bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selenium Immobilization in a Pond Sediment at Kesterson Reservoir
Authors: Long Robert H. B. , Benson Sally M. , Tokunaga Tetsu K. , Yee Andrew 
Published: July 2010

AbstractKesterson Reservoir, Merced County, CA, a disposal facility for agricultural drain water, became the object of intense scientific investigation following discovery in 1983 that Se‐laden agricultural drain water was having serious effects on the reproductive success of waterfowl. A remedial measure involving permanent flooding with low‐Se water, aimed at taking advantage of low Se solubility under reducing conditions, was proposed as a means of limiting Se movement into groundwater and biota. A field experiment was undertaken to evaluate the feasibility of the proposed remedial measure, its impact on the quality of shallow groundwater and for quantifying Se immobilization and transport through a newly flooded pond bottom soil. Extensive soil water and groundwater sampling demonstrated that although initial soluble Se concentrations in the top 1.22 m (4 ft) of soil typically ranged from approximately 1000 to 3000 µg L−1, Se concentrations declined dramatically after flooding and elevated concentrations below 1.22 m were observed at only one of five sampling sites. Analysis of the temporal and spatial changes in the distribution of dissolved Se and Cl− indicated that 66 to 108% of the initial soluble Se present in the top 1.22 m was immobilized shortly after flooding. These estimates were consistent with the low Se concentrations observed in shallow monitoring wells. The extent to which Se immobilization occurred correlated inversely with average pore water velocity. Data presented suggest that reducing conditions in the newly flooded soils lead to the microbially mediated transformation of selenate to less soluble or mobile forms.
Metal Content of Fungal Sporocarps from Urban, Rural, and Sludge‐Treated Sites
Authors: Zabowski D. , Zasoski R. J. , Littke W. , Ammirati J. 
Published: July 2010

AbstractFungal sporocarps can influence metal cycling by the uptake of trace metals, which are then readily available for consumption and incorporation into higher food chain levels. This study was conducted to determine if increased sporocarp metal concentrations occurred relative to substrate metal availability in rural, urban, smelter impacted or municipal sewage sludge‐treated sites. Fungal fruiting bodies were collected from rural forests, from urban forests receiving point‐source metal pollution and from forests that had been treated with municipal sewage sludge. Metal concentrations in fungal sporocarps were found to be significantly higher on sewage sludge‐treated sites when all species were considered. Smelter pollution and serpentinite soil, however, were also found to elevate some metals to levels similar to those found at sludge‐amended areas. Overall, individual species appear to be the most important factor for predicting metal uptake from impacted soils and possible inclusion into food chains.
Dissolved and Suspended Solids Transport from Coastal Plain Watersheds
Authors: Hubbard R. K. , Sheridan J. M. , Marti L. R. 
Published: July 2010

AbstractExcessive amounts of dissolved or suspended solids in surface runoff or base flow may degrade the quality of streams, lakes, or other water bodies. Loads of dissolved and suspended solids in streamflow reflect the quality of water entering via surface runoff or base flow. This study was conducted to determine the concentrations and loads of dissolved and suspended solids in Coastal Plain streamflow; to examine relationships between concentrations, loads, and flow rate; and to determine overall streamflow water quality for these parameters. Dissolved solids and suspended sediment concentrations were determined on weekly or high‐flow storm event streamflow samples collected at gaging stations on three subwatersheds (B, 334.3 km2; F, 114.9 km2; and K, 16.7 km2) of the Little River Watersheds located near Tifton, GA. Dissolved solids concentrations ranged from 19 to 159 mg L−1, and generally decreased as per unit area instantaneous discharge rate increased. Suspended sediment concentrations ranged from 1 to 137 mg L−1, and generally increased as per unit area instantaneous discharge rate increased. Regression analyses showed good relations between log transforms of both dissolved solids load (r2 = 0.97) and suspended sediment load (r2 = 0.79), vs. total monthly runoff. Mean suspended sediment concentrations during high‐flow events were greater than means from the overall data set, while mean concentrations of dissolved solids from these events were reduced relative to the overall data set. The study showed that dissolved solids are the major component of total solids in Coastal Plain streamflow. The mean dissolved and suspended sediment concentrations during the study were 67, 60, and 51 mg L−1; and 14, 17, and 14 mg L−1 for Watersheds B, F, and K, respectively. Overall, the study showed that, as measured on these watersheds, Coastal Plain streamflow is of good quality in terms of both dissolved and suspended solids. This good quality may reflect land‐use practices designed to prevent soil erosion, but primarily reflects the Coastal Plain landform shape, which causes sediments eroded from the uplands to be deposited in the riparian zone before they can enter streamflow.
Leaching of Radionuclides from Decaying Blueberry Leaves: Relative Rate Independent of Concentration
Authors: Sheppard S. C. , Evenden W. G. 
Published: July 2010

AbstractLeaching of radionuclides from decaying vegetation has not been extensively investigated, especially for radionuclides other than 137Cs. We obtained leaves of blueberry (Vaccinium angustifolium × V. corymbosum) that contained over 25‐fold ranges in Se, Cs, and I concentrations, as well as a small quantity of leaves containing detectable U. All were contaminated by way of root uptake. Leaching took place for a period of 1 yr in the laboratory, using leach water from forest litter. Monthly, measurements were made of the radionuclide contents and decaying leaf dry weights. The data conformed to an exponential decay model with two first‐order components. In no case did the relative loss rates vary systematically with the initial tissue radionuclide concentrations. Loss rates decreased in the order Cs > I > U > dry wt. > Se. Because of the low leaching rate of Se relative to the loss of dry weight, decaying litter may actually accumulate elements such as Se. Accumulation of radionuclides in litter could have important implications for lateral transport, recycling, and direct incorporation into edible mushrooms.
Plant Uptake and Cycling of Trace Elements on Retorted Oil Shale Disposal Piles
Authors: Stark John. M. , Redente Edward F. 
Published: July 2010

AbstractThis study considers some of the environmental hazards posed by high trace element concentrations in plants growing on retorted oil shale disposal piles and the potential for surface accumulation of trace elements via biocycling. Arsenic, B, Cu, F, Mo, and Se concentrations in plants growing on six disposal piles were determined 7 yr following site construction. Disposal treatments consisted of leaving Paraho retorted shale exposed at the surface, leaching exposed retorted shale with 760 mm of water, covering retorted shale with 30, 60, or 90 cm of soil, or a 30‐cm rock capillary barrier and 60 cm of soil. These treatments plus a disturbed soil reference plot (no retorted shale) were seeded in 1977 with three mixtures of native and introduced plant species. In 1983, Mo was present in plants at high enough levels to cause molybdenosis in ruminants. Molybdenum, F, As, and Se concentrations in plants decreased as depth of replaced topsoil increased. Leaching only slightly reduced concentrations in plants. Capillary barrier and 90‐cm treatments were the most effective at reducing plant trace elements concentrations; however, shrubs and legumes from these treatments still occasionally had higher trace element contents than plants growing on disturbed soil reference plots. Legumes had higher concentrations of most trace elements than grasses or shrubs. For this reason species composition had a major effect on total trace element content of stands of vegetation. Rates of movement to the surface via biocycling appear to be relatively slow, although they may continue to increase in the future.
Pendimethalin Volatility following Application to Turfgrass
Authors: Cooper R. J. , Jenkins J. J. , Curtis A. S. 
Published: July 2010

AbstractVolatilization can be a significant avenue of loss for some pesticides following application to field crops or soil. Volatility following pesticide application to dense turfgrass, however, has not been well documented. This work characterized volatilization of the preemergence herbicide pendimethalin [N‐(1‐ethylpropyl)‐3,4‐dimethyl‐2,6‐dinitrobenzenamine] following application to a Kentucky bluegrass (Poa pratensis L.) turf. Pendimethalin [60% water dispersible granules (WDG)] was applied at 3.4 kg ha−1 with volatilization losses monitored over a period of 15 d. Pendimethalin vapor flux followed a diurnal pattern with maximum daily flux usually occurring 1300 to 1500 h. Maximum flux of airborne residues occurred 1300 to 1500 h. Maximum flux of airborne residues occurred 1300 to 1500 h on the day of application when losses totaled 23.6 g ha−1 h−1. Pendimethalin volatile losses were 4.8% (165 g ha−1) of the original application during the first 24 h following application. Overnight (1900 to 0700 h) volatile losses measured 9.5 and 10.5 g ha−1 on Days 1 and 2 of the experiment (each overnight loss approximately 0.3% of application). Volatile losses during the 48 h following application totaled 6.1%, with an estimated loss of approximately 13% during the 5‐d period following application. Daily volatile loss declined in a diphasic manner over the course of the study, with an initial period of rapid decline in daily vapor flux lasting 5 to 7 d followed by a period of slower decline for the remainder of the study. Dissipation of foliar dislodgeable residues followed a diphasic decline similar to that observed for daily airborne loss, suggesting a relationship between pendimethalin volatilization and foliar dislodgeable residues over time.
Assessment of Management Practices for Reducing Pesticide Runoff from Sloping Cropland in Illinois
Authors: Felsot Allan S. , Mitchell J. Kent , Kenimer Ann L. 
Published: July 2010

AbstractThe influence of tillage system and contouring practice on runoff of soil‐applied alachlor [2‐chloro‐2′,6′‐diethyl‐N‐(methoxymethyl)acetanilide], carbofuran (2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl methylcarbamate), and terbufos (S‐[(tert‐butylthio)methyl] O,O‐diethyl phosphorodithioate) from small plots (30 m2) were studied using a rainfall simulator. Plots were planted in corn (Zea mays L.) in 1983, soybean [Glycine max (L.) Merr.] in 1984, and corn in 1985. Runoff was measured during a 60‐min event with a rainfall intensity of 63 mm/h. During 1984, moldboard‐plowed and no‐till systems were studied with rows oriented on the contour or up‐and‐down slope (7–11% slope). Compared to moldboard plow, up‐and‐down slope no‐till and contouring significantly reduced runoff of carbofuran and alachlor. Percentage of applied carbofuran lost in runoff and sediment ranged from 1% (contoured moldboard) to 11% (up‐and‐down slope moldboard). Percentage of applied alachlor lost ranged from 1% (contoured no‐till) to 2% (contoured moldboard). During 1985, the effects of row orientation were evaluated on moldboard‐plow, chisel‐plow, ridge‐till, strip‐till, and no‐till systems. Under up‐and‐down slope conditions, runoff of alachlor and terbufos plus two metabolites (terbufos sulfoxide and terbufos sulfone) was significantly reduced by strip‐till (<1% loss) compared to moldboard‐plow (6% loss). Larger losses of alachlor (2% of applied) from up‐and‐down slope no‐till than from the other conservation tillage systems (1% or less) was attributed to high concentrations in runoff associated with extensive washoff of the herbicide from soybean crop residues. With contouring, ridge tillage also was effective in reducing pesticide runoff (<1% of applied pesticide), and strip‐till held losses to <0.1%. Alachlor and carboforan were translocated from plots largely in moving water, but terbufos and metabolites were recovered mainly in eroded sediment. Although, no conservation tillage system completely eliminated pesticide runoff, losses were most effectively minimized by contoured strip‐till and no‐till, which controlled both water and sediment movement.
Microbial Release of 2,4‐Dichlorophenol Bound to Humic Acid or Incorporated during Humification
Authors: Dec J. , Shuttleworth K. L. , Bollag J.‐M. 
Published: July 2010

AbstractThe microbial release of 14C‐labeled 2,4‐dichiorophenol (DCP) bound to synthetic and natural humic materials or polymerized by enzymes was investigated to evaluate the possibility of future adverse effects if binding or polymerization is used for decontamination purposes. After 12 wk of incubation with microorganisms obtained from a forest soil, the amounts of substances released into the media were very small (maximum 2.2% of the initially bound 14C) without regard to the kind of the polymer into which 14C‐DCP was incorporated. Most of the radioactivity (46.2 to 80.8%) remained bound to the precipitated humic materials or in the DCP‐po!ymer (90.1 to 97.0%). Certain amounts of the released substances evolved in the form of 14CO2 (1.0 to 9.4% from humic materials and 0 to 0.5% from a DCP‐polymer). The rate of mineralization differed depending on the type of DCP binding—surface‐bound or incorporated during synthesis of humic acid—and on the kind of polymer to which 14C‐DCP was attached. The release into the media and 14CO2 evolution for synthetic and natural humic acids was essentially the same. When only DCP was present in the growth medium, the formation of 14CO2 was less than from a DCP‐humic acid complex; this may indicate that 14CO2 from a DCP‐humic acid complex originated mostly from DCP derivatives. The data obtained for DCP did not provide any evidence for a delayed pollution problem associated with polymerization or binding of xenobiotics to humic acids.
Effect of Municipal Sewage Sludge Application on Growth of Two Reclamation Shrub Species in Copper Mine Spoils
Authors: Sabey B. R. , Pendleton R. L. , Webb B. L. 
Published: July 2010

AbstractOne‐year old transplants of fourwing saltbush [Atriplex canescens (Pursh) Nutt.] and mountain big sagebrush [Artemisia tridentata ssp. vaseyana (Rybd.) Beetle] were grown for 9 mo in large greenhouse pots containing copper mine spoil material amended with one of three rates of municipal sewage sludge. Sludge was thoroughly mixed with the soils in some pots and concentrated around the root plug in others. Additionally, some pots were seeded with western wheatgrass (Agropyron smithii Rydb.) to determine whether the presence of grasses would affect shrub response to sludge addition in low pH copper mine spoils. Growth of fourwing saltbush was enhanced from 38‐ to over 300‐fold by the addition of sewage sludge. Growth of big sagebrush was increased over six‐fold. This was likely the result of increased N, P, and K availability, although improved biological and physical properties of the spoil‐sludge mix may also have been factors. The addition of western wheatgrass to pots containing fourwing saltbush caused a decrease in shrub growth, undoubtedly due to competition for nutrients and other plant growth factors. At the conclusion of the study, shrub leaves contained high levels of Cd and Pb, reflecting the high Cd and Pb content of the growth medium. Zinc, Cu, Mn, and Fe levels were also largely higher than are typical for plant tissue. Shrubs grown in pots in which sludge additions were concentrated around the root plug accumulated more heavy metal than did mixed treatments. Grass tissue did not accumulate excessively high quantities of heavy metals, with the exception of Cu.
Plant Uptake of Pentachlorophenol from Sludge‐Amended Soils
Authors: Bellin Cheryl A. , O'Connor George A. 
Published: July 2010

AbstractA greenhouse study was conducted to determine the effects of sludge on plant uptake of 14C‐pentachlorophenol (PCP). Plants included tall fescue (Festuca arundinacea Schreb.), lettuce (Latuca sativa L.), carrot (Daucus carota L.), and chile pepper (Capsicum annum L.). Minimal intact PCP was detected in the fescue and lettuce by gas chromatography/mass spectrometry (GC/MS) analysis. No intact PCP was detected in the carrot tissue extracts. Chile pepper was not analyzed for intact PCP because methylene chloride extracts contained minimal 14C. The GC/MS analysis of soil extracts at harvest suggests a half‐life of PCP of about 10 d independent of sludge rate or PCP loading rate. Rapid degradation of PCP in the soil apparently limited PCP availability to the plant. Bioconcentration factors (dry plant wt./initial soil PCP concentration) based on intact PCP were <0.01 for all crops, suggesting little PCP uptake. Thus, food‐chain crop PCP uptake in these alkaline soils should not limit land application of sludge.
Soil Denitrification Rates in Four Subalpine Plant Communities of the Sierra Nevada
Authors: Hixson S. E. , Walker R. F. , Skau C. M. 
Published: July 2010

AbstractThe acetylene inhibition method was used to determine soil denitrification rates of a riparian, meadow, forest, and barren site in the eastern Sierra Nevada. Data were collected from these four sub‐alpine plant communities during dawn‐to‐dusk measurement periods in June, August, and October in order to examine denitrification during the dry season. Soil temperature, moisture, organic matter, C, N, C/N ratio, NO3‐N, and pH were measured to assess their effects on denitrification rates. At all sites, denitrification rates varied randomly during each measurement period and were not influenced by variation in any other soil parameter investigated. Comparisons among the four communities revealed that no single site consistently exhibited the highest or lowest denitrification rate throughout the study. Denitrification rates and soil temperatures in the riparian, meadow, and forest communities declined concurrently during the October measurement period relative to those measured in June and August. Declining denitrification rates from June through October paralleled a decrease in soil organic matter in the riparian community, and denitrification rate varied with soil N over the three measurement periods at the barren site. These results suggest that denitrification in wildland soils varies both temporally and spatially, and that soil physical and chemical parameters identified here as influencing this process explain long‐term but not short‐term variations in denitrification rates.
Nitrogen Mineralization and Elemental Availability in Soils Amended with Cocomposted Sewage Sludge
Authors: Sims J. T. 
Published: July 2010

AbstractLand application of cocomposted sewage sludge (CCSS), produced by the aerobic digestion of municipal refuse and anaerobically digested sewage sludge, represents an alternative use for organic wastes that are currently landfilled, incinerated, or disposed of by ocean dumping. Laboratory and greenhouse studies were conducted with four types of CCSS to determine their suitability for agricultural use, based on mineralizable N and the availability of plant nutrients and certain nonessential heavy metals (Cd, Cr, Ni, Pb). Nitrogen mineralization studies, conducted for 20 wk with three soils amended with 22 Mg/ha of each CCSS type (total N added = 250 to 398 kg N/ha), indicated that immobilization of N could be a serious problem with these composts. Negative values, ranging from −7 to −39 mg/kg, were obtained for net N mineralization (N mineralized adjusted for inorganic N added in the CCSS and mineralized soil N). Additionally, wheat (Triticum aestivum L.) plants grown in the greenhouse for 8 wk with the same CCSS applied at rates of 0, 11, 22, and 44 Mg/ha, and supplemented with 100 mg/kg of N as NH4NO3, exhibited N deficiency symptoms, reduced dry matter production, and lower plant N concentrations. Only slight differences in plant and soil (Mehlich I‐extractable) concentrations of P, K, Ca, Mg, Cu, Cd, Cr, Ni, and Pb were noted among CCSS types in the greenhouse study. The CCSS rate also had little influence on plant and soil concentrations of these elements. Soil pH, however, was increased by a lime‐amended CCSS, resulting in significant decreases in plant concentrations of Mn nd Zn. In summary, results from laboratory and greenhouse studies suggest that, when applied at agronomic rates, these composts can produce satisfactory plant growth, if adequate amounts of supplemental N fertilizers are applied, and that increases in soil and plant concentrations of nonessential heavy metals should not be a limiting factor in compost use.
Productivity of Clay Tailings from Phosphate Mining: II. Forage Crops
Authors: Mislevy P. , Blue W. G. , Roessler C. E. 
Published: July 2010

AbstractPhosphate mining in Florida produces phosphatic clay and quartz‐sand tailings waste products. Presently there are about 41 000 ha of phosphatic clay (slime ponds) in Florida. These clays contain no phytotoxic materials, are high in most plant nutrients, and average about 460 g moisture kg−1. A split‐plot field experiment was conducted to study forage yield, quality, plant nutrient concentrations, changes in soil nutrients, and 226Ra contents of 12 grass‐N source treatments. The treatment combinations (i) bahiagrass (Paspalum notatum Fluegge var. saurae Parodi ‘Pensacola’) + N, (ii) bahiagrass + white clover (WC) (Trifolium repens L. ‘Arcadia’), (iii) stargrass (Cynodon nlemfuensis Vanderyst var. nlemfuensis ‘Florico’) + N, (iv) Florico stargrass + WC, (v) Florico stargrass + alfalfa (Medicago sativa L. ‘Florida 77’), (vi) Florico stargrass + carpon desmodium (Desmodium heterocarpon (L.) D.C. ‘Florida’), (vii) Limpograss [Hemarthria altissima (Poir) Stapf et. C.E. Hubb. ‘Floralta’] + N, (viii) Limpograss + WC, (ix) Stargrass (C. nlemfuensis Vanderyst var. nlemfuensis ‘Florona’) + N., (x) Florona stargrass + WC, (xi) Florona stargrass + red clover (Trifolium pratense L. ‘Nolins’), and (xii) Florona stargrass + alfalfa, were grown on dry phosphatic clay with and without a 50 mm surface layer of quartz‐sand tailings. Nitrogen (500 kg ha−1 yr−1) was the only fertilizer element applied on grasses. No fertilizer was applied on legumes during the 4‐yr period. Results indicated that Floralta hemarthria + N, Florona stargrass + N, and Florona stargrass + alfalfa produced highest dry‐forage yields averaging 20.8, 18.1, and 17.7 Mg ha−1. Florico stargrass + WC and Floralta hemarthria + WC had annual averages of 233 and 211 g CP kg−1 and 769 and 751 g IVOMD kg−1, respectively. Grass + N treatments were about 5 to 10 percentage units lower in CP than grass + legumes. Forage mineral concentrations for P, K, Ca, Mg, Mn, Cu, Zn, and Fe, ranged from 1.3 to 39 times higher than required for growing and finishing cattle (Bos sp.). Mehlich I‐extractable soil P (1650 mg kg−1), Ca (4588 mg kg−1), and Mg (1130 mg kg−1) were very high and changed little after 4 yr of forage production. Forages had a differential uptake of 226Ra with Florona stargrass + N (1.28 pCi g−1) having the highest uptake and Pensacola bahiagrass + N (0.32 pCi g−1) having the lowest uptake. Radium 226 in the phosphatic clay was 22 pCi g−1, which was 80 times higher than levels in an unmined Spodosol; however, plant uptake was three times higher than plants grown on unmined soil. Data indicated that phosphatic clays are a fertile resource that can be used for forage production.