bluuebunny/crossref_metadata_2025_split huggingface dataset:
Denitrification from Soils of a Year‐Round Forage Production System Fertilized with Liquid Dairy Manure
Authors: Lowrance R. , Johnson J. C. , Newton G. L. , Williams R. G. 
Published: July 2010

AbstractDenitrification is an important potential sink for N in liquid manure and the amount of denitrification may affect sustainability of crops grown with liquid manure as a nutrient source. This study examined gaseous N loss by denitrification and the changes in soil N pools after liquid manure application. Liquid dairy manure was applied at four N rates (246, 427, 643, and 802 kg N ha−1 yr−1) to four quadrants of a center‐pivot in a year‐round forage production system. Denitrification (using the acetylene block technique on intact cores) and soil N pools were determined before and for 2 yr after beginning liquid manure application. Nitrous oxide evolution from soil cores was compared to denitrification for a third year of the study. Denitrification rates and soil N pools increased after manure application at all rates of application. The two highest rates of manure had highest denitrification rates, although differences in soil moisture due to soil and drainage properties complicated the interpretation of manure rate effects. At the two highest rates of N application and two lowest rates of N application, the quadrant with higher soil moisture had higher denitrification. Nitrous oxide emissions accounted for about 29% of total denitrification. Denitrification ranged from 11 to 37% of total N applied in the manure. Highest rates of denitrification and highest proportions of total N denitrified were found with the second highest manure application rate because these soils were wetter. Annual denitrification totals ranged from 32 to 114% of the excess N (application‐crop uptake) available.
Lead Exposure of Waterfowl Ingesting Coeur d'Alene River Basin Sediments
Authors: Beyer W. Nelson , Audet Daniel J. , Morton Anna , Campbell Julie K. , LeCaptain Leonard 
Published: July 2010

AbstractFeces from tundra swans [Cygnus columbianus (Ord)], Canada geese [Branta canadensis (L.)], and mallards [Arias platyrhynchos (L.)] were collected from the Coeur d'Alene River Basin and two reference areas in Idaho to estimate exposure to lead from mining activities and relate that exposure to the ingestion of contaminated sediments. The average acid‐insoluble ash content of the feces, a measure of sediment ingestion, was 18% for Canada geese and tundra swans, and 12% for ducks. The 18% value corresponded to an estimated 9% sediment ingestion rate (dry weight). The 90th percentile for acid‐insoluble ash in feces of tundra swans corresponded to an estimated 22% sediment in the diet. The average lead concentration (dry weight) of tundra swan feces from all Coeur d'Alene River Basin wetlands sampled was 880 mg/kg, compared to 2.1 mg kg−1 from reference areas. The 90th percentile of lead in tundra swan feces from the Coeur d'Alene River Basin sites was 2700 mg kg−1. Fecal lead concentrations of tundra swans were correlated (Spearman's rho = 0.74, P < 0.05) with the acid‐insoluble ash content of the feces. The very low lead concentrations in feces having low acid‐insoluble ash contents established that the sediment was the primary source of the lead ingested by waterfowl. Sediment lead concentrations at 11 wetland sites were closely correlated (r = 0.91, P < 0.05) with average fecal lead concentrations for all waterfowl, corrected for the average percent acid‐insoluble ash in the feces.
Water Quality in Walnut Creek Watershed: Herbicides and Nitrate in Surface Waters
Authors: Jaynes D. B. , Hatfield J. L. , Meek D. W. 
Published: July 2010

AbstractThere is a lack of quantitative information describing the impact of farming on water quality at the watershed scale. This study documents the surface water quality of Walnut Creek—a 5130‐ha watershed with about 86% of the land used for crop production. Starting in 1990, flow and concentrations of NO3‐N and four herbicides—atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine], alachlor [2‐chloro‐N‐(2,6‐diethylphenyl)‐N‐(methoxymethyl)acetamide], metribuzin [4‐amino‐6‐(1,1‐dimethylethyl)‐3‐(methylthio)‐1,2,4‐triazin‐5(4N)‐one], and metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl) ‐ N ‐ (2 ‐methoxy ‐1‐methylethyl)acetamide]—were measured at eight locations. Nitrate‐N concentrations often exceeded 10 mg L−1 during May, June, and July. Total losses from the watershed ranged from 4 to 66 kg ha−1 yr−1 and represented 6 to 115% of the N applied as fertilizer in any year. Atrazine and metolachlor were detected at concentrations >0.2 µg L−1 in about half of all water samples, while alachlor and metribuzin were seldom detected. Median concentrations for atrazine and metolachlor were below 1 µg L−1 for all locations within the watershed. During runoff events, herbicide concentrations in the stream increased while NO3‐N concentrations decreased. Yearly losses from the watershed ranged from 0.2 to 7.5 g ha−1 for atrazine and from 03 to 6.7 g ha−1 for metolachlor. These losses represent 0.18 to 5.6% of the atrazine and 0.047 to 1.6% of the metolachlor applied in any year.
Geology, Groundwater Flow, and Water Quality in the Walnut Creek Watershed
Authors: Eidem J. M. , Simpkins W. W. , Burkart M. R. 
Published: July 2010

AbstractAn investigation of the Walnut Creek watershed was performed to characterize the geology, groundwater flow, and water quality in geological units impacted by agriculture. Six Quaternary lithostratigraphic units induding alluvium of the DeForest Formation, till of the Dows and Wolf Creek Formations, and loess of the Peoria, Pisgah, and Loveland Formations, along with two pedostratigraphic units, the Farmdale and Sangamon Geosols, were identified. The thickness and spatial distribution of the units were controlled by the formation of a paleo‐valley before the advance of the Des Moines Lobe, sediment movement into the paleo‐valley, and later erosion and deposition by the Des Moines Lobe. Groundwater flows toward the creek under unconfined conditions in the fractured, oxidized zone of till of the Dows Formation. Tritium data indicate that recent recharge occurs at the water table and that the 1963 bomb peak occurs near the bottom of the oxidized zone. Fifty‐five percent of groundwater samples taken in 1995 showed NO3‐N concentrations at or above the MCL of 10 mg/L; pesticides were detected in two samples. Some of the highest concentrations of NO3‐N occur in bomb peak groundwater near the base of the oxidized zone. This relationship implies that NO3‐N leaching has decreased during a period of increased N application in Iowa. It may actually reflect an increase in tile drain efficiency, decrease in groundwater recharge, and resultant isolation of NO3‐N in less‐mobile groundwater. Agricultural practices that further decrease NO3‐N leaching will be needed to improve the quality of shallow groundwater in the watershed.
Deconstruction of the Chemical Effects of Road Salt on Stream Water Chemistry
Authors: Mason Charles F. , Norton Stephen A. , Fernandez Ivan J. , Katz Lynn E. 
Published: July 2010

AbstractThe chemistry of a first‐order stream in Amherst, ME, with a catchment area of 103 ha has been strongly altered as a result of road salt application at a rate of approximately 4 t of NaCl per year in the lower 15% of the catchment. Downstream from the road, elevated stream Cl is accompanied by elevated Ca, K, Mg, and Na. The chemistry of the stream was deconstructed to identify the impact of the salt on total stream chemistry. Components quantified include precipitation (including dry deposition), chemical weathering, road salt, and cation exchange. Sodium from the road salt displaces Ca, K, and Mg from the soil on an equivalent basis. The displacement was at a maximum in late Fall and early Spring, indicating a long residence time for the NaCl. The exchange process was reversible. With continued loading of NaCl the water chemistry should reach a steady state such that Na and Cl move through the soil in a relatively conservative way, when the soils are at equilibrium with elevated concentrations of Na. Concentrations of Ca, K, and Mg in stream water should concurrently return to pre‐salting values under the new steady state.
Removal of Aromatic Amines from Water by Montmorillonite‐(Cerium or Zirconium) Phosphate Crosslinked Compounds
Authors: González‐Pradas E. , Villafranca‐Sánchez M. , Del Rey‐Bueno F. , García‐Rodríguez A. , Ureña‐Amate M. D. 
Published: July 2010

AbstractTo evaluate the potential use of two montmorillonite‐(Ce or Zr) phosphate crosslinked compounds in removing organic pollutants such as aniline, p‐toluidine, and p‐acetylaniline from water, adsorption experiments were performed under conditions of varied temperature (288 and 308 K). Adsorption on the montmorillonite‐Ce‐phosphate compound was best described by a hyperbolic (H‐type) isotherm, whereas for the montmoriilonite‐Zr‐phosphate compound, S‐type isotherms were obtained for p‐toluidine and aniline and L‐type for p‐acetylaniline. Amines adsorption increases with increasing temperature on the cerium crosslinked material, while for the zirconium‐crosslinked compound, adsorption decreases as temperature increases from 288 to 308 K, possibly due to a mainly physical process. Fourier‐transform infrared (FTIR) spectroscopy indicated that at the pH generated by the adsorbents, the protonated species of these amines plays an important role in the adsorption process. X‐ray diffraction analysis showed that the aromatic amines are intercalated into the adsorbents. For any given amine, the cerium‐montmorillonite adsorbent shows a higher capacity of adsorption compared with zirconium‐montmorillonite adsorbent, so it might be reasonably used in removing aromatic amines from water.
Isoproturon Sorption and Degradation in a Soil from Grassed Buffer Strip
Authors: Benoit P. , Barriuso E. , Vidon Ph. , Réal B. 
Published: July 2010

AbstractThe fate of the herbicide isoproturon [3‐(4‐isopropylphenyl)‐l,1‐dimethylurea] was investigated in soil from a grassed buffer strip. Compared to a cropped soil originating from the same experimental site (Kd = 1.8 L kg−1), sorption of isoproturon was enhanced in the grassed soil and especially in the surface layer (0‐2 cm) containing high proportion of nondecomposed plant residues (Kd = 5.0 L kg−1). Nonhumified organic fractions isolated from the surface soil layer and corresponding to above and bdow‐ground plant residues derived from the grass exhibited high sorption coefficients Kd and Koc compared to the rest of the soil. Reversibility of sorption was lower in the grassed soil than in the cropped soil and decreased rapidly with time. A rapid degradation of isoproturon was observed at different depths of the grassed soil whereas most of the herbicide remained nondegraded in the cultivated soil: half‐lives were respectively 72 d in the cultivated soil, and only 8 d in the superficial layer (0–2 cm) of the grassed soil. The highest mineralization rate of the isoproturon ring (20% after 35 d) was observed in the top layer (0–2 cm) having the highest mineralization rates of organic matter. In relation with this fast degradation, a large proportion of isoproturon residues became nonavailable to water and methanol extractions (54% of the initial applied isoproturon found as nonextractable (bound) residues). Thus the grassed strip surface soil had a high potential to dissipate isoproturon trapped from run‐off.
Deicing Salt Accumulation and Loss in Highway Snowbanks
Authors: Buttle J. M. , Labadia C. F. 
Published: July 2010

AbstractEnvironmental impacts of road deicing salt are well known, although salt pathways following application have rarely been quantified. Deicing salt (NaCl) fate was determined from retention and loss in snow cover adjacent to a 14‐km section of highway in southern Ontario during the 1994–1995 winter. Total salt application was ∼530 Mg (29–74 kg m−1 length). Retention in snow cover in the highway right‐of‐way (ROW) decayed as a power function of distance from the highway, although melting of proximal snowbanks with high salt loads disrupted this pattern. Peak concentrations in snowbanks reached 6506 (Na+) and 9916 (Cl−) mg L−1. Wind transport of salt from the ROW was minor and restricted to relatively exposed sites. Almost all applied NaCl reached the soil surface via (i) direct runoff and infiltration of saline water from the road into the shoulder and ROW, and (ii) transfer of salt to snow cover adjacent to the highway and release during snowmelt. Total salt flux along the two pathways during a 49‐d period was similar. Salt transfer via road runoff occurred during or shortly after application, unlike the intermittent fluxes from snow to soil surfaces in the ROW during this period. The latter were relatively uniform along the highway (3–5 kg m−1 length of highway), accounting for 39 to 65% of applied NaCl. However, magnitude and timing of water and salt fluxes from snow to soil varied within the ROW and should be considered when modeling salt transport to groundwater.
Relationship between Phosphorus Levels in Three Ultisols and Phosphorus Concentrations in Runoff
Authors: Pote D. H. , Daniel T. C. , Nichols D. J. , Sharpley A. N. , Moore P. A. , Miller D. M. , Edwards D. R. 
Published: July 2010

AbstractSoils that contain high P levels can become a primary source of dissolved reactive P (DRP) in runoff, and thus contribute to accelerated eutrophication of surface waters. In a previous study on Captina soil, several soil test P (STP) methods gave results that were significantly correlated to DRP levels in runoff, but distilled H2O and NH4‐oxalate methods gave the best correlations. Because results might differ on other soils, runoff studies were conducted on three additional Ultisols to identify the most consistent STP method for predicting runoff DRP levels, and determine effects of site hydrology on correlations between STP and runoff DRP concentrations. Surface soil (0–2 cm depth) of pasture plots was analyzed by Mehlich III, Olsen, Morgan, Bray‐Kurtz P1, NH4‐oxalate, and distilled H20 methods. Also, P saturation of each soil was determined by three different methods. Simulated rain (75 mm h−1) produced 30 min of runoff from each plot. All correlations of STP to runoff DRP were significant (P < 0.01) regardless of soil series or STP method, with most STP methods giving high correlations (r > 0.90) on all three soils. For given level of H2O‐extractable STP, low runoff volumes coincided with low DRP concentrations. Therefore, when each DRP concentration was divided by volume of plot runoff, correlations to H2O‐extractable STP had the same (P < 0.05) regression line for every soil. This suggests the importance of site hydrology in determining P loss in runoff, and may provide a means of developing a single relationship for a range of soil series.
Reducing Nitrogen Losses during Simulated Composting of Poultry Manure using Adsorbents or Chemical Amendments
Authors: Kithome M. , Paul J. W. , Bomke A. A. 
Published: July 2010

AbstractAmmonia emissions during composting of poultry manure can be significant, representing increased environmental pollution and decreased fertilizer value of manure. The objectives of this study were to measure NH3 volatilization losses during composting of poultry layer manure, and to evaluate the potential of different amendments to reduce NH3 losses using a laboratory composting simulator. The poultry manure was treated with various amendments which included two natural zeolites, clay, coir (mesocarp of coconut fruit), CaCl2, CaSO4, MgCl2, MgSO4, and Al2(SO4)3. The manure was composted for 49 to 56 d. Ammonia volatilized from the manure was trapped in a 0.3 M H2SO4 solution. The composts were weighed and analyzed for moisture content, total N and NH+4. The NH3 volatilization loss for the unamended manures ranged from 47 to 62% of the total manure N. A layer of 38% zeolite placed on the surface of the manure reduced NH3 losses by 44%, whereas 33% coir placed on the surface of the manure reduced NH3 losses by 49%. The 20% alum treatment reduced NH3 losses by 28%. Composting poultry manure with zeolites, coir, and alum produced composts with high NH+4 concentrations ranging from 17 to 53% of total N. The addition of 20% CaCl2 to poultry manure decreased NH3 volatilization but did not result in increased NH+4 or NO−3 concentrations. The 38% zeolite Z1 and 33% coir‐treated composts had total N concentrations of 17 and 31 g kg−1, respectively. The zeolite and coir amendments were proposed to be the most suitable for reducing NH3 losses during composting of poultry manure.
Temporal Variations in Greenhouse Gas Emissions at a Midlatitude Landfill
Authors: Bogner J. E. , Spokas K. A. , Burton E. A. 
Published: July 2010

AbstractA field study encompassing a parallel time series of CH4, N2O, and CO2 emissions measurements was completed by using static enclosure techniques at a midlatitude landfill (northeastern Illinois) during the period of July through December 1995. The site had a pumped gas recovery system and thus a high level of engineered gas control. No net CH4 emissions to the atmosphere were measured during this study; rather, the landfill cover soils were functioning as a sink for atmospheric CH4. The net measured emissions of CO2 (dark respiration) and N2O were in ranges characteristic of natural soils and were dependent on similar controls, including temperature, moisture, and aeration status. A comparison of proximal (near gas recovery well) and distal (between wells) emissions with soil gas profiles permitted development of a conceptual biogeochemical model for gas transport and reaction through the landfill cover. This model includes a modified reduction sequence where the major zones (from ground surface downward) were a near‐surface zone of optimum CH4 oxidation; a zone of optimum CO2 production (predominantly from root zone respiration); a zone of optimum N2O production; and a deep zone dominated by transport of landfill gas (CH4 and CO2) from methanogenic production zones in the underlying refuse.
Phytoaccumulation of Trace Elements by Wetland Plants: II. Water Hyacinth
Authors: Zhu Y. L. , Zayed A. M. , Qian J‐H. , de Souza M. , Terry N. 
Published: July 2010

AbstractWetland plants are being used successfully for the phytoremediation of trace elements in natural and constructed wetlands. This study demonstrates the potential of water hyacinth (Eichhornia crassipes), an aquatic floating plant, for the phytoremediation of six trace elements. The ability of water hyacinth to take up and translocate six trace elements—As(V), Cd(II), Cr(VI), Cu(II), Ni(II), and Se(VI)—was studied under controlled conditions. Water hyacinth accumulated Cd and Cr best, Se and Cu at moderate levels, and was a poor accumulator of As and Ni. The highest levels of Cd found in shoots and roots were 371 and 6103 mg kg−1 dry wt., respectively, and those of Cr were 119 and 3951 mg kg−1 dry wt., respectively. Cadmium, Cr, Cu, Ni, and As were more highly accumulated in roots than in shoots. In contrast, Se was accumulated more in shoots than in roots at most external concentrations. Water hyacinth had high trace element bioconcentration factors when supplied with low external concentrations of all six elements, particularly Cd (highest BCF = 2150), Cr (1823), and Cu (595). Therefore, water hyacinth will be very efficient at phytoextracting trace elements from wastewater containing low concentrations of these elements. We conclude that water hyacinth is a promising candidate for phytoremediation of wastewater polluted with Cd, Cr, Cu, and Se.
Automated Sequential Sampler for Collection of Highly Volatile Atmospheric Contaminants
Authors: Wang D. , Ernst F. F. , Yates S. R. 
Published: July 2010

AbstractRapid and accurate measurement of atmospheric concentrations of highly volatile organic compounds is important in obtaining reliable information for the assessment of environmental pollution or the volatilization mechanisms of the chemicals. Nonmechanized sample collection requires intensive labor and effort, and may cause large random or systematic errors. An automated solenoid switching system was developed to assist in obtaining precise environmental concentrations of highly volatile organic compounds. The design, construction, and operation are described in the paper for potential application in similar studies. Using this sampling system, two experiments were conducted to determine atmospheric volatilization flux density of three highly volatile and reactive organic compounds (methyl bromide, 1,3‐dichloropropene, and propargyl bromide). The automated solenoid switching system significantly reduced the requirements for labor and time. Results from the two experiments indicate that reliable sample collection was achieved. The automated sampling system was also relatively inexpensive and can be easily modified to accommodate a variety of sources, sampling intervals, and multiple number of solenoid valves.
Uncertainty Assessment in Modelling Soil Acidification at the European Scale: A Case Study
Authors: Kros J. , Pebesma E. J. , Reinds G. J. , Finke P. A. 
Published: July 2010

AbstractWhen modelling soil acidification at the European scale, it is inevitable that both model and data have varying degrees of associated uncertainty. The present study attempted to quantify the uncertainty in long‐term forecasts of soil solution concentrations of Al3+ and NO−3 concentrations resulting from the uncertainty in small resolution European‐scale maps and input data, using the Netherlands as a case study. Large‐scale forecasts were made with a relatively simple dynamic process‐oriented model, SMART2. Model outputs were considered as block median concentrations and the block areal fractions in which concentrations exceeded a critical level. Sources of uncertainty considered included (i) uncertainty in soil and vegetation maps (categorical data), and (ii) uncertainty in soil and vegetation‐related parameters (continuous data). The uncertainty in model outputs was quantified by an efficient two‐step Monte Carlo simulation approach, which takes spatial correlation into account. The uncertainty in the input data at the European scale led to major uncertainties in the predicted Al3+ concentration. Uncertainties in the areas where the Al3+ concentration exceeded the maximum allowable concentration were much smaller. The uncertainties in soil‐related parameters contributed most to the uncertainty in the A3+ concentration, whereas the uncertainty contributed by the soil and vegetation maps was negligible. For the NO−3 concentration, however, the uncertainty originated mainly from the soil and vegetation maps. Evaluation of the different error sources is of great practical significance, as it identifies which sources need further improvement. The present study shows that the uncertainty contribution of the different error sources depends greatly on the model output considered.