bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for Movement of Heavy Metals in a Soil Irrigated with Untreated Wastewater
Authors: Schirado T. , Vergara I. , Schalscha E. B. , Pratt P. F.
Published: July 2010

A Vertisol irrigated for over five decades with an untreated municipal wastewater had elevated levels of DTPA extractable Cd, Co, Cu, Mn, Ni, and Zn in the cultivated layer of the soil as compared to lower layers. Total Co, Ni, and Zn were uniformly distributed in the 150‐cm depth of the soil profile, total Cu increased with depth and total Cd, Cr, and Mn had higher concentrations in the cultivated layer than in some deeper layers. Assuming that the added metals had accumulated in the cultivated layer of the soil and assuming uniform distributions of metals in the soil profile at the start of irrigation with wastewater, the amounts of metals added would have produced increased concentrations in the cultivated layer. These expected differences were not found, except for Mn. These results suggest that the metals Cd, Co, Cr, Cu, Ni, and Zn may have migrated downward from the cultivated layer and are now distributed throughout the soil profile or leached below the depth of sampling.
Distribution of Heavy Metals in Waste Drilling Fluids Under Conditions of Changing pH
Authors: Deeley G. M. , Canter L. W.
Published: July 2010

A laboratory study was conducted to determine the influence of pH on the distribution of arsenic (As), barium (Ba), chromium (Cr), and lead (Pb) in three different oil and gas well drilling fluid wastes. Samples were obtained from disposal pits and equilibrated in the laboratory under controlled conditions of pH. A sequential extraction procedure was then used to fractionate the selected elements into the fractions of aqueous, KNO3‐extractable, H2O‐extractable, NaOH‐extractable, EDTA‐extractable, and HNO3‐extractable phases. The chemical fractions present at each pH were then compared, thus providing insight into the potential of mobilization of As, Ba, Cr, and Pb into ground‐ or surface waters. The majority of each of the elements studied was found in the NaOH‐extractable, EDTA‐extractable or HNO3‐extractable fractions except for one waste which contained a major portion of the total barium in the KNO3‐extractable fraction. Generally, decreasing pH caused a shift from the more stable HNO3‐extractable fraction toward less stable EDTA‐extractable, NaOH‐extractable, or KNO3‐extractable fractions. In no case was there a substantial release to the aqueous phase with changing pH. The significance of these results is that with pH changes to be expected in the natural environment there is not likely to be a major release of As, Ba, Cr, and Pb from drilling fluid waste disposal pits. The lower pH values (< 4) which might produce some impact are unlikely to occur in the environment because the wastes themselves have a large neutralizing capacity.
Nickel, Cadmium, and Selenium Levels in Native Soil, Overburden, and Spoil Materials
Authors: Pitt J. L. , Hossner L. R. , Melton J. R.
Published: July 2010

Nickel (Ni), cadmium (Cd), and selenium (se) analyses showed that there was no significant difference in the concentration of these elements when compared over the three sample types examined (native soil, overburden, and spoil materials obtained from four surface mining operations in Texas). The soils belong to the Paleustalf, Paleudult, Hapludalf, and Paleudalf Great Groups. Ranges in total concentrations of the individual elements were 4.01 to 71.4 mg kg−1 Ni, 0.00 to 2.46 mg kg−1 Cd, and 0.04 to 10.7 mg kg−1 Se for the native soil, overburden, and spoil samples. At each site, the geological environments of deposition had significantly different levels of Ni, Cd, and Se. Depositional environments containing higher concentrations of fine materials (Backswamp, flood basin, etc.) had the highest concentrations of Ni and Cd. Selenium was highest in the lignite and deposits closely associated with the lignite. Results of this study indicate that no significant elevation of total Ni, Cd, and Se would be expected from the complete mixing of overburden following the surface mining operation.
Comparison of Methods for Estimating Sulfate Export from a Forested Watershed
Authors: Dann M. S. , Lynch J. A. , Corbett E. S.
Published: July 2010

Seven methods of estimating sulfate export from a forested watershed in central Pennsylvania were compared. One method involved simple linear regression of discharge and concentration data, two methods were based on regression models in which the concentration data were stratified by flow frequency or duration, two methods weighted the mean concentration by discharge, one method used a simple unweighted mean concentration, and one weighted export according to the length of the sampling period interval. The regression models produced the highest export estimates but were considered statistically invalid because the data set did not adhere to the statistical requirements of independence, normality, and linearity. Weighted and unweighted mean concentration methods gave the lowest estimates of export because they gave less emphasis to high flows during which the majority of sulfate was exported from the watershed. The period‐weighted method gave intermediate to high export estimates because it took into consideration the large export of sulfate during high flows. This method appeared to offer the best estimate of sulfate export from the watershed studied within the conditions and limitations of the data set. Although limited to sulfate export from a forested watershed, these results would appear to be applicable to any ion, particularly if the solute concentration of the ion is flow related.
Characterization of Reclaimed Mined Land With and Without Topsoil
Authors: Chong S. K. , Becker M. A. , Moore S. M. , Weaver G. T.
Published: July 2010

Research was conducted on two field plots to ascertain whether topsoil restoration is necessary hydrologically and physically in mined land reclamation. Plot 1 was reclaimed with mixed B‐ and C‐horizon material, and Plot 2 with the same material as Plot 1 but with 0.2 m of topsoil added on the surface. The mixed B and C materials were restored with a shiftable conveyor belt and the stockpiled topsoil was spread by earth scrapers. Both field plots were divided into 25 subplots. The hydrological and physical characterization was limited to the top 0.2 m of the soil. The result showed that nontopsoil had an average bulk density of 1.5 Mg m−3 which is about 15% higher than that of the topsoil plot. The hydraulic conductivity, macroporosity, and drainage rate of topsoil materials were higher, but the sorptivity and infiltration rate of the two plots were not significantly different. Since this research was limited to 0.2 m of surface soil, it did not provide enough information to decide whether topsoil replacement is necessary or whether B and C material is an adequate rooting medium. The study did demonstrate a simple technique for detailed characterization of the physical and hydrological properties of reclaimed mined land.
Time‐dependent Changes in Soluble Organics, Copper, Nickel, and Zinc from Sludge Amended Soils
Authors: Dudley L. M. , Mc Neal B. L. , Baham J. E.
Published: July 2010

An acidic western Washington soil and a near‐neutral eastern Washington soil were each mixed with anaerobically digested Seattle‐METRO sewage sludge and incubated in triplicate at 25 ± 2°C and approximately −33 kPa water potential for 1, 2, and 4 d and 1, 2, 4, 10 and 30 weeks. At the end of each incubation period, saturation pastes were made using 0.01 M CaCl2 and vacuum extracted. Total soluble C, Cu, Ni and Zn, as ‐ell as NH4 + NH3, NO3‐N, ortho‐P, and pH were measured in the extracts. High NH4 + NH3 values produced in the first 2 weeks of incubation caused the pH to increase into the alkaline range. Soluble C values increased during this period, and soluble Cu values increased despite the increasing pH, apparently because of organic complex formation. Soluble Zn declined during the same period. Soluble Ni possessed intermediate chemical behavior, as it appeared to be influenced both by a solid phase with pH dependent solubility and by ability to form organic complexes. Nitrification during incubations longer than 4 weeks led to a pH decline and increased Zn and Ni levels once more. Decreasing Cu levels were also associated with this period, likely due to losses of soluble organic materials via oxidation to CO2.
Mineralization of Nitrogen in Soils Amended with Organic Wastes
Authors: Chae Y. M. , Tabatabai M. A.
Published: July 2010

This study was conducted to compare the mineralization of N in soils amended with various sewage sludges, animal manures, and plant materials. In this work, field‐moist soils mended with organic waste materials at a rate of 50 Mg ha−1 were mixed with glass beads, packed in leaching columns, leached with 5 mM CaCl2 to remove the mineral N, and incubated at 30°C. The leaching procedure was repeated every 2 weeks for a total of 26 weeks. The leachates were analyzed for NO−3‐N. With the exception of alfalfa (Medicago sativa L.), in general, mineralization of N exhibited a slow initial rate, which was indicative of a lag period, followed by a rapid increase in rate, and subsequent slow rate of N release. The total N mineralized from the organic waste materials varied considerably, depending on the type of soil and organic waste material. The total N mineralized in five unamended soils ranged from 91 mg N kg−1 with Lester soil to 337 mg N kg−1 with Webster soil. The amounts of N mineralized in soils amended with sewage sludges and animal manures ranged from 156 to 668 mg N kg−1 soil and from 176 to 617 mg N kg−1 soil, respectively. The total N mineralized in soils amended with plant materials ranged from 0 in 3 soils amended with sawdust to 983 mg N kg−1 for Webster soil amended with alfalfa. Expressed as a percentage of total organic N added to soils, the N mineralized ranged from 1 to 58% for sewage sludges and from 13 to 67% for animal manures. The percentage of organic N mineralized in plant materials ranged from 3% for soybeans to 97% for alfalfa. Addition of corn residue or sawdust resulted in decreases in N mineralization ranging from 3 to 687%. Soil types have marked effects on the mineralizable N (No) pools and firstorder rate constants (k).
Competitive Adsorption of Heavy Metals by Soils
Authors: Elliott H. A. , Liberati M. R. , Huang C. P.
Published: July 2010

The competitive adsorption of Cd, Cu, Pb, and Zn from 0.025 M NaClO4 solutions onto four soils with differing chemical properties was investigated with batch adsorption experiments. For two mineral soils, adsorption under acidic conditions (pH 5.0) followed the sequence Pb > Cu > Zn > Cd, which corresponds to the order of increasing pK for the first hydrolysis product (e.g., PhOH+) of the metal ions. In contrast, the order of selectivity for two soils containing 20 to 40 g kg−1 organic C was Pb > Cu > Cd > Zn, suggesting that organic matter (OM) increased Cd retention preferentially over that of Zn. When accompanied by a sizable reduction in cation exchange capacity (CEC), extraction of soil OM markedly reduced adsorption of all four metals. However, only Cd and Cu adsorption were appreciably smaller for a soil that maintained a sizable CEC following OM removal. Lead, and possibly Zn, adsorption by soils with substantial inorganic exchange sites may be unresponsive to organic waste amendments. For Cd and Cu, increased soil OM should restrict mobility and bioavailability, at least under acidic conditions where soluble metal complex formation is limited.
Fate of Thiobencarb and Molinate in Rice Fields
Authors: Ross L. J. , Sava R. J.
Published: July 2010

The fate of thiobencarb (S‐[4‐chlorobenzyl] N,N‐diethylthiolcarbamate) and molinate (S‐ethyl hexahydro‐1 H‐azepine‐1‐carbothioate) in air, water, soil, and vegetation of rice (Oriza sativa L.) fields was documented for 32 d following application. Analysis of variance was used to determine if holding periods facilitated herbicide dissipation in water prior to release to drainage canals. Maximum thiobencarb concentrations in air, water, soil, and vegetation were 1.4 µg/m3, 576 µg/L, 3860 µg/kg, and 1750 µg/kg, respectively. During the 6‐d holding period, thiobencarb concentrations in water did not decline significantly, indicating that this period was not sufficient to facilitate dissipation. The mass balance budget indicated that thiobencarb was predominantly distributed between water (34%) and soil (43%) and <1% was located in air and vegetation. Maximum molinate concentrations in air, water, soil, and vegetation were 48 µg/m3, 3430 µg/L, 2210 µg/kg, and 918 µg/kg, respectively. Molinate concentrations in water declined significantly during the holding period, indicating that this water‐management practice facilitated dissipation of molinate. The mass balance budget indicated that as much as 81% of the molinate applied was dissolved in water followed by soil (10%), air (9%), and vegetation (<1%). Partitioning of these herbicides in the field was closely related to their physico‐chemical properties.
Nutrient Uptake and Growth Responses of Virginia Pine to Elevated Atmospheric Carbon Dioxide
Authors: Luxmoore R. J. , O'Neill E. G. , Ells J. M. , Rogers H. H.
Published: July 2010

One‐year‐old Virginia pine (Pinus virginiana Mill.) seedlings with native or Pisolithus tinctorius mycorrhizal associations were grown in pots with soil low in organic matter and in cation exchange capacity and were exposed to one of five atmospheric CO2 levels in the range of 340 to 940 µL/L in open‐top field chambers. The mean dry weight of the seedlings increased from 4.4 to 11.0 g/plant during the 122‐d exposure period. Significant increases in dry weight and uptake of N, Ca, Al, Fe, Zn, and Sr occurred with CO2 enrichment. Greater chemical uptake was associated with greater root weight. Specific absorption rates for chemicals (uptake per gram of root per day) were generally not affected by CO2 enrichment. The uptake of P and K was not increased with elevated CO2, and these elements showed the greater nutrient‐use efficiency (C gain per element uptake). The nutrient‐use efficiency for N and Ca was not influenced by atmospheric CO2 enrichment. Large increases in Zn uptake at high CO2 suggested an increase in rhizosphere acidification, which may have resulted from the release of protons from the roots, since it was estimated that cation uptake increasingly exceeded anion uptake with CO2 enrichment. Potassium, P, and NO−3 concentrations in the pot leachate decreased with higher CO2 levels, and a similar trend was found for Al and Mg. These results suggest that soil‐plant systems may exhibit increased nutrient and chemical retention at elevated atmospheric CO2.
Determination of Alkyllead Salts in Runoff, Soils, and Street Dusts Containing High Levels of Lead
Authors: Blais J. S. , Marshall W. D.
Published: July 2010

The determination of aikyllead salts in environmental samples that contain high levels of inorganic Pb is difficult because of poor recoveries and the formation of artifacts during the isolation and derivatization procedures. A modified procedure has been developed in which alkyllead salts are selectively extracted complexometricaliy from samples which contain up to 1000 mg Pb2+ kg−1. The extracts are butylated and analyzed by gas chromatography‐atomic absorption spectroscopy. Re‐extraction of the sample with methyl isobutyl ketone‐dithizone permits the recovery of Pb2+. This procedure was applied to rainwater runoff, soils, and street dusts from urban environments. Ethyllead salts but not methyllead salts were detected in all samples. Concentrations of these analytes were significantly correlated (P <0.01) with levels of extractable Pb2+ in these samples but not with total Pb.
Identification of Water Quality Differences in Nevada Through Index Application
Authors: Miller W. W. , Joung H. M. , Mahannah C. N. , Garrett J. R.
Published: July 2010

The assessment of periodic changes in water quality and uniform control standards application has been difficult to attain. A potential solution to this problem is the utilization of water quality indices for preliminary screening of data and identification of geographic areas, chronological periods, and possible source and cause of water quality changes. The purpose of this investigation was to demonstrate a practical use and application of a water quality index in Nevada as an existing option for those who must assess water quality changes on a continual basis. The study examined water quality trends in portions of the Colorado, Humboldt, Snake, Walker, and Carson River Basins, Nevada, through application of an existing water quality index to historical data from control point and adjacent monitoring stations. Index ratings were responsive in characterizing changes in water quality status relative to seasonal trends and geographic location. Identification of average annual and single value control criteria violation in terms of which parameter and degree of violation was facilitated through index application. Frequency and magnitude of impact on overall water quality status was also identified. Future use of indices in this manner should prove a valuable tool in meeting legislative water quality management strategies.
Nitrate Leaching Through Sandy Soil as Affected by Sprinkler Irrigation Management
Authors: Hergert Gary W.
Published: July 2010

Nitrate‐N (NO3) leaching losses were quantified for irrigated corn (Zea mays L.) grown on a Valentine sand using a ceramic candle extraction system buried at 1.5‐m depth. Irrigation rates were 85% and 130% of evapotranspiration (ET). Total dry matter, grain yield and crop N uptake were not significantly affected by irrigation level. During the two year study average annual flow‐weighted NO3‐N concentrations in extracted soil water ranged from 28.3 to 75.2 mg NO3‐N L−1 for 0.85 and 1.3 ET irrigation levels, respectively. In 1976 the 0.85 ET treatment had 37 ha‐mm of soil water percolation and leaching of 12 kg NO3‐N. The 1.3 ET treatment lost 191 ha‐mm of percolation and 75 kg NO3‐N. In 1977 132 ha‐mm of soil water was lost by percolation and 109 kg NO3‐N ha−1 for 0.85 ET and 182 ha‐mm and 146 kg NO3‐N ha−1 for the 1.3 ET irrigation level. The higher soil water percolation and NO3‐N losses in 1977 resulted from over‐winter precipitation and early spring leaching of the previous year's residual nitrate. In‐season NO3‐N leaching was reduced by matching irrigation to ET. To effectively reduce NO3‐N leaching N fertilizer rates must match crop yield requirements to reduce soil NO3‐N carryover and irrigation scheduling must be used on sands.
Trace Element and Salt Movement in Retorted Oil Shale Disposal Sites
Authors: Stark John M. , Redente Edward F.
Published: July 2010

The direction and amount of salt and trace element movement within retorted shale disposal piles is a major environmental concern. This study examines the redistribution of soluble salts and trace elements (As, B, Cd, Cu, F, Fe, Mn, Mo, Na, Ni, Pb, Se, and Zn) in retorted shale test plots with different topsoil treatments 6 yr after construction. Topsoil treatments included no topsoil, no topsoil and leached with 76‐cm water, 30‐cm topsoil, 60‐cm topsoil, 90‐cm topsoil, 60‐cm topsoil and capillary barrier, and a disturbed soil control (no retorted shale). Soluble salts (especially Na salts) and F showed considerable movement both upwards and downwards in the profiles. Molybdenum showed some movement in both directions. The remaining elements showed little or no movement out of the shale layer. Increasing topsoil depths resulted in less salt or trace element movement in either direction. Use of a capillary barrier between the topsoil and retorted shale prevented upward migration of salts and trace elements. After 6 yr the exposed shale treatments (both leached and unleached) continued to have considerably higher salt and trace element contents than any other treatment. Because of limited rooting depths, deeper percolation of moisture is occurring on plots containing retorted shale than on the control plot.
Fate of Ammonium in a Gulf Coast Estuarine Sediment
Authors: Smith C. J. , De Laune R. D.
Published: July 2010

The loss of 15N labeled (NH4)2SO4 applied uniformly to estuarine sediment was investigated under laboratory conditions. The recovery of 15N labeled NH+4‐N in the NH+4, NO−2 + NO−3, and organic N pools was determined at depth within the sediment cores. Concentrations of NH+4‐N generally increased with depth, with largest gradients near the surface. There was significant ammonification in underlying anaerobic sediment with a consistent increase in concentration of NH+4 being observed with increasing time of incubation. Surface sediment became depleted in 15NH+4‐N with time of incubation due to nitrification. Nitrogen‐15 losses occurred in the surface layer predominately from nitrification‐denitrification of the NH+4. Net NH+4 incorporation into the organic N fraction (immobilization) was greater in the aerobic surface sediment than in the underlying anaerobic sediment. In contrast, after 70 d of incubation, anaerobic sediment partitioned 65 ± 9% of the added 15N in the inorganic NH+4‐N pool and 27 ± 7% in the organic N pool. Total 15N losses increased with time of incubation and ranged from 9 to 26% following the addition of 3, 6.5, and 17 mg 15N excess kg−1 dry sediment.
Predicting the Fate of Nonvolatile Pesticides in the Unsaturated Zone
Authors: Wagenet R. J. , Hutson J. L.
Published: July 2010

A simulation model of the fate of nonvolatile pesticides in the unsaturated zone is reported. The model was developed from basic principles of water and solute movement under transient field conditions, and considers water flow and resulting pesticide displacement, plant extraction of water and pesticide (if quantified), and pesticide sorption and degradation during transport. The finite‐differencing procedures were developed to provide substantial flexibility of initial and boundary conditions, allowing consideration of layered soils, multiple rainfall or evapotranspirational cycles, application of chemical in wet or dry form, plant growth, and several bottom boundary conditions. Application of the model to measured field data of aldicarb [2‐methyl‐2‐methylthio)propionaldehyde O‐(methylcarbanoyl)oxime] movement indicates that the modeling approach can provide reliable and useful estimates of the mass flux of water and nonvolatile pesticide in unsaturated soil. Sensitivity of the model to variability in soil hydraulic properties and aldicarb transformation (degradation) rates is also presented.
Crop Effects from Air Pollutants in Air Exclusion Systems vs. Field Chambers
Authors: Olszyk David M. , Bytnerowicz Andrzej , Kats Gerrit , Dawson Philip J. , Wolf Joanne , Thompson C. Ray
Published: July 2010

Crop growth and yield effects from exposure to ambient O3 were evaluated with air exclusion systems and open‐top or closed‐top field chambers. Alfalfa (Medicago sativa L.) studies with three harvests in 1983 and three in 1984 indicated that during the summer growing season, plants respond similarly to ambient O3 when exposed in air exclusion systems and inboth open‐ and closed‐top chambers. Filtering ambient O3 in general increased plant growth in both air exclusion systems and chambers. Plant growth was most similar between nonfiltered air exclusion systems chambers and outside plots, somewhat altered in opentop chambers, and greater in closed‐top chambers than the other facilities. During the fall, alfalfa growth was similar in air exclusion systems and outside plots, whereas growth was greater in open‐top chambers than in outside plots.
Biochemical Oxygen Demand of Agricultural Runoff
Authors: Schreiber J. D. , Neumaier E. E.
Published: July 2010

Using an electrolytic respirometer, agricultural runoff from seven crop and tillage practices were studied to determine the 5‐d biochemical oxygen demand (BOD5). Mean BOD5 concentrations for the practices ranged from 10 to 25 mg O2 L−1 as compared to 4 to 56 mg O2 L−1 for individual storm events. In general, there was no difference in BOD5 concentrations between conventional and no‐till practices. Biochemical oxygen demand‐time relationships were found to best fit a first‐order reaction equation. The aqueous phase was the dominant source of BOD5, amounting to 64 ± 17% (1 SD) of the total BOD5 in runoff from notill soybeans, double‐cropped with winter wheat (Triticum aestivum L.). However, additional data indicate that conventional tillage practices, producing higher sediment concentrations, may result in a greater proportion of the BOD associated with the sediment phase.
Mineralization and Volatilization of Polychlorinated Biphenyls in Sludge‐amended Soils
Authors: Fairbanks B. C. , O'Connor G. A. , Smith S. E.
Published: July 2010

Polychlorinated biphenyls (PCBs) are toxic organics of concern limiting the reuse of sewage sludge on agricultural lands. The mineralization and volatilization of PCBs (14C‐Aroclor 1254) were monitored for 240 d in three calcareous soils from New Mexico, amended or unamended with sewage sludge. Two first‐order rate constants were used to describe both processes and to compare treatment effects of sludge addition, PCB concentration (5, 50, 500 mg/kg), soil textural class, and length of sludge incubation with soils prior to experimentation. Total loss of PCBs ranged from 8 to 33%. Fifty and 95% disappearance times ranged from 2.5 to 5.9 yr and 6.1 to 26.3 yr, respectively. Treatment effects on total loss closely paralleled those of volatilization. Volatilization of organics ranged from 5 to 31%, and was the major means of loss of 14C in unamended soils and all 500 mg PCB/kg treatments. Volatilization, and thus environmental transport, was decreased by sludge addition. Exposure of the soil to sludge prior to experimentation had no effect on volatilization when compared to fresh sludge additions. Carbon‐14‐organic volatile loss was greater in two sandy loams than in a clay soil. Comparing PCB concentrations, volatilization was generally greatest at 50 mg/kg and least at 500 mg/kg, with comparatively smaller differences between 5 and 50 mg/kg. Degradation of 14C‐Aroclor 1254 to 14CO2 ranged from 1 to 11%. Overall, 14CO2 evolution, and thus detoxification increased with sewage sludge addition and decreased with increasing PCB concentration. Mineralization exceeded volatilization in sludge‐amended soils at 5 mg PCBs/kg. During the first 60 d of incubation, previous exposure of the soil to sewage sludge increased mineralization in the 5 and 50 mg PCB/kg treatments. In no case did sewage sludge additions increase the environmental hazard of Aroclor 1254 in these soils.
Decomposition of Fresh and Anaerobically Digested Plant Biomass in Soil
Authors: Moorhead K. K. , Graetz D. A. , Reddy K. R.
Published: July 2010

Using water hyacinth [Eichhornia crassipes (Mart.) Solms] for wastewater renovation produces biomass that must be disposed of. This biomass may be anaerobically digested to produce CH4 or added to soil directly as an amendment. In this study, fresh and anaerobically digested water hyacinth biomass, with either low or high N tissue content, were added to soil to evaluate C and N mineralization characteristics. The plant biomass was labeled with 15N before digestion. The fresh plant biomass and digested biomass sludge were freeze‐dried and ground to pass a 0.84‐mm sieve. The materials were thoroughly mixed with a Kindrick fine sand (Arenic Paleudults) at a rate of 5 g kg−1 soil and incubated for 90 d at 27 °C at a moisture content adjusted to 0.01 MPa. Decomposition was evaluated by CO2 evolution and 15N mineralization. After 90 d, approximately 20% of the added C of the digested sludges had evolved as CO2 compared to 39 and 50% of the added C of the fresh plant biomass with a low and high N content, respectively. First‐order kinetics were used to describe decomposition stages. Mineralization of organic 15N to 15NO™3‐N accounted for 8% of applied N for both digested sludges at 90 d. Nitrogen mineralization accounted for 3 and 33% of the applied organic N for fresh plant biomass with a low and high N content, respectively.
Metal Accumulation in Corn and Barley Grown on a Sludge‐amended Typic Ochraqualf
Authors: Rappaport B. D. , Martens D. C. , Reneau R. B. , Simpson T. W.
Published: July 2010

A field experiment was conducted during the 1984 and 1985 growing seasons in the Atlantic Coastal Plain region to evaluate heavy metal accumulation in corn (Zea mays L.) grain and stover and in barley silage (Hordeum vulgare L.) grown on a poorly drained, sludge‐amended soil. The study was conducted using in situ controlled lateral flow plots (1.5 by 2.3 m) on Acredale silt loam (fine‐silty, mixed, thermic, Typic Ochraqualfs) with a cation exchange capacity of 6.9 molc kg−1 and a pH of 6.6. An aerobically digested sludge from a wastewater treatment plant with major industrial inputs was applied to the plots in 1984 at rates of 0, 42, and 84 dry Mg ha−1. At the highest application rate, 1.8, 304, 17.2, and 248 kg ha−1 of Cd, Cu, Ni, and Zn were applied, respectively. Cadmium concentration was <0.01 mg kg−1 in the corn grain in both 1984 and 1985. Sludge application increased the concentration of Ni and Zn in the corn grain in 1984 and 1985. Levels of Cd and Cu were unaffected by sludge application in the corn grain for both years. Copper, Ni, and Zn levels were increased in the barley silage by sludge application. Levels of DTPA (diethylenetriaminepentaacetic acid)‐extractable metal in the Ap horizon were increased by sludge applicatioo and were 0.25, 60, 2, and 30 mg Cd, Cu, Ni, and Zn kg−1 in the highest sludge treatment, respectively. The DTPA‐extractable Cd, Cu, Ni, and Zn within the soil profile indicated no downward metal movement. On this poorly drained soil, phytotoxicity due to metals did not occur even where Cu was applied in excess of 280 kg ha−1, which is the maximum amount of Cu that could be applied to the soil based on USEPA guidelines.
Soil‐catalyzed Complexation of the Pollutant 2,6‐Diethylaniline with Syringic Acid
Authors: Liu Shu‐yen , Minard Robert D. , Bollag J. ‐M.
Published: July 2010

The catalytic capability of a soil‐water slurry has been demonstrated by the rapid and substantial formation of a hybrid dimer from the incubation of the slurry with 2,6‐diethylaniline (2,6‐DEA) and syringic acid. After a 1‐d incubation, >60% of the added chemicals were incorporated into the hybrid dimer N‐(2,6‐diethylphenyl)‐2,6‐dimethoxy‐p‐benzoquinone imine. No further increase or decrease in the concentration of the hybrid dimer was observed during the 6‐d incubation. Sterilization of the soil by γ‐irradiation decreased the yield of the hybrid dimer by 22%, and autoclaving the soil completely destroyed its catalytic ability. The persistence of the hybrid dimer was determined by incubating its radiolabeled analogue with the soil‐water slurry. The hybrid dimer was quite stable; after incubation for 45 d about 92% of the added radioactivity was recovered, of which 84% was found to be the unchanged hybrid dimer. Our results provide evidence that covalent binding of pollutants to humus constituents can occur readily and can provide a means for containing pollutants from the environment.
Revegetation and Minesoil Development of Coal Refuse Amended with Sewage Sludge and Limestone
Authors: Joost R. E. , Olsen F. J. , Jones J. H.
Published: July 2010

A study was conducted at Peabody Coal Company's Will Scarlet Mine in southern Illinois to evaluate the effectiveness of deep incorporation of dried sewage sludge and/or limestone to ameliorate acid coal refuse (gob) for establishment and survival of three forage grasses. Dried sewage sludge and/or limestone were applied at 10 rates throughout the profile of trenches opened (30 or 60 cm) by a cable trencher. Subplots of reed canarygrass (Phalaris arundinacea L.), tall fescue (Festuca arundinacea Schreb.), and redtop (Agrostis alba L.) were established in September 1980. Analysis of soil chemical and physical changes over time indicated that organic matter applied in the sewage sludge decreased by 35% 2 yr after the plots were established, while the proportion of sand‐size water‐stable aggregates increased over the same period. The proportion of large pores increased in the high rate sewage sludge plots over that of lime‐treated plots. Coal refuse pH increased from 2.7 in the unamended gob to 4.4 to 5.2 with all treatments but the two lower lime rates. All treatments maintained grass stands over 4 yr with the exception of the 225 Mg sludge ha−1 plus 45 Mg limestone ha−1 mixture at 60 cm. Reed canarygrass invaded adjacent plots and was more persistent than the other grasses. Mean herbage yield of the grasses exceeded 4.0 Mg ha−1 on all treatments. Tissue accumulation of heavy metals was not a problem. Tissue NO3 levels were considered toxic for ruminants the first 3 yr, but decreased significantly over time. Coal refuse disposal sites can be revegetated without the use of soil cover by application of sewage sludge or limestone.
Residual Pesticide Concentrations in Bear Creek, Mississippi, 1976 to 1979
Authors: Cooper C. M. , Dendy F. E. , Mc Henry J. R. , Ritchie J. C.
Published: July 2010

Concentrations of DDT [1,1,1‐trichloro‐2,2‐bis(p‐chlorophenyl)‐ ethane], DDE [1,1‐dichloro‐2,2‐bis(p‐chlorophenyl)‐ethylene], DDD [1,1‐dichloro‐2,2‐bis(p‐chlorophenyl)‐ethane], and toxaphene (chlorinated camphene) were measured in surface waters, soils, storm runoff, and deposited bottom sediments along the 83‐km length of Bear Creek. This creek is a Mississippi River alluvial stream, which includes six riverine lakes in an intensively cultivated 44 260‐ha watershed. Low concentrations of pesticides were persistent in surface waters of the creek from the headwaters to the confluence with the Yazoo River with no significant differences in concentrations between sites on the creek or in isolated offstream lakes. Pesticide concentrations increased during periods of maximum runoff, which corresponded with the winter rainy season and minimum vegetative cover on the soil. Seven years after spraying had ceased, DDT was still available to surface waters and aquatic biota by way of eroded soil from farm fields and from deposited sediments in stream and lake bottoms. No significant declines in concentrations of DDT in surface waters were found in comparisons with two earlier studies nor were any declines in surface water contamination noted during this 3‐yr study.
Swine Manure and Lagoon Effluent Applied to a Temperate Forage Mixture: I. Persistence, Yield, Quality, and Elemental Removal
Authors: Burns J. C. , Westerman P. W. , King L. D. , Overcash M. R. , Cummings G. A.
Published: July 2010

Swine (Sus scrofa domesticus) waste can be a nutrient source for crops when applied as a manure slurry or lagoon effluent. Limited land area for disposal may result in high application rates. Yet rates must be controlled to ensure stand persistence if perennial crops are grown and if groundwater quality (NO3 concentrations) are to be considered. Also, safe concentration of elements in the resulting forage must be assured if used for animal feed. A 4‐yr study was conducted to determine the effect of applying swine waste as manure slurry or lagoon effluent on persistence of a temperate forage mixture of predominantly tall fescue (Festuca arundinacea Schreb.). Treatments were: a commercial N‐P‐K fertilizer (F), consisting of 201 kg N ha−1 yr−1 (67 kg ha−1 in three applications) and 34 and 65 kg ha−1 of P and K, respectively; 670 kg of N ha−1 yr− as a swine manure slurry (M); and supplying approximately 600 (E1) and 1200 (E2) kg of N ha−1 from swine lagoon effluent. Subtropical grasses invaded all treatments by the third year but the E2 treatment had greatest infestation averaging 53% of the dry matter and tall fescue averaging only 39%. Dry matter yields were similar between F and M treatments averaging 7750 kg ha−1 yr−1 while applying N as effluent (E1) increased yields 3430 kg ha−1 above M. Doubling the N loading rate (E2 vs. E1) did not increase yields (P ≤0.05). Concentrations of the 11 elements analyzed (N, P, K, Ca, Mg, Cl, Mn, Cu, Zn, Fe, and Na) showed a treatment × year interaction. Forage Zn was consistently increased by M treatment compared with F or E1 treatments and forage Cu was elevated by M treatment the last 2 yr of the study. In vitro dry matter disappearance was similar (670–685 g kg−1) among all treatments, but forage NO3‐N concentration from the E1 and E2 treatments, and after the second year for the M treatment, was considered unsafe for ruminants (> 700 mg NO3‐N kg−1). The M, E1, and E2 treatments added large quantities of elements (N, P, K, Ca, Na, and Cl) that were not removed in the forage.
Cadmium Levels in Soils and Plants From Some Long‐term Soil Fertility Experiments in the United States of America
Authors: Mortvedt J. J.
Published: July 2010

Phosphate fertilizers contain varying amounts of Cd and other heavy metals as contaminants from phosphate rock (PR). To determine whether periodic applications of P fertilizers resulted in measurable accumulations of Cd in soils and in harvested crops, soil and plant tissue samples from nine long‐term (> 50 yr) soil fertility experiments in the USA were analyzed for Cd, as well as P and other elements. Annual Cd rates were estimated to range from 0.3 to 1.2 g ha−1 in these experiments. Plant tissues analyzed were corn (Zea mays L.), soybean (Glycine max L. Merr.), and wheat (Triticum aestivum L.) leaves or grain, and timothy (Phleum pratense L.) forage. Results from these long‐term experiments have shown that plant uptake of Cd contaminants in P fertilizers containing < 10 mg Cd kg−1 is negligible. While the Cd accumulations in soil in these experiments could not be calculated, they would approximate that accumulated in most agricultural soils in the USA at this time. About 70% of the P fertilizers is produced from Florida PR, which contains < 10 mg kg−1 of Cd, as compared with about 10% from the western USA, which contains higher Cd levels. Therefore, adding Cd to soils as a contaminant in P fertilizers at rates ranging from 0.3 to 1.2 g Cd ha−1 does not appear to result in increased Cd levels in plants as a result of long‐term P fertilization.
Availability and Plant Uptake of Trace Elements from Recarbonated Retorted Shale
Authors: Reddy K. J. , Lindsay W. L.
Published: July 2010

One solution to the management of retorted shale (spent oil shale) is to establish a satisfactory vegetative cover over retorted shale disposal piles. However, the high alkalinity of these waste materials severely hampers direct revegetation efforts. A sample of Lurgi‐Ruhrgas (Lurgi) retorted shale was recarbonated to lower its high alkalinity, by exposing it to 0.04 MPa CO2(g) and moisture for 4 d. A preliminary greenhouse experiment was conducted to examine the uptake of microelements by tall wheatgrass [Agropyron elongatum (Host) Beauv.] grown on this recarbonated shale. Exposing spent Lurgi shale to pressurized CO2(g) and moisture lowered the pH from 11.6 to 8.6 and increased the electrical conductivity (EC) from 4.7 to 15.8 dS/m. Lowering the pH through recarbonation increased ammonium bicarbonate‐diethylenetriaminepentaacetic acid (AB‐DTPA) extractable Fe, Zn, Cu, Mo, and Ni, while extractable B, Sr, Cr, and Mn were decreased. Wheatgrass seeds failed to germinate in spent Lurgi shale, which had no soil cover. Plant growth decreased in the recarbonated shale compared to retorted shale with a soil cover due to higher salinity. Plant tissue grown on the recarbonated shale accumulated lower concentrations of As, Se, Ba, Cd, Sr, and Ti than did plants grown on spent Lurgi shale with a soil cover. Boron concentrations ranged from 7.2 to 13.0 mg/kg in plant tissue, with the lowest concentrations coming from the recarbonated shale. Fluoride concentrations in plant tissue increased with recarbonation but were below the toxic level. Plant uptake of Mo increased with recarbonation. The Cu/Mo ratios of the tall wheatgrass were below 2:1 in all treatments except the control. This preliminary study shows that recarbonated spent shales can be revegetated directly without a soil cover but that some leaching may be advantageous.
Strontium‐90 in Food and Bone From Fallout
Authors: Klusek C. S.
Published: July 2010

The long‐term, continuing study of fallout 90Sr in humans and the environment has provided basic information that is required to assess human exposure from 90Sr from nuclear tests. The current stratospheric inventory of 90Sr is very low and the rate of new input into the environment is exceeded by the rate of decay. However, because of its long physical and biological half‐life, 90Sr continues to be one of the most persistent artificial radionuclides that reaches humans through ingestion. Quarterly sampling of 19 representative food items in New York and San Francisco since 1954 provides a record of the changes that occur in the relative contributions of 90Sr by the various food categories, as well as the changes in the total 90Sr intake to the diet in these typical Northern Hemisphere regions. The current intake of 0.18 Bq/d in New York has declined from maximum levels of 1.1 Bq/d in 1963 to 1964. The 90Sr content of San Francisco diets has been consistently lower than the New York level. The retention of dietary intake has been studied through the analysis of bone samples from long‐term residents of the same cities. The measured concentration of 90Sr in adult bones in the USA is now 50% less than the peak concentrations of 85 Bq/kg Ca seen in 1965.
Long‐term Sludge Applications on Cadmium and Zinc Accumulation in Swiss Chard and Radish
Authors: Chang A. C. , Page A. L. , Warneke J. E.
Published: July 2010

Swiss chard (Beta vulgare var. Fordhook) and radish (Raphanus sativus var. Cherry Belle) were grown twice annually (spring and fall) on a Ramona sandy loam (fine‐loamy, mixed thermic, Typic Haploxeralfs) soil treated with 0, 22.5, 45, 90, and 180 Mg ha−1 yr−1 of composted sludges from Los Angeles. The soil received two sludge inputs of equal amounts each year and crops were planted shortly after each sludge incorporation. Cadmium and Zn accumulation of the plant tissue from 1976 to 1985 was examined. Results from the analysis of variance indicated that effects due to sludge application rates, seasons plants were grown, number of years of sludge application, and their interactions were all significant. If the data sets were partitioned according to sludge application rates and seasons, metal concentrations of the plant tissue may be expressed as a nonlinear regression model, y = a + b (1 − e−cx), where y is the metal concentration of the plant tissue, x is the cumulative sludge loading, and a, b, and c are constants. All but two nonlinear regressions were significant at p <0.05 with R2 from 0.38 to 0.95. The deviation of the observed values from the predictions of the regression model indicated that other factors might have also affected the metal uptake by plants. Stepwise multiple regression analysis of the partitioned data sets indicated that soil pH, soil salinity, soil temperature, and length of growing season influenced the metal accumulation in plant tissue.
Effect of Calcium Magnesium Acetate on Heavy Metal Mobility in Soils
Authors: Elliott H. A. , Linn J. H.
Published: July 2010

Calcium magnesium acetate (CMA) is a promising replacement for traditional roadway deicing salts. Prepared in a 3:7 Ca/Mg molar ratio, CMA was studied to assess its impact on the mobility of metals in contaminated soils. In batch soil suspensions (pH 3–7), 0.01 and 0.1 M CMA solutions substantially enhanced Zn and Cu desorption from a metal‐enriched soil. In soil columns leached with acidified (pH 4) 0.01 M CaCl2, a thin layer of CMA initially increased metal efflux. Preferential adsorption of Ca2+ and Mg2+ at exchange sites (i) displaced bound metal ions into solution and (ii) desorbed H+, which promoted dissolution of metal‐containing solid phases. This was counteracted by the pH neutralizing effect of acetate ions, so that within 10 pore volume displacements, the presence of CMA resulted in a net suppression of leachate metal levels. In pH‐controlled batch experiments, metal solubilization was not significantly different between equimolar amounts of CMA and the Cl− or NO−3 salts. Thus, under the experimental conditions, acetate complexation played a minor role in metal mobilization. Highway deicing with CMA may temporarily increase translocation of metals in strongly buffered acid roadside soils. Input of acetate ions and an increase in exchangeable bases with sustained CMA use should render northeastern USA soils less vulnerable to acidification, thereby inhibiting conditions that promote metal solubilization.
Changes in Litter Near an Aluminum Reduction Plant
Authors: Beyer W. Nelson , Fleming W. James , Swineford Douglas
Published: July 2010

Litter was collected from eight sites at distances as far as 33 km from an Al reduction plant in western Tennessee. As a result of an accumulation of fine litter (<4.75 mm) the weight of the litter per unit area was abnormally high at the two sites within 2 km of the plant. Compared to litter collected far from the plant, it had a lower fiber content, was more sapric, and was less acid. Fluoride emissions from the plant were suggested as the probable cause of litter changes. Concentrations of water‐extractable and acid‐extractable F− in the litter, the 0‐ to 5‐cm soil layer, and the 5‐ to 15‐cm soil layer were strongly correlated with distance from the plant. Total acid‐extractable F− in the litter and upper 15 cm of soil was about 41 times as much at the closest site (700 mg/kg) as at the most distant sites (12 and 16 mg/kg). In a bioassay of litter from our study sites, woodlice (Porcellio scaber Latr.) had an abnormally high mortality in litter that contained 440 mg/kg or more of acid‐extractable F−. However, when F− was added as NaF to litter, a significant increase in mortality was observed only in treatments exceeding 800 mg/kg. The decrease in the rate of decomposition of the litter might eventually induce a deficiency of soil macronutrients, but none was detected.
Effects of Long‐Term 2,4‐D Field Applications on Soil Biochemical Processes
Authors: Biederbeck V. O. , Campbell C. A. , Smith A. E.
Published: July 2010

The effects of annual applications of 2,4‐D (2,4‐dichlorophenoxyacetic acid) on the soil biosphere were studied. Plots established on a Udic Boroll at Indian Head, Saskatchewan, that have received 2,4‐D amine or ester, at rates of 1.12 kg ha−1 for 35 consecutive years were sampled over a 9‐month period to determine the effect of the herbicide on some biochemical activities related to soil fertility. Treated and control plots of stubble‐seeded wheat (Triticum aestivum L.) were sampled just before and at 2 and 16 weeks after the annual 2,4‐D application to determine temporary and long‐term herbicide effects. In the top 2.5 cm of soil (the prime site of 2,4‐D deposition), biomass, N mineralization rate, and potentially mineralizable N (No) were not affected by the amine or ester, but urease was temporarily depressed by both formulations. Nitrification and activity of phosphatases were reduced temporarily by the ester formulation. Dehydrogenase activity was depressed weakly but persistently by the ester formulation. Respiration was enhanced temporarily after amine application. There was a distinct tendency for the ester to exert a more depressive effect than the amine formulation on the measured variables. Although some herbicide‐induced changes were significant (P <0.05), all depressive and stimulatory effects detected were relatively small (<35% change from control) and most were short‐lived. The results were interpreted by comparing the duration and magnitude of the biochemical stress caused by the herbicide with stresses induced by naturally occurring adversities. From these comparisons we concluded that the effects of long‐term 2,4‐D applications were neither ecologically significant nor did they interfere with nutrient cycling to adversely affect soil fertility.