July 2010

AbstractDisposal of hazardous wastes by burial is a common practice. This practice usually involves several barriers to the migration of the wastes, one of which is the unsaturated soil zone. The long‐term consequences of capillary rise of water and its dissolved contaminants through the unsaturated soil is not easy to assess. Similarly, downward migration after a surface contamination event, such as irrigation with contaminated groundwater, is a complex process. This study examines both the leaching and capillary rise of Tc, I, Np, U, Th, Cs, Cr, and Mo through a sandy soil. Eighty undisturbed soil cores from a forest floor were contaminated, half were contaminated 10 cm from their base to simulate contact with contaminated groundwater (groundwater cores), and the other half were contaminated below the litter layer to simulate soil surface deposition (leaching cores). Cups at the base of the cores served as receptacles for groundwater or for leachate. The cores were placed in the ground with their surfaces exposed to natural rainfall. After 1 yr, half of the cores were exhumed. Soil moisture and temperature conditions in the cores reflected the trends of moisture and temperature at the coring site. Leachate analyses and exhumation data of the leaching cores indicated element mobility as Tc ≥ I >> Mo ≥ Cr >>> U ≥ Np, Cs, Th, with Tc the most mobile and Th the least mobile. Only Tc, I, Mo, and Cr passed through the cores in the leachate in the first year. The groundwater cores showed that Tc, I, Mo, and Cr are most likely to reach surface soils from contaminated groundwater based on one year of data. Partition coefficient (Kd) values for Tc, I, and U from batch sorption experiments were compared with Kd values obtained from the exhumation porewater and soil, by soil horizon.
Speciation of Trace Inorganic Contaminants in Plants and Bioavailability to Animals: An Overview
Authors: Cataldo D. A. , Wildung R. E. , Garland T. R. 
Published: July 2010

AbstractThe movement of both essential and pollutant trace elements through agricultural food chains is a complex problem, influenced in part by plant‐mediated changes in trace element speciation that may alter the rate and extent of gastrointestinal absorption after ingestion of plant tissues by animals. An overview is provided of a series of investigations undertaken to describe the processes governing the chemical behavior of several cations (Pu, Ni, Cd, and Fe) and anions (Tc, Se, and S) during transport in the plant xylem and after deposition in plant tissues. Cations were generally present in xylem exudale as organic acid, amino acid, and peptide complexes specific to the element, whereas anions tended to remain in the inorganic forms initially absorbed by the root. Once deposited in tissues, both cations and anions were associated with more complex, but soluble, plant metabolites. The cations (Pu, Ni, Cd) were directly associated with >10 000 molecular weight proteins, whereas the anions (Se and Tc) appeared to undergo chemical reduction and incorporation into proteins using enzymatic processes functioning for S metabolism. The importance of these plant processes on gastrointestinal absorption was demonstrated for Pu and Tc, which differed markedly in their behavior in plants and animals.
Characterization of Soluble Organic Compounds and Complexation of Copper, Nickel, and Zinc in Extracts of Sludge‐amended Soils
Authors: Dudley L. M. , McNeal B. L. , Baham J. E. , Coray C. S. , Cheng H. H. 
Published: July 2010

AbstractAn anaerobically digested, municipal sewage sludge was mixed with an acid and a neutral soil and incubated for periods of up to 30 weeks at 25 ± 2°C and approximately −33 kPa water potential. Aliquots from saturation pastes were passed through a Sephadex™ G‐15 gel filtration column and the fractions analyzed for total soluble C, Cu, Ni, and Zn. Infrared spectra were recorded for fractions containing a soluble‐C or metal‐concentration maximum. Copper was associated with soluble organic compounds throughout the 30‐week incubation, and through 4 weeks was found primarily in fractions containing amide functional groups. Zinc generally eluted in a region suggesting the presence of Zn‐inorganic complexes. Soluble Ni was associated with organic compounds at high pH during the initial 4 weeks of incubation, but in extracts of subsequent incubations the element partitioned about evenly between organic and inorganic complexes below neutral pH. The relative strength of adsorption bands in the IR spectra, which were diagnostic for polysaccharides, proteins, and amino acids, declined over the study period. The dominant spectral features for extracts of sludge‐soil mixtures incubated 4 weeks or longer were diagnostic bands for aromatic and aliphatic carboxylic acids. A least squares (L2) approximation to proton titration curves was used to select a subset of ligands, which provided the smallest error term. The set of ligands from which the subset was selected was acetate, citrate, maleate, phthalate, salicylate, arginine, lysine, ornithine, and valine. Total soluble concentrations of Ca, Cu, Ni, Zn, Cl, NH3, PO4 and organic ligands, and pH and PCO2 values (0.03 kPa), were used to calculate ion speciation in the extracts via the computer program GEOCHEM. Values for the fractions of total soluble Cu, Ni, and Zn bound by soluble organic matter as predicted by GEOCHEM agreed with values determined by gel separation.
Nitrous Oxide Production throughout the Year from Fertilized and Manured Maize Fields
Authors: Cates R. L. , Keeney D. R. 
Published: July 2010

AbstractTwo field sites on a loam soil were established to monitor N2O concentration in the soil atmosphere and rate of emission from the soil surface. The sites were cropped to maize (Zea mays L.) and managed at two high‐N levels (181 or 237 kg N ha−1). Both sites received 168 kg N ha−1 as feedlot cattle (Bos taurus) manure (preplant‐incorporated) and 13 kg N ha−1 as NH4NO3 fertilizer in the row at planting. One site (Site B) received additional soil‐incorporated N (56 kg N ha−1) as urea. Fluctuations in N2O emissions from the two sites were temporally similar, and differed only in magnitude with Site A (no additional fertilizer), emitting about 3.6 kg N2O‐N ha−1 yr−1 and Site B about 5.2 kg N2O‐N ha−1 yr−1, or about 2% of the N applied. Most of the N2O was emitted between mid‐June and the end of July when the soil was warm and NH+4‐N was present, and at spring thaw (late March the following year) when soils were cold and near water‐saturated. High N2O emissions during the growing season occurred following precipitation events, and hence were associated with high soil water and probably with the initiation of soil drying. Nitrous oxide production was continuous during winter months, presumably a result of denitrification. The N2O concentration in the profile of the frozen soil increased to high levels (nearly 2000 µL L−1 N2O at Site B) before spring thaw. At thaw, nearly 330 d after application of the N amendments, an apparent physical release period occurred and N2O flux was far higher (about 50 g N2O‐N ha−1 d−1) than at most times during the growing season.
Trees as Monitors of Tritium in Soil Water
Authors: Kalisz P. J. , Stringer J. W. , Volpe J. A. , Clark D. T. 
Published: July 2010

AbstractTritium (3H) activities in the foliage of forest trees were found to reflect 3H activities in soil water along the perimeter of a retired low‐level radioactive waste disposal site. Spatial variability in foliage 3H activity clearly delineated patterns of 3H in soil water as deep as 3 m. Late summer increases in foliage 3H activity paralleled increases in soil water activity and also suggested greater uptake of water from deep reservoirs after surface soils had dried out. White and chestnut oak (Quercus alba L. and Q. prinus L.) dominated the study area and were good monitors of 3H, regardless of tree size. Spatial patterns of 3H in foliage of these species over a 5‐ha watershed were interpretable in terms of the local landscape and the probable pathways of movement of contaminated water originating on the disposal site. Results of this study suggest that trees and other deeply rooted plants may serve as simple and effective monitors of soil water contamination and may therefore be useful additions to permanent monitoring systems.