bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transport of Di(2‐ethylhexyl)phthalate (DEHP) Applied with Sewage Sludge to Undisturbed and Repacked Soil Columns
Authors: de Jonge H. , de Jonge L. W. , Blicher B. W. , Moldrup P. 
Published: June 2010

ABSTRACTMunicipal sewage sludge is often used on arable soils as a source of nitrogen and phosphorus, but it also contains organic contaminants that may be leached to the ground water. Di(2‐ethylhexyl)phthalate (DEHP) is a priority pollutant that is present in sewage sludge in ubiquitous amounts. Column experiments were performed on undisturbed soil cores (20‐cm depth × 20‐cm diameter) with three different soil types: a sand, a loamy sand, and a sandy loam soil. Dewatered sewage sludge was spiked with 14C‐labeled DEHP (60 mg kg−1) and bromide (5 g kg−1). Sludge was applied to the soil columns either as five aggregates, or homogeneously mixed with the surface layer. Also, two leaching experiments were performed with repacked soil columns (loamy sand and sandy loam soil). The DEHP concentrations in the effluent did not exceed 1.0 μg L−1, and after 200 mm of outflow less than 0.5% of the applied amount was recovered in the leachate in all soils but the sandy loam soil with homogeneous sludge application (up to 3.4% of the applied amount recovered). In the absence of macropore flow, DEHP in the leachate was primarily sorbed to mobilized dissolved organic macromolecules (DOM, 30.3 to 81.3%), while 2.4 to 23.6% was sorbed to mobilized mineral particles. When macropore flow occurred, this changed to 16.5 to 37.4% (DOM) and 36.9 to 40.6% (mineral particles), respectively. The critical combination for leaching of considerable amounts of DEHP was homogeneous sludge application and a continuous macropore structure.
Nitrogen Removal and Nitrate Leaching for Forage Systems Receiving Dairy Effluent
Authors: Woodard Kenneth R. , French Edwin C. , Sweat Lewin A. , Graetz Donald A. , Sollenberger Lynn E. , Macoon Bisoondat , Portier Kenneth M. , Wade Brett L. , Rymph Stuart J. , Prine Gordon M. , Van Horn Harold H. 
Published: June 2010

ABSTRACTFlorida dairies need year‐round forage systems that prevent loss of N to ground water from waste effluent sprayfields. Our purpose was to quantify forage N removal and monitor nitrate N (NO−3–N) concentrations in soil water below the rooting zone for two forage systems during four 12‐mo cycles (1996–2000). Soil in the sprayfield is an excessively drained Kershaw sand (thermic, uncoated Typic Quartzipsamment). Over four cycles, average loading rates of effluent N were 500, 690, and 910 kg ha−1 per cycle. Nitrogen removed by the bermudagrass (Cynodon spp.)–rye (Secale cereale L.) system (BR) during the first three cycles was 465 kg ha−1 per cycle for the low loading rate, 528 kg ha−1 for the medium rate, and 585 kg ha−1 for the high. For the corn (Zea mays L.)–forage sorghum [Sorghum bicolor (L.) Moench]–rye system (CSR), N removals were 320 kg ha−1 per cycle for the low rate, 327 kg ha−1 for the medium, and 378 kg ha−1 for the high. The higher N removals for BR were attributed to higher N concentration in bermudagrass (18.1–24.2 g kg−1) than in corn and forage sorghum (10.3–14.7 g kg−1). Dry matter yield declined in the fourth cycle for bermudagrass but N removal continued to be higher for BR than CSR. The BR system was much more effective at preventing NO−3–N leaching. For CSR, NO−3–N levels in soil water (1.5 m below surface) increased steeply during the period between the harvest of one forage and canopy closure of the next. Overall, the BR system was better than CSR at removing N from the soil and maintaining low NO−3–N concentrations below the rooting zone.
Influence of Plant Age and Size on Simazine Toxicity and Uptake
Authors: Knuteson S. L. , Whitwell T. , Klaine S. J. 
Published: June 2010

ABSTRACTImproper pesticide management can lead to environmental problems such as water quality degradation and ecological stress. Recent research in our laboratory has focused on development of constructed wetlands to assimilate pesticide‐contaminated water. For improved aesthetics, these wetlands have been established with ornamental plant species. The effectiveness of a plant species for phytoremediation depends in part on its tolerance for the contaminant. Plant tolerance for pesticides may vary depending on plant age and size. This study examined the influence of plant age and size on the uptake, distribution, and toxicity of the herbicide simazine [2‐chloro‐4,6‐bis(ethylamino)‐1,3,5‐triazine] in two ornamental wetland plants: parrot feather [Myriophyllum aquaticum (Vell.) Verdc.] and canna (Canna × hybrida L. ‘Yellow King Humbert’). Plants of different ages and sizes were exposed to simazine in 10% Hoagland's nutrient solution. Toxicity was characterized using plant growth, water uptake, and photosynthetic yield during exposure and postexposure periods. In addition, other plants were exposed to [14C] simazine in nutrient medium to characterize pesticide uptake and translocation. Four‐week‐old parrot feather and canna were more tolerant of simazine than two‐week‐old plants. The two‐week‐old plant tissues of both species had higher tissue burdens of simazine than four‐week‐old plants. Simazine was primarily accumulated in the leaves of both parrot feather and canna. These results suggest that plants in a constructed wetland designed for simazine assimilation would be more vulnerable to simazine toxicity shortly after emergence.
Evaluation of Commercial Odor Control Agents for Suppressing Escherichia coli in Swine Manure Slurry
Authors: Johnston Della , Chapman Ralph , Massé Daniel , Topp Edward 
Published: June 2010

ABSTRACTTen commercially available manure odor control agents were evaluated in bench‐scale laboratory microcosms for their ability to inhibit or kill Escherichia coli, a commonly used indicator of fecal pollution and a potential pathogen. At manufacturer recommended rates, none of the agents reduced viable populations of E. coli in pure cultures or in swine manure slurry. However, at rates 10‐fold higher than those recommended by the manufacturer, EnviroPur rapidly reduced viable populations of E. coli Accelerated death of E. coli was observed at temperatures as low as 4°C. Chemical analysis of EnviroPur indicated that it contains alkylphenol polyethoxylates, common industrial surfactants. These results suggest that at manufacturer‐recommended rates, the odor‐controlling agents would not be effective at suppressing E. coli in stored swine manure slurry.
Phosphorus Loss to Runoff Water Twenty‐Four Hours after Application of Liquid Swine Manure or Fertilizer
Authors: Tabbara Hadi 
Published: June 2010

ABSTRACTPhosphorus (P) added to soil from fertilizer or manure application could pose a threat to water quality due to its role in eutrophication of fresh water resources. Incorporating such amendments into the soil is an established best management practice (BMP) for reducing soluble P losses in runoff water, but could also lead to higher erosion. The objective of this study was to test whether incorporation of manure or fertilizer 24 h before an intense rain could also reduce sediment‐bound and total phosphorus (TP) losses in runoff. A rainfall simulation study was conducted on field plots (sandy loam with 6–7% slope, little surface residue, recently cultivated) that received two application rates of liquid swine manure or liquid ammonium polyphosphate fertilizer, using either surface‐broadcast or incorporated methods of application. Incorporation increased the total suspended solids (TSS) concentrations in runoff but mass losses were not affected. Incorporation also reduced flow‐weighted concentrations and losses of dissolved reactive phosphorus (DRP) and TP by as much as 30 to 60% depending on source (fertilizer vs. manure) and application rate. Phosphorus is moved below the mixing zone of interaction on incorporation, and thus the effect of the amount and availability of P in this zone is more important than cultivation on subsequent P losses in runoff. Incorporating manure or fertilizer in areas of intense erosive rain, recent extensive tillage, and with little or no surface residue is therefore a best management practice that should be adhered to in order to minimize contamination of surface water. Results also show comparatively lower P losses from manure than fertilizer.
Effect of Broadcast Manure on Runoff Phosphorus Concentrations over Successive Rainfall Events
Authors: Kleinman Peter J. A. , Sharpley Andrew N. 
Published: June 2010

ABSTRACTConcern over eutrophication has directed attention to manure management effects on phosphorus (P) loss in runoff. This study evaluates the effects of manure application rate and type on runoff P concentrations from two, acidic agricultural soils over successive runoff events. Soils were packed into 100‐ × 20‐ × 5‐cm runoff boxes and broadcast with three manures (dairy, Bos taurus; layer poultry, Gallus gallus; swine, Sus scrofa) at six rates, from 0 to 150 kg total phosphorus (TP) ha−1 Simulated rainfall (70 mm h−1) was applied until 30 min of runoff was collected 3, 10, and 24 d after manure application. Application rate was related to runoff P (r2 = 0.50–0.98), due to increased concentrations of dissolved reactive phosphorus (DRP) in runoff; as application rate increased, so did the contribution of DRP to runoff TP. Varied concentrations of water‐extractable phosphorus (WEP) in manures (2–8 g WEP kg−1) resulted in significantly lower DRP concentrations in runoff from dairy manure treatments (0.4–2.2 mg DRP L−1) than from poultry (0.3–32.5 mg DRP L−1) and swine manure treatments (0.3–22.7 mg DRP L−1). Differences in runoff DRP concentrations related to manure type and application rate were diminished by repeated rainfall events, probably as a result of manure P translocation into the soil and removal of applied P by runoff. Differential erosion of broadcast manure caused significant differences in runoff TP concentrations between soils. Results highlight the important, but transient, role of soluble P in manure on runoff P, and point to the interactive effects of management and soils on runoff P losses.
Studies on Mobility and Degradation Pathways of Terbuthylazine Using Lysimeters on a Field Scale
Authors: Guzzella L. , Rullo S. , Pozzoni F. , Giuliano G. 
Published: June 2010

ABSTRACTTerbuthylazine [N2‐tert‐butyl‐6‐chloro‐N4‐ethyl‐1,3,5‐triazine‐2,4‐diamine] degradation pathways in agricultural soils were evaluated by following the appearance and mobility of its main transformation products: dealkylated and hydroxylated derivatives. Three experimental degradation studies in open field were performed in different hydraulic conditions: constant hydraulic head on topsoil, achieved to simulate the highest‐risk situation for the aquifer; intermittent artificial precipitation to simulate a medium‐risk situation; and natural precipitation to reproduce the lowest‐risk condition. Concentrations of terbuthylazine transformation products derived from dealkylation and hydroxylation reactions were measured in leachates and soil samples collected during the three experiments. Desethylterbuthylazine (DET) and deethylterbuthylazine‐2‐hydroxide [DETH; 4‐amino‐6‐terbutylamino‐(1,3,5)‐triazine‐2‐OH] were found to be the highest‐leaching compounds and therefore can be considered as potential pollutants for aquifer contamination.
Weed Seed Viability in Composted Beef Cattle Feedlot Manure
Authors: Larney Francis J. , Blackshaw Robert E. 
Published: June 2010

ABSTRACTManure composting has gained increased acceptance by the beef cattle (Bos taurus) feedlot industry in southern Alberta, Canada. Unlike fresh manure, compost is often promoted as being “weed‐free.” Studies were conducted with five weed species in 1997 and thirteen in 1999 to examine the effect of feedlot manure composting on weed seed viability. Weed seeds were buried in open‐air compost windrows and recovered at various times during the thermophilic phase of composting. Windrow temperature and water contents were also measured. Germinability was zero for all composted weed seeds at all sampling times in 1997. However, some seeds remained viable (positive tetrazolium test denoting respiration) on Day 70. In 1999, only one of the thirteen species retained germinability on Day 21 and only two species had respiring seeds on Day 42. Time–viability relationships during composting were defined by exponential decay models. Lethal temperatures to eliminate viability was species‐dependent. In 1999, four weed species were killed in the initial 7 d of composting at a lethal temperature of 39°C while temperatures of >60°C were required for two species. Regression analysis on weed seed viability versus windrow temperature resulted in significant R2 values, which showed that only 17 to 29% of the variation in viability was accounted for by temperature. The lack of definitive relationships between temperature and weed seed viability demonstrated that factors other than temperature may play a role in eliminating weed seeds during composting.
Mineralization of Soil‐Aged Isoproturon and Isoproturon Metabolites by Sphingomonas sp. Strain SRS2
Authors: Johannesen Helle , S⊘rensen Sebastian R. , Aamand Jens 
Published: June 2010

ABSTRACTThe aim of the study was to determine the effect of aging of the herbicide isoproturon and its metabolites monodesmethyl‐isoproturon and 4‐isopropyl‐aniline in agricultural soil on their availability to the degrading bacterium Sphingomonas sp. strain SRS2. The 14C‐ring‐labeled isoproturon, monodesmethyl‐isoproturon, and 4‐isopropyl‐aniline were added to sterilized soil and stored for 1, 49, 71, or 131 d before inoculation with strain SRS2. The availability of the compounds was estimated from the initial mineralization and the amount of 14CO2 recovered after 120 d of incubation. Aging in soil for 131 d reduced the initial mineralization of isoproturon and monodesmethyl‐isoproturon and, in the case of isoproturon, also reduced the recovery of 14CO2 Initial mineralization and recovery of 14CO2 from aged 4‐isopropyl‐aniline were slightly reduced, but less 14CO2 was generally produced than with isoproturon or monodesmethyl‐isoproturon. Thus, recovery of 14CO2 from 14C‐isoproturon and 14C‐monodesmethyl‐isoproturon was 50.7 to 64.4% of the initially added 14C, while recovery from 14C‐4‐isopropyl‐aniline was only 11.7 to 17.0%. Sorption measurements revealed similar Freundlich constants (Kf) for isoproturon and monodesmethyl‐isoproturon, whereas Kf for 4‐isopropyl‐aniline was more than fivefold greater. The findings imply that in soil, partial degradation of isoproturon to 4‐isopropyl‐aniline may lead to reduced mineralization of the herbicide due to sorption of the aniline moiety.
Comparison of Triticonazole Dissipation after Seed or Soil Treatment
Authors: Börjesson Elisabet , Stenström John , Johnsson Lennart , Torstensson Lennart 
Published: June 2010

ABSTRACTThis study examined the long‐term fate of the fungicide triticonazole (TTZ; 5‐[(4‐chlorophenyl)methylene]‐2,2‐dimethyl‐1‐(1H‐1,2,4‐triazol‐1‐ylmethyl)cyclopentanol) applied at a normal field dose (8.9 g ha−1) via seed treatment, which is the normal alternative in practice. The TTZ was applied to wheat (Triticum aestivum L.) grains as a disinfectant before sowing or spraying on bare soil for comparison and reference to the seed treatment. The seeds were germinated and grown in pots in a greenhouse at 22 ± 3°C. The dissipation of TTZ was studied by gas chromatography–mass spectrometry (GC–MS) analysis of the residues every fourth week until no TTZ could be detected. The recovery for analysis of TTZ in soil was between 98 and 131%, and the quantification level was 0.002 mg kg−1 After 56 d of incubation, 20 and 28% of the TTZ applied remained in the soil and seed treatments, respectively, with corresponding half‐lives of 27 and 29 d. The microbial biomass initially decreased in the soil treatment but had recovered after 56 d. The active part of the biomass was not changed during the experimental time. Thus, with respect to dissipation of TTZ and its effect on the soil microbial biomass and activity, no long‐lasting difference between soil and seed treatments could be found.
Environmental Cadmium Levels Increase Phytochelatin and Glutathione in Lettuce Grown in a Chelator‐Buffered Nutrient Solution
Authors: Maier Elizabeth A. , Matthews Rosalyn D. , McDowell Jennifer A. , Walden Rebecca R. , Ahner Beth A. 
Published: June 2010

ABSTRACTPhytochelatins are enzymatically synthesized peptides involved in metal detoxification and have been measured in plants grown at very high Cd concentrations, but few studies have examined the response of plants at lower environmentally relevant Cd concentrations. Using an ethylenediaminetetraacetic acid (EDTA)–buffered nutrient medium, we have varied Cd exposure and measured phytochelatin and glutathione concentrations in romaine lettuce (Lactuca sativa L. var. longifolia Lam. var. Parris Island) grown in a flow‐through hydroponic (FTH) system. Very low free ionic Cd (10−9.6 M) increased average phytochelatin concentrations above those of controls, and increasing Cd resulted in increased phytochelatin production, though increases were tissue dependent. Glutathione concentrations also increased with increasing Cd. In other standard hydroponic experiments, the media were manipulated to vary total Cd concentration while the ionic Cd was fixed. We found that the total amount of Cd (primarily EDTA bound) in the medium altered thiol production in roots, whereas thiols in leaves remained constant. The Cd uptake into roots and translocation to old leaves was also influenced by the total concentration in the medium. Cadmium in all tissues was lower and in some tissues thiol concentrations were higher than in FTH‐grown plants grown in identical medium, suggesting that nutrient delivery technique is also an important variable. Though phytochelatin and glutathione production can be sensitive to changes in bioavailable Cd, thiol concentrations will not necessarily reflect the Cd content of the plant tissues.
Phosphorus Runoff Relationships for Louisiana Coastal Plain Soils Amended with Poultry Litter
Authors: Gaston Lewis A. , Drapcho Caye M. , Tapadar Soma , Kovar John L. 
Published: June 2010

ABSTRACTLong‐term application of poultry (Gallus gallus domesticus) litter has built high levels of P in certain Coastal Plain soils of north Louisiana. However, soil P/runoff P relationships for soil and environmental conditions of the area have not been examined. This study measured soil P (total, Bray 1, Bray 2, Mehlich 3, resin‐exchangeable, and water‐extractable) and runoff P (dissolved P, DP; and total P, TP) at four pasture sites previously amended with poultry litter. Sites varied in soil P due to annual litter applications ranging from 1 to more than 20. Three replicated plots at each site were subjected to simulated rainfalls over 2 yr, and concentrations of DP and TP in runoff were measured and related to soil P. This allowed examination of soil P/runoff P relationships and their changes over time. Runoff DP was also related to DP desorbed from surface soil in a miscible displacement experiment. Among measures of soil P, only resin‐exchangeable and water‐extractable P showed significant decreases over 2 yr. These measures of soil P explained 54 to 64% of the variability in runoff DP data. However, the miscible displacement technique proved the best indicator of runoff DP, explaining 70% of the variability. Runoff varied among sites (decreasing with increasing years of litter application), limiting the predictive capability of the soil extraction methods. Linking runoff characteristics with miscible displacement data may be a useful predictive tool and warrants further examination.
Long‐Term Effects of Clipping and Nitrogen Management in Turfgrass on Soil Organic Carbon and Nitrogen Dynamics
Authors: Qian Y. L. , Bandaranayake W. , Parton W. J. , Mecham B. , Harivandi M. A. , Mosier A. R. 
Published: June 2010

ABSTRACTExperiments to document the long‐term effects of clipping management on N requirements, soil organic carbon (SOC), and soil organic nitrogen (SON) are difficult and costly and therefore few. The CENTURY ecosystem model offers an opportunity to study long‐term effects of turfgrass clipping management on biomass production, N requirements, SOC and SON, and N leaching through computer simulation. In this study, the model was verified by comparing CENTURY‐predicted Kentucky bluegrass (Poa pratensis L.) clipping yields with field‐measured clipping yields. Long‐term simulations were run for Kentucky bluegrass grown under home lawn conditions on a clay loam soil in Colorado. The model predicted that compared with clipping‐removed management, returning clippings for 10 to 50 yr would increase soil C sequestration by 11 to 25% and nitrogen sequestration by 12 to 28% under a high (150 kg N ha−1 yr−1) nitrogen (N) fertilization regime, and increase soil carbon sequestration by 11 to 59% and N sequestration by 14 to 78% under a low (75 kg N ha−1 yr−1) N fertilization regime. The CENTURY model was further used as a management supporting system to generate optimal N fertilization rates as a function of turfgrass age. Returning grass clippings to the turf–soil ecosystem can reduce N requirements by 25% from 1 to 10 yr after turf establishment, by 33% 11 to 25 yr after establishment, by 50% 25 to 50 yr after establishment, and by 60% thereafter. The CENTURY model shows potential for use as a decision‐supporting tool for maintaining turf quality and minimizing negative environmental impacts.
Manure History and Long‐Term Tillage Effects on Soil Properties and Phosphorus Losses in Runoff
Authors: Andraski Todd W. , Bundy Larry G. , Kilian Kenneth C. 
Published: June 2010

ABSTRACTManure additions to cropland can reduce total P losses in runoff on well‐drained soils due to increased infiltration and reduced soil erosion. Surface residue management in subsequent years may influence the long‐term risk of P losses as the manure‐supplied organic matter decomposes. The effects of manure history and long‐term (8‐yr) tillage [chisel plow (CP) and no‐till (NT)] on P levels in runoff in continuous corn (Zea mays L.) were investigated on well‐drained silt loam soils of southern and southwestern Wisconsin. Soil P levels (0–15 cm) increased with the frequency of manure applications and P stratification was greater near the surface (0–5 cm) in NT than CP. In CP, soil test P level was linearly related to dissolved P (24–105 g ha−1) and bioavailable P (64–272 g ha−1) loads in runoff, but not total P (653–1893 g ha−1). In NT, P loads were reduced by an average of 57% for dissolved P, 70% for bioavailable P, and 91% for total P compared with CP. This reduction was due to lower sediment concentrations and/or lower runoff volumes in NT. There was no relationship between soil test P levels and runoff P concentrations or loads in NT. Long‐term manure P applications in excess of P removal by corn in CP systems ultimately increased the potential for greater dissolved and bioavailable P losses in runoff by increasing soil P levels. Maintaining high surface residue cover such as those found in long‐term NT corn production systems can mitigate this risk in addition to reducing sediment and particulate P losses.