bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of Cesium‐134 and Strontium‐85 Crop Uptake Based on Soil Properties
Authors: Roca M. C. , Vallejo V. R. , Roig M. , Tent J. , Vidal M. , Rauret G. 
Published: July 2010

AbstractNowadays, there is still the need to improve the quantification of parameters that affect radionuclide mobility. With this aim, radiocesium and radiostrontium soil‐to‐plant transfer was measured in lysimeters in a Calcic Luvisol, loamy soil and in a Fluvisol, loam‐sandy soil, using lettuce [Lactuca sativa L. cv. Kinemontepas] and pea plants [Pisum sativum L. cv. Kelvedon Wonder]. Weighted Concentration Ratios (WCR), expressed as kg soil/kg plant, were calculated for different growth stages. Weighted Concentration Ratios were in general higher for 85Sr than for 134Cs, and also higher in the loam‐sandy than in the loamy soil. To predict plant uptake, we evaluated a set of soil properties to define a prediction factor for the relative transfer in the two soils using cation exchange capacity (CEC) and radionuclide available fraction (fav)for radiostrontium, and soil solution composition, solid‐liquid distribution coefficient, and radionuclide available fraction for radiocesium. The ratios of WCR in the loam‐sandy and loamy soil were compared with the prediction factor. There was good agreement in lettuce for 85Sr (ratio of WCR was 5.4 for seedling and 3.9 for commercial samples, whereas prediction factor was 3.1) and for 134Cs (ratio of WCR was 5.1 for seedling and 5.5 for commercial samples, the prediction factor being 5.1), although for pea only the relative root uptake of radiocesium in seedling pea was well predicted (the ratio of WCR was 8.8, the prediction factor being 9.1). These soil parameters improved former predictions based solely on the fav, although factors depending on plant physiology should be better evaluated.
Prediction of Parameters Describing Phosphorus‐Desorption Kinetics in Soils of Galicia (Northwest Spain)
Authors: García‐Rodeja I. , Gil‐Sotres F. 
Published: July 2010

AbstractThe risk of eutrophication due to loss of soil phosphorus (P) in runoff can be assessed by means of models simulating the release of soil P and its transport in runoff. One limitation of these models is that they seldom take into account the kinetics of P desorption from soil. In this work, to facilitate inclusion of kinetic aspects of P desorption in these models, equations to estimate parameters describing P‐desorption kinetics from soil properties were developed. A modified Freundlich equation and several equations commonly used to describe P‐desorption kinetics were fitted to kinetic data for P desorption from 31 surface horizons of soils of Galicia (Northwest Spain). Correlations were then determined between the parameters of these kinetic equations and soil physicochemical properties. Correlated properties were Al and Fe content and soil P fixation indices determined 1 d and 1 wk after P addition. By means of stepwise multiple regression analysis, equations were obtained that allow estimation of parameters describing P‐desorption kinetics from soil properties, the dose of added P, and the soil‐P contact time.
A Water Balance Study of Four Landfill Cover Designs Varying in Slope for Semiarid Regions
Authors: Nyhan J. W. , Schofield T. G. , Starmer R. H. 
Published: July 2010

AbstractThe goal of waste disposal in landfills is to reduce risk to human health by isolating contaminants until they no longer pose a hazard. To achieve this, the performance of a landfill cover design without an engineered barrier (Conventional Design) was compared with designs containing either a hydraulic barrier (USEPA Design) or two capillary barriers (Loam and Clay Loam Capillary Barrier Designs). Water balance parameters were measured at 6‐h intervals for these designs in 1.0 by 10.0 m plots with downhill slopes of 5, 10, 15, and 25%. Whereas runoff generally accounted for only 2 to 3% of the precipitation losses on these designs from December 1991 through July 1995, similar values for evaporation ranged from 86 to 91%. Evaporation usually increased with increases in slope in our field plots; the Conventional Design at slopes of 5 and 25% exhibited 139 and 162 cm of evaporation, respectively. Consequently, interflow and seepage usually decreased with increasing slope: interflow decreased from 10.7 to 1.5 cm for the Clay Loam Capillary Barrier Design at slopes of 5 and 25%. Although seepage comprised up to 10% of the precipitation on the Conventional Design, seepage did not occur in either the USEPA design or the capillary designs at the larger slopes.
Spatial Variability of Nitrous Oxide Fluxes and Controlling Soil and Topographic Properties
Authors: Ball Bruce C. , Horgan Graham W. , Clayton Helen , Parker John P. 
Published: July 2010

AbstractSpatial heterogeneity of nitrous oxide (N2O) flux was characterized along with various soil chemical, physical, and microtopographical properties to identify those determining flux in fertilized grassland in spring 1993 and in fertilized winter wheat in spring 1994. Measurements were made at random locations within regular grids. Nitrous oxide emission was measured using closed chambers at 84 locations in each grid, spread over 2 d. The ranges of emissions from the grassland and from the winter wheat were 0 to 134 and 0 to 26.4 g N2O‐N ha−1 d−1. Variograms for N2O emission and for concentrations in the soil atmosphere at 100 mm depth indicated that spatial dependence was weak at both sites. Of the other properties, pH and nitrate showed weak autocorrelation but none of the soil physical properties showed any significant spatial dependence. The results of multiple linear regression suggested that denitrification was the main N2O production process at the grassland site, but nitrification may have been equally important at the drier winter wheat site. At both sites, the highest N2O emissions were associated with areas of a few square centimeters to a few square meters, lying below the average slope. Use of a partial least squares regression technique to predict nitrous oxide flux revealed the contribution of air permeability in addition to nitrate, ammonium, and soil water contents. Our analyses suggested that nitrous oxide production, consumption, and transport processes varied markedly with depth (over a few centimeters) near the soil surface.
Adsorption of Trace Metals by Tension Lysimeters: Nylon Membrane vs. Porous Ceramic Cup
Authors: Wenzel W. W. , Sletten R. S. , Brandstetter A. , Wieshammer G. , Stingeder G. 
Published: July 2010

AbstractLysimeters constructed of polyacrylic and fitted with either a porous nylon membrane or a porous ceramic cup were tested for their adsorption characteristics with respect to Pb, Cr, Cu, As, Cd, Co, Mn, Ni, and Zn. Laboratory tests were conducted at pH 4, 5, and 6 using metal concentrations that are representative of natural soil solutions. The ceramic lysimeters significantly lowered the concentrations of Cd, Co, Mn, Ni, and Zn, and almost completely removed Pb, Cr, Cu, and As from solution. The nylon lysimeters had virtually no effect on metal concentrations at pH 4 to 5, and only slightly decreased the concentrations of As, Cr, Cu, and Pb at pH 6. Based on field experience, an optimized design of the nylon lysimeter is presented using double nylon membranes to improve the mechanical resistance.
Use of Rhodamine WT to Facilitate Dilution and Analysis of Atrazine Samples in Short‐Term Transport Studies
Authors: Cook Sabrina M. F. , Linden Dennis R. 
Published: July 2010

AbstractBecause pesticide transport studies often require many samples, and certain pesticide analytical methods have small detection ranges, repeat analyses of samples that are outside of this range can be costly. Dye‐tracers often have a lower analysis cost than pesticides and can be visibly diluted to within detection range. We wanted to see if we could predict the dilution factor necessary for atrazine analysis by using a visible dye‐tracer, rhodamine WT. Rhodamine WT and Aatrex‐4L atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐1,3,5‐triazine) were surface applied to large, intact soil cores taken from three replications of 12‐yr no‐till, 2‐yr no‐till, and 12‐yr moldboard plow treatments. Cores were then rained on for 1 h with an oscillatinghead rainfall simulator at intensity = 50 mm h−1. Based on rhodamine WT concentrations, runoff, leachate, and soil extract samples were diluted to near mid‐atrazine‐detection range, on a logarithmic scale (0.9 µg L−1), for atrazine analysis by enzyme‐linked immunosorbant assay (ELISA). Only 6% of runoff and leachate samples (ntotal=262) needed additional dilution and only 0.5% of soil extract samples (ntotal=174) needed additional dilution. No predictions resulted in overdilution of samples. Rhodamine WT concentration was shown to be an effective predictor of dilution factor necessary for atrazine analysis in short‐term transport through this soil.
Impacts to a Coastal River and Estuary from Rupture of a Large Swine Waste Holding Lagoon
Authors: Burkholder JoAnn M. , Mallin Michael A. , Glasgow Howard B. , Larsen L. Michael , McIver Matthew R. , Shank G. Christopher , Deamer‐Melia Nora , Briley David S. , Springer Jeffrey , Touchette Brant W. , Hannon Elle K. 
Published: July 2010

AbstractWe tracked a swine waste spill (4.13 × 107 L) into a small receiving river and estuary. After 2 d, a 29‐km freshwater segment that the wastes had traversed was anoxic, with ca. 4000 dead fish floating and hung in shoreline vegetation. Suspended solids, nutrients, and fecal coliforms were 10‐ to 100‐fold higher at the plume's edge (71.7 mg SS/L, 39.6 mg NH+4‐N/L, and >1 × 106 cfu/100 mL, respectively; cfu, colony forming units, SS; suspended solids) than in unaffected reference sites. Elevated nutrients and an oxygen sag from the plume reached the main estuary after ca. 5 d. Increased phytoplankton production was contributed by noxious algae, Synechococcus aeruginosa and Phaeocystis globosa (108 and 106 cells/mL, respectively) after 7 to 14 d. The toxic dinoflagellates, Pfiesteria piscicida and a second Pfiesteria‐like species, increased to potentially lethal densities (103 cells/mL) that coincided with a fish kill and ulcerative epizootic. After 14 d, water‐column fecal coliforms generally were at 102 to 103 cfu/100 mL. But where the plume had hovered for the first 5 d, surface sediments mostly yielded ≥104 cfu/100 mL slurry, and after 61 d densities in surficial sediments were still at 103 to 104 cfu/100 mL. Dinoflagellate and euglenoid blooms developed and moved downestuary, where they were detected after 61 d. This study documented acute impacts to surfacewaters from a concentrated swine operation, and examined some environmental policies affecting the intensive animal operation industry.
Diuron and Simazine Losses to Runoff Water in Mediterranean Vineyards
Authors: Lennartz Bernd , Louchart Xavier , Voltz Marc , Andrieux Patrick 
Published: July 2010

AbstractThe Mediterranean climate is characterized by a hot and dry summer where occasional storm events induce erosion and runoff. The high leaching potential of pesticides to surface waters under such climate conditions are not in relation to the main body of data that originated from summer‐rain row‐crop scenarios. In this 2‐yr study we monitored runoff discharge and concentrations of the two soil applied herbicides diuron [3‐(3,4‐dichlorphenyl)‐1,1‐dimethylurea] and simazine [6‐chloro‐N2,N4‐diethyl‐1,3,5‐triazine‐2,4‐diamine] from two field sites—one tilled and one no‐till—cropped with grapevine (Vitis vinifera L.; Cinsault and Aramon, respectively). Despite a time lag of 140 d in 1994 between chemical application and first runoff event, diuron concentrations in overland flow exceeded 200 µg L−1 at the no‐till site. In 1995 the first strong rainfall‐runoff event following application carried >87 and 60% of the respective seasonal simazine and diuron loss at both sites, although it accounted for <17 and 7% of the total runoff volume at the no‐till and tilled site, respectively. At the no‐till site, seasonal diuron loss during 1995 was 1.71% of applied; the corresponding value for simazine was 1.25%. Only 0.68 and 0.79% of the respective applied diuron and simazine mass were washed from the tilled field, reflecting differences in runoff volume between sites. Pesticide losses depended primarily on runoff volume and intensity. Event average herbicide concentrations in surface runoff followed an exponential decay over time. Estimated first order rate coefficients were at least twice as large as those derived from soil samples using the alcoholic solvent extraction technique. The decreasing water availability with time compared with the herbicide content at the soil surface indicated an increasing adsorption with time.
Biodegradation of Petroleum Hydrocarbons in Soil as Affected by Heating and Forced Aeration
Authors: Yeung P. Y. , Johnson R. L. , Xu J. G. 
Published: July 2010

AbstractQuantifying the biodegradation rate of organic contaminants is important in designing and evaluating bioremediation treatments and facilities. To study the effects of temperature and forced aeration on the biodegradation rate, a soil collected from a pipeline break site and contaminated with crude oil was bioremediated in a field‐operated bioreactor near Nevis, AB, Canada under four treatments: a control with ambient temperature (averaging 20°C) and no forced aeration; heating alone (averaging 35°C); forced aeration alone (air flux was 0.4 1 min−1 m−2); and both heating and forced aeration. The soil was aggregated, amended with N and P fertilizers and packed 15‐cm deep to a bulk density of 0.65 Mg m−3 in the bioreactor. The effect of temperature on the biodegradation rate of hydrocarbons was also studied under laboratory conditions for temperatures ranging from 5 to 50°C. Both heating and forced aeration significantly affected the biodegradation of hydrocarbons, but the effect of the former was greater. Under laboratory conditions, the biodegradation rate of hydrocarbons increased with temperatures, peaking between 30 and 40°C. The half‐lives of the hydrocarbons remaining in soil in the field‐operated bioreactor were 105 d for both the heating alone and the heating and forced aeration treatments, 182 d for the forced aeration treatment and 248 d for the control.
Acetylene Transport In Shallow Groundwater for Denitrification Rate Measurement
Authors: Bragan R. J. , Starr J. L. , Parkin T. B. 
Published: July 2010

AbstractNitrate (NO3) concentrations frequently diminish in shallow groundwater (<3 m) when laterally transported through the soils of riparian zones and intermittent wetlands. Denitrification may be the major mechanism for this loss, but lack of suitable methods for direct measurement of denitrification rates in shallow groundwater limit the ability of field studies to verify this. The objective of this study was to determine if adequate acetylene (C2H2) concentrations can be maintained in the intermittently saturated, near surface soils found in riparian areas to temporarily block nitrous oxide reductase in denitrifying bacteria. Accomplishing this would allow use of the acetylene block method for denitrification rate assessment in the soils of riparian areas that are periodically saturated and with high potential for large denitrificafion rates. Method development and testing was conducted in the laboratory, using a 1.4 m3 mesocosm filled with sandy subsoil with continuous forced‐gradient radial flow. Movement of Br tracer and C2H2 injected into a central well was monitored by sampling from 25 and 50 cm distant radial wells. Both the tracer and aqueous C2H2 showed relatively uniform flow rates to the 25 cm wells, and then varied by a factor of two to the 50 cm wells. Acetylene concentrations exceeded those recommended to block NOx reduction by denitrifiers at the N2O stage. In situ denitrification rates were derived from monitored N2O concentrations. An initial field test provided additional evidence that the procedure may be useful for direct measurement of denitrification losses in a variety of natural, shallow groundwater systems.
Phosphorus Transformations in the Sediments of Delaware's Agricultural Drainageways: I. Phosphorus Forms and Sorption
Authors: Sallade Y. E. , Sims J. T. 
Published: July 2010

AbstractMany soils in Delaware's Inland Bays' watershed are high in phosphorus (P) from long‐ term manuring and fertilization and require artificial drainage (open ditches) for successful crop production. We characterized the properties, forms of P, and P sorption capacity of sediments from 17 drainage ditches as part of an ongoing effort to develop best management practices for agricultural drainage. Upper sediment layers (0–5 cm depth) were enriched in organic matter, Fe/Al oxides, soil test (Mehlich 1‐P; 0.05 N HCl + 0.025 N H2SO4) P and biologically available P (BAP) relative to lower sediment depths (5–15 cm) and to agricultural subsoils at the same depth as the ditch bottoms. Sediment BAP was comparable to values for topsoils in adjacent fields and >90% of sediment P was NH4F‐P or NaOH‐P. The P sorption capacity for top sediments ranged from 95 to 1671 mg P kg−1 and equilibrium P concentrations at zero sorption (EPC0) from 0.02 to 0.28 mg P L−1, consistently above P concentrations associated with fresh water eutrophication (0.02 mg P L−1). Soluble P concentrations in drainage ditch waters averaged 0.05, 0.06, and 0.15 mg P L−1 in the winter, spring, and summer. Sediment BAP (0–5 cm) could be predicted from Mehlich 1‐P and %OM (R2 = 0.80***) and P sorption capacity from a single point P sorption index (PSI) and %OM (R2 = 0.81”**) suggesting routine soil tests could help identify ditches with significant potential for nonpoint source pollution of surface waters.
Calcium Sulfate as a Flocculant to Reduce Sedimentation Basin Water Turbidity
Authors: Przepiora A. , Hesterberg D. , Parsons J. E. , Gilliam J. W. , Cassel D. K. , Faircloth W. 
Published: July 2010

AbstractA high‐suspended solids load in surface waters is one of the biggest water quality problems in the Piedmont region of the southeastern USA. Sedimentation basins at construction sites are designed to reduce suspended solids in discharged water, but they are not effective in reducing turbidity. A survey of sedimentation basin water at two urban construction sites showed that turbidity levels during a 9‐ to 12‐mo period were always greater than the 50‐NTU (nephelometric turbidity units) standard adopted in North Carolina for surface waters. Furthermore, water chemistry varied over time, with pH ranging from 5.8 to 8.9 and electrical conductivity (EC) ranging from 3.0 to 23.0 mS m−1. Laboratory experiments demonstrated that temporal variations in the water chemistry were likely caused by contact with concrete and crushed stone. Laboratory flocculation experiments were completed to evaluate the efficiency of calcium sulfate compounds (hemihydrate, agricultural gypsum, and phosphogypsum) as chemical flocculants for reducing the turbidity of sedimentation basin water from two field sites and for different pH conditions. Moulding plaster (hemihydrate) was a more efficient flocculant than agricultural gypsum and has fewer environmental restrictions on its use than phosphogypsum. Moulding plaster application rates of 350 to 700 mg L−1 were needed to reduce the turbidity of unstirred sedimentation basin water to 50 NTU within 3 h after addition of the flocculant. To achieve a given turbidity level, less flocculant was required for longer flocculation and settling times, or when sedimentation basin water had a lower pH.
Herbicide Contamination of Groundwater Beneath Claypan Soils in North‐Central Missouri
Authors: Blanchard P. E. , Donald W. W. 
Published: July 2010

AbstractThe impact of hydrology and site‐specific soil stratigraphy on herbicide leaching are not well understood for claypan soils. The claypan is a naturally‐occurring argillic soil horizon that limits percolation to groundwater. The primary objective of this study was to determine the extent of nonpoint source herbicide contamination of shallow groundwater beneath claypan soils. The secondary objective was to determine the relative importance of hydrology and land management to observed herbicide contamination of groundwater during a 5‐year period. The study site was the 7250 ha Goodwater Creek Watershed in north‐central Missouri. Three cropped fields with 10 yr of similar management were instrumented with 20 to 25 monitor wells each in 1991. The three fields were treated with different rates of atrazine [2‐chloro‐(4‐ethylamino)‐6‐(isopropylamino)‐s‐triazine] and alachlor [2‐chloro‐2′, 6′‐diethyl‐N‐(methoxymethyl)acetanilide] and the wells were sampled quarterly from 1991 to 1996. Atrazine was detected in 7.2% of samples, with a maximum concentration of 0.12 µg L−1 (limit of detection, LOD = 0.02 µg L−1). Alachlor was detected in 0.4% of samples with a maximum concentration of 0.14 µg L−1 (LOD = 0.11 µg L−1). Site to site variability in hydrology was more important than differences in herbicide application rates, as the field treated with the least atrazine and alachlor had the most frequent detections of atrazine, the atrazine metabolite deethylatrazine [2‐chloro‐(4‐amino)‐6‐(isopropylamino)‐s‐triazine; DEA], and the alachlor metabolite [2‐[(2,6‐diethylphenyl) (methoxymethyl)amino]‐2‐oxoethanesulfonic acid; ESA]. Groundwater recharge occurred primarily during the nongrowing season. Therefore, herbicide and metabolite leaching were limited by the extent of their degradation in the soil during the growing season. The study results demonstrate the importance of hydrologic variability, recharge timing, and chemical properties with respect to the leaching of herbicides and herbicide metabolites.
Comparative Effects of Poultry and Swine Waste Lagoon Spills on the Quality of Receiving Streamwaters
Authors: Mallin Michael A. , Burkholder JoAnn M. , McIver Matthew R. , Shank G. Christopher , Glasgow Howard B. , Touchette Brant W. , Springer Jeffrey 
Published: July 2010

AbstractDuring July 1995, a poultry waste lagoon ruptured in Duplin County, North Carolina, sending 32.6 million L of chicken waste effluent into a nearby creek and the Northeast Cape Fear River. In August 1995 a breach of a hog waste lagoon released approximately 7.6 million L of waste into a system of blackwater creeks in Brunswick County, North Carolina. The poultry waste spill occurred under high rainfall‐high river flow conditions, while the swine waste lagoon spill occurred during dry conditions. Both spills caused high turbidity and low dissolved oxygen (DO) in receiving waters, and DO levels in the Northeast Cape Fear River displayed a “sag curve” 10 d after the poultry waste spill, reaching a minimum of 1.0 mg L−1 90 km downstream. Both spills delivered high N loads to receiving waters (maxima of 92.1 mg L−1 from the poultry spill and 47.0 mg L−1 from the swine waste spill). Phosphorous concentrations reached 6.0 and 11.5 mg L−1 in receiving waters of the poultry and swine waste spills, respectively. Dense phytoplankton blooms (>100 µg chlorophyll a L−1) were measured in the blackwater creeks after the swine spill. High fecal coliform concentrations were delivered by both spills, and concentrations of the pathogenic bacterium Clostridium perfringens ranged up to 40 000 colony‐forming units (CFU) mL−1 in the receiving waters after the poultry spill. In 1995 and 1996 more than 30 animal waste lagoon breaches, overtoppings, and inundations were reported in North Carolina, demonstrating the major pollution potential of these treatment systems.