bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Trace Elements and Pesticides on Dephosphorylation of RNA and DNA Added to Soils
Authors: Frankenberger W. T. , Johanson J. B. , Lund L. J. 
Published: July 2010

AbstractNucleic acids are rapidly degraded in soil releasing purine and pyrimidine bases and orthophosphate (Pi). This study was carried out to assess the effects of 14 trace elements, 12 herbicides, and two fungicides on dephosphorylation of yeast ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) added to soils (Xerollic Calciorthids and Typic Haploxeralfs). The cumulative amount of Pi released from nucleic acids increased linearly with time of incubation (up to 72 h), decreased with profile depth, and was highly influenced by soil pH. When trace elements were applied and compared by using 2.5 mmol kg−1 of soil, the average inhibition in dephosphorylation of RNA and DNA in two soils ranged from 17% with Co(II) to 52% with Cu(II). The most effective inhibitors of nucleic acid dephosphorylation were Ag(I), Cu(I), Cd(II), Cu(II), Mn(II), Ni(II), and Pb(II) (avg inhibition ≥ 35%). Other elements that inhibited dephosphorylation of RNA and DNA added to soils included Ba(II), Co(II), Hg(II), Zn(II), Ti(IV), V(IV), and W(VI). When the pesticides were compared by using 5 mg of active ingredient kg−1 of soil, the average inhibition in nucleic acid dephosphorylation ranged from 14% with butylate to 39% with chloramben. The most effective inhibitors (> 25%) were atrazine, naptalam, chloramben, dicamba, trifluralin, and maneb. Other pesticides that inhibited RNA and DNA dephosphorylation in soils included cyanazine, 2,4‐D, dinitroamine, EPTC plus R‐25788, alachlor, paraquat, butylate, and captan.
Solubility Relationships and Mineral Transformations Associated with Recarbonation of Retorted Shales
Authors: Reddy K. J. , Lindsay W. L. , Boyle F. W. , Redente E. F. 
Published: July 2010

AbstractOil shales are heated at high temperatures to obtain oil. During this process carbonate minerals are destroyed by driving off CO2(g) and large amounts of waste materials (retorted shale) are produced. The pH of such retorted shales often approaches 12.0. With time, the pH of these materials will drop by attaining equilibrium with calcite (CaCO3) and atmospheric carbon dioxide (recarbonation). The objective of this paper was to examine solubility relationships and mineral transformations associated with recarbonation of retorted shales. Carbon dioxide gas (CO2[g]) was bubbled through two shale samples, one retorted by Los Alamos National Laboratory (LANL) and another retorted by Lurgi Ruhrgas (Lurgi) to lower their pH. X‐ray diffraction analysis was used to identify different mineral phases of retorted and recarbonated shales. The results show that recarbonation caused silicate minerals to dissolve, CaCO3 to precipitate, and lowered pH from approximately 12.0 to 8.0. Solubility measurements showed that upon recarbonation Ca2+ activity for both shales approached equilibrium with CaCO3 and measured CO2(g). Initially Mg2+ activity appeared to be in equilibrium with either diopside (CaMg[SiO3]2) or antigorite (Mg2.825Si2O5(OH)3.65) and measured silica, but not with dolomite (CaMg[CO3]2) nor magnesite (MgCO3). After 20 d of recarbonation for LANL, Mg2+ solubility decreased from 10−2.78 M to 10−3.15 M. The experimental findings in this study further suggest that bubbling CO2(g) through retorted shales can reduce the concentrations of F and, in some cases Mo, in leachates.
Field Chambers for Assessing Crop Loss from Air Pollutants
Authors: Musselman R. C. , Mc Cool P. M. , Oshima R. J. , Teso R. R. 
Published: July 2010

AbstractA new field fumigation facility has been developed for determining effects of air pollutants on crops. The permanent facility consists of closed‐top, octagonal chambers 2.1 m tall by 2.5 m across. Each chamber is supplied with air via underground ducting from two centralized blowers, one charcoal‐filtered and the other nonfiltered. Individual chambers can be adjusted to 100% filtered air for fumigation with specific levels of pollutants, or a pollutant gradient can be generated by combining filtered and ambient air. Air exchange rates through the chambers are also adjustable. Each chamber is constructed of several flat aluminum‐frame panels covered with Teflon film which has remained clear and durable after three years of continuous service. Panels are easily removed for repair if necessary. Teflon film walls minimize environmental differences between chamber and ambient air. Chamber temperatures closely track ambient, but are higher than ambient at midday. Temperatures remain uniform at different locations within each chamber. Light intensity within chambers averages 11% less than ambient. Pollutant levels set within each chamber remain relatively stable in both time and space. Native soil under each chamber has been replaced with a standard greenhouse soil mix which is irrigated with a drip system. The fumigation facility is comparable in construction costs to open‐top fumigation chamber systems, and is especially useful for experiments requiring precise control of pollutant levels.
The Effects of Tailing Dam Profiles on Relative Wind Erosion Rates
Authors: Coffey P. S. , Scott W. D. , Summers K. J. 
Published: July 2010

AbstractErosion from mine treatment and associated residue areas can pose a significant environmental problem for surrounding locations from dust and other transported materials. The shape of such residue areas can influence windfield behaviour by causing significant wind speed increases. Residue areas are often unprotected so that increasing the speed of wind passing over these areas will cause extra erosion. Values of wind speed‐up predicted by an empirical model for wind flow over hills of low slope were compared with measured values over approach slopes to tailings dam. Hunt's model used in this study relates wind speed from a point on the hill to that observed if there was no hill. Measured values are in agreement with those predicted by the model. Shear stress values calculated from the wind flow model are then used to determine the friction velocity which, in turn, predict the relative rates of erosion. This prediction is based on the cubic relation between the friction velocity and erosion rate observed by Bagnold. These calculations are repeated for the various possible hill shapes allowed by the plant layout and the need to integrate long term spoil heaps with existing topography. A strategy for minimizing erosion of mine tailings through shape selection can then form part of the environmental considerations associated with tailings dams.
Fate of Diclofop‐methyl After Application to a Wheat Field
Authors: Smith A. E. , Grover R. , Cessna A. J. , Shewchuk S. R. , Hunter J. H. 
Published: July 2010

AbstractDissipation of diclofop‐metnyl, the methyl ester of the herbicide diclofop ((±)‐2‐[4‐(2,4‐dichlorophenoxy)phenoxy] propanoic acid), and its acid metabolite (diclofop) in atmospheric, agronomic, and edaphic components were measured in a wheat (Triticum aestivum L.) field during and following application on 29 June 1982. Drift losses during application were <0.1% of the applied herbicide. Air samples, collected at six heights (ranging from 30–200 cm) above the crop canopy during the first 7 d after application did not show measurable levels of diclofop‐methyl, thus indicating minimal losses due to volatilization. The crop canopy intercepted 21% of the applied ester. On entry into the crop, the ester was rapidly hydrolyzed to the metabolite diclofop acid, so that after 5 d only 2% of the intercepted ester could be solvent washed from the treated wheat. At first there appeared to be a rapid metabolism of diclofop acid in the wheat, with approximately 5% of initially applied ester remaining in the acid form after 5 d. Thereafter, the rate of loss of the acid was slower, but metabolism of the diclofop acid was essentially complete after 32 d. No diclofop ester or acid was detected in the wheat straw or grain at harvest 88 d after application. In the soil, hydrolysis of the methyl ester to diclofop acid was rapid and complete within 9 d of application. The acid underwent slow breakdown in the field soil and on 14 October, 126 d after application, 19% of the initial herbicide treatment was still present in the top 7.5‐cm soil depths as diclofop acid.
Boron Deposition on Soil and Native Vegetation from Geothermal Emissions
Authors: Lang F. J. , Bingham F. T. , Hendrix F. F. , Crane N. L. 
Published: July 2010

AbstractBoron deposition, soil B, and foliage B were sampled in a field study around two geothermal generating units with different operating histories; the study also determined relative sensitivities of several native tree species to B in soil and foliage. Boron emissions from the older cooling tower, operational for 11 yr, were nearly 5 times greater than emissions from the newer cooling tower, operational for 2.5 yr. This difference was due to substantially greater B concentrations in circulating water at the older unit. Boron deposition was as great as 129.6 kg ha−1 yr−1 at the older unit and 4.2 kg ha−1 yr−1 at the newer unit. Soil B (saturation extract) was as great as 44.0 mg L−1 at the older unit and 0.6 mg L−1 at the newer unit. At a given rate of B deposition, soil B was more than 4 times greater at the older unit due to its longer operating history. At a given soil B level, the deciduous bigleaf maple (Acer macrophyllum Pursh) contained double the foliage B of the broadleaf evergreen, interior live oak (Quercus wislizeni A. DC.), and about 5 times greater foliage B than the conifer, Digger pine (Pinus sabiniana Dougl.). Foliage B thresholds for detectable levels of visible injury due to B toxicity were about 500 mg kg−1 for both bigleaf maple and interior live oak. These relationships suggest that more rapid B accumulation is responsible for higher levels of visible injury due to B in bigleaf maples than in other native tree species.
Heavy Metals in Cottontail Rabbits on Mined Lands Treated with Sewage Sludge
Authors: Dressler R. L. , Storm G. L. , Tzilkowski W. M. , Sopper W. E. 
Published: July 2010

AbstractLevels of heavy metals in soils, vegetation, and tissues of cottontail rabbits (Sylvilagus floridanus) on a Pennsylvania strip‐mined site treated with sewage sludge were compared with those from a non‐treated mine site to determine increases due to treatment effect. Concentrations of Cd, Cu, and Zn were higher in vegetation on the sludge‐treated site. Zinc was higher (P < 0.05) in femurs of cottontails from the treated site, but levels of most metals in the tissues of cottontail rabbits from the treated site were comparable to those from a non‐treated mine site and a nonmined area. Baseline values for the uptake of Cd were documented with captive cottontail rabbits fed diets supplemented with 0, 5, or 25 mg Cd kg−1. Captive rabbits fed diets supplemented with a Cd salt accumulated increasing levels of Cd in their tissues, except for muscle, as the dietary intake of Cd increased (P < 0.05). Liver and muscle tissue of rabbits collected on treated mine sites contained higher Cd levels than laboratory controls, but overall, cottontail rabbits did not accumulate metals on the sludge‐treated site at hazardous levels.
Influence of Sulfate, Nitrate, and Chloride in Simulated Acidic Rain on Radish Plants
Authors: Jacobson J. S. , Troiano J. J. , Heller L. I. , Osmeloski J. 
Published: July 2010

AbstractThe primary objective of this research was to test the hypothesis that sulfate (SO2−4), nitrate (NO−3), and chloride (Cl−), as major anionic components of rain, significantly affect plant growth or modify plant response to the acidity of rain. In the first experiment, above‐ground portions of greenhouse‐grown radish (Raphanus sativus L.) plants were given 10 1‐h exposures over a 3‐week period to simulated rain containing the individual acids, sulfuric (H2SO4), nitric (HNO3), hydrochloric (HCl), or a combination of H2SO4 and HNO3 at pH vlaues between 2.6 and 5.0. A second experiment was performed using 2‐h exposures on 4 consecutive days to simulated rain containing either H2SO4, HNO3, or HCl at pH values between 3.0 and 5.0. Reductions in hypocotyl growth but not shoot growth were obtained at pH 2.6 in the first experiment and at 3.0 and 3.4 in the second experiment. Both the linear and quadratic components of the dose‐response function for effects of acidity on hypocotyl dry mass were significant. There were no significant effects of anions on dry mass of hypocotyls nor was there a significant acidity by anion interaction in either exposure pattern. The similarity of effects on plant growth of H2SO4, HNO3, and HCl in simulated rain suggests that differences in concentrations and ratios of SO2−4, NO−3, and Cl− in rain may not be important for agricultural crops. The validity of these conclusions should be tested for other species and different environmental, edaphic, and treatment conditions.
Effect of Cadmium‐ and Zinc‐treated Sludge on Yield and Cadmium‐Zinc Uptake of Corn
Authors: Sikora F. J. , Wolt Jeff 
Published: July 2010

AbstractSludge obtained from a regional wastewater treatment plant in Tennessee was factorially treated with four levels each of Cd and Zn and applied to Statler sandy loam surface soil (Humic Hapludults) sown to corn (Zea mays L.) in a greenhouse experiment. The highest Cd and Zn additions (75.1 and 759 mg kg−1) soil, respectively, resulted in dry weight decreases of 19 and 25%, respectively, for corn tops and 47 and 56%, respectively, for corn roots. The 19% dry weight reduction at a Cd addition of 75.1 mg kg−1 soil was considerably less than values found in the literature. This comparatively modest dry weight reduction was attributed to a lower Cd availability due to Cd precipitation or binding in the sludge. Zinc effectively competed with Cd for uptake as evidenced by a decrease in Cd content of roots with increased Zn additions. On the contrary, Cd content of tops was not consistently decreased with increased Zn application. An increase in the Zn levels of sludge was also found to increase the solubility of Cd in the sludge and soil.
Uptake by Sagebrush of Uranium Progeny Injected In Situ
Authors: Simon Steven L. , Fraley Leslie 
Published: July 2010

AbstractUptake of 226Ra, 210Pb, and 210Po in mature big sagebrush (Artemisia tridentata) was studied in the environs of a U mine in Shirley Basin, WY. Radionuclide solutions were injected into the soil to elevate the soil activity while minimizing root disturbance and preventing soil surface contamination. The objectives of this study were to measure the concentration in leaves resulting from root uptake as a function of time and to determine the equilibrium concentration ratio (CR) for each radionuclide. The vegetation was sampled approximately every 90 d for a 2‐yr period. The maximum internal plant concentration of 226Ra, 210Pb, and 210Po was detected at the first sampling (81 d after soil injection for 226Ra, 28 d for 210Pb and 210Po). The concentration in leaves decreased over time following the first sampling to an apparent steady‐state value. The steady‐state CR values for 226Ra, 210Pb, and 2100Po, as determined in mature sagebrush, were approximately 0.04, 0.009, and 0.08, respectively, and were determined as the geometric mean (GM) of the CR data pooled over the 2nd‐yr period. The CR data were fit by nonlinear least squares to a exponential function that decreased with time to a constant value.
Aerobic and Anaerobic Degradation of Aldicarb in Asceptically Collected Soils
Authors: Ou L. ‐T. , Thomas J. E. , Edvardsson K. S. V. , Rao P. S. C. , Wheeler W. B. 
Published: July 2010

AbstractDegradation and metabolism of [14C] aldicarb [2‐methyl‐2‐(methylthio)propionaldehyde O‐(methylcarbamoy) oxime] in soils under aerobic and strictly anaerobic conditions were investigated. Soils were collected aseptically from a 6‐ha tract in Dougherty Plains, GA. Under aerobic conditions, aldicarb (A) rapidly disappeared and aldicarb sulfoxide (ASO) was rapidly formed. The latter in turn was slowly oxidized to aldicarb sulfone (ASO2). Disappearance of A and formation of ASO and ASO2 were generally more rapid in surface soils and shallow subsurface soils than in deeper subsurface soils. A number of additional metabolites were detected, including thin layer chromatography (TLC)‐polar products, ASO oxime, ASO nitrile, and A acid. Half‐lives for total toxic residue (TTR) in 24 surface and subsurface soils ranged from 29 to 78 d, with an average of 52 d. Aldicarb sulfoxide was the principal metabolite in soils under strictly anaerobic conditions; ASO2, ASO oxime, and ASO acid in small quantities were detected in some soils; and TLC‐polar products were also detected in most soils. Half‐lives for TTR in three deep subsurface soils under strictly anaerobic conditions were shorter than in three shallow subsurface soils. Although A persisted considerably longer in anaerobic soils, anaerobic half‐lives for TTR in subsurface soils were significantly shorter than under aerobic conditions.
Nitrate Leaching Losses from Monolith Lysimeters as Influenced by Nitrapyrin
Authors: Owens L. B. 
Published: July 2010

AbstractThree monolith lysimeters, each with a surface area of 8.1 m2 and a depth of 2.4 m, were planted to no‐till corn (Zea mays L.) for 6 consecutive years. The lysimeters contained a Rayne silt loam (Typic Hapludult), a well‐drained residual soil. Urea was placed in a slot approximately 10‐cm deep and 10 to 15 cm from the corn row at a rate of 336 kg N/ha. The urea applied to two of the lysimeters was treated with nitrapyrin [2‐chloro‐6‐(trichloromethyl)pyridine], a nitrification inhibitor, and applied untreated on the third lysimeter. Two years of unfertilized meadow immediately preceded the corn. Concentrations of NO−3; in the leachate from the lysimeters were higher during the corn years than during the meadow period. Concentrations showed seasonal variations during the last 3 yr of the study, but showed no increasing trend. The leachate from the lysimeters receiving the nitrapyrin treated urea had seasonally flow‐weighted NO−3; concentrations ranging from 6 to 40 mg/L, while the leachate from the lysimeter receiving untreated urea had seasonally flow‐weighted NO−3;‐N concentrations ranging from 20 to 54 mg/L. Nitrate‐N losses showed a similar treatment difference. The 6‐yr annual average NO−3; loss was 117 and 160 kg/ha from the lysimeters with the treated urea and untreated urea, respectively. This study demonstrates that nitrification inhibitors such as nitrapyrin, have a potential to reduce NO−3; leaching when applied with ammoniacal fertilizers.
Extent of Regeneration of the Microbial Community in Reclaimed Spent Oil Shale Land
Authors: Segal William , Mancinelli Rocco L. 
Published: July 2010

AbstractSince the microbial community is an integral component of the soil ecosystem, an understanding of the microbiological parameters of reclaimed spent oil shale land is essential for environmental assessment of the potential for reclamation of such land. It was found that determination of the numbers of microorganisms, bacterial diversity and richness (number of genera), and biogeochemical activity indicated by relative rates of cellulose decomposition, yielded significant information regarding the regenerative potential of the microbial communities sampled from three shale mining areas in Colorado and Wyoming that had undergone varying degrees of weathering, leaching, fertilization, and revegetation. Compared to regional soils used as controls, the spent oil shale soils were characterized by low numbers of microorganisms, depressed values of bacterial diversity and richness, and low rates of cellulose decomposition. However, samples taken from 6‐yr revegetated sites were characterized by the least reduction in microbial numbers, higher indices of diversity and richness, and highest rates of cellulose decomposition, in comparison to intermediate values for the 3‐yr revegetated site, and the most extreme values for the nonrevegetated site. The latter site was characterized by very reduced numbers of bacteria, actinomycetes, and fungi, the lowest indices of richness and diversity indicative of a high level of environmental stress, and no decomposition of cellulose. It may be concluded that oil shale processing had a drastic negative impact on indigenous microbial communities in reclaimed, shale land. However, conditioning by weathering, fertilization, and revegetation does have a partially restorative effect on the microbial community; the degree of restoration progressively increasing with increasing length of time of these environmental conditions.
Water and Sediment Sampler for Plot and Field Studies
Authors: Dressing S. A. , Spooner J. , Kreglow J. M. , Beasley E. O. , Westerman P. W. 
Published: July 2010

AbstractThe design and performance characteristics of a flush‐type sampling device for plot and field studies are described. The sampler is weld‐constructed and requires excavation and water conveyance for installation. It operates with no external power supply and collects consistently a known fraction of water and sediment passing through it. In laboratory tests, the sampler collected 2.65% (number of data points [n] = 54, standard deviation [s] = 0.0040) of all water passing through it at average flow rates ranging from 18 to 196 L min−1. Sample volumes ranged from 0.75 to 18.7 L. Correlation analysis showed that sampling percentage was independent of flow rate (n = 40, correlation coefficient = r = −0.04) over the range tested, in other laboratory tests, 30 sampling runs with inflow rates and total sediment concentrations ranging from 35 to 182 L min−1 and 252 to 1410 mg L−1, respectively, showed that the ratios of waste to sample sediment concentrations were approximately one for total sediment (1.001), and for the sand (1.097), silt (1.008), and clay (1.020) fractions. Sand and clay ratios were shown to be statistically independent of total sediment concentration, but silt (r = 0.30, n = 30) and total sediment (r = 0.44, n = 30) ratios increased slightly with increasing total concentration. Monte Carlo simulation was performed to illustrate the suitability of the flush‐sampler for field and plot runoff studies. Simulation results indicated that for runoff estimates measurement error would exceed 10% with 33% probability for triplicate plots, but with only 16% probability in five plot studies. Additional simulation considering only measurement error associated with the sampler shows that the minimum number of paired samples required to detect sediment loss reductions of 50, 25, and 10% is 3, 4, and 16, respectively.