bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated BIosphere Simulator (IBIS) Yield and Nitrate Loss Predictions for Wisconsin Maize Receiving Varied Amounts of Nitrogen Fertilizer
Authors: Kucharik Christopher J. , Brye Kristofor R. 
Published: August 2012

ABSTRACTAgriculture in the U.S. Midwest faces the formidable challenge of improving crop productivity while simultaneously mitigating the environmental consequences of intense management. This study examined the simultaneous response of nitrate nitrogen (NO3–N) leaching losses and maize (Zea mays L.) yield to varied fertilizer N management using field observations and the Integrated BIosphere Simulator (IBIS) model. The model was validated against six years of field observations in chisel‐plowed maize plots receiving an optimal (180 kg N ha−1) fertilizer N application and in N‐unfertilized plots on a silt loam soil near Arlington, Wisconsin. Predicted values of grain yield, harvest index, plant N uptake, residue C to N ratio, leaf area index (LAI), grain N, and drainage were within 20% of observations. However, simulated NO3–N leaching losses, NO3–N concentrations, and net N mineralization exhibited less interannual variability than observations, and had higher levels of error (20–65%). Potential effects of 30% higher (234 kg N ha−1) and 30% lower (126 kg N ha−1) fertilizer N use (from optimal) on NO3–N leaching loss and maize yield were simulated. A 30% increase in fertilizer N use increased annual NO3–N leaching by 56%, while yield increased by only 1%. The NO3–N concentration in the leachate solution at 1.4 m below the soil surface was 30.7 mg L−1 When fertilizer N use was reduced by 30% (from optimal), annual NO3–N leaching losses declined by 42% after seven years, and annual average yield only decreased by 8%. However, NO3–N concentration in the leachate solution remained above 10 mg L−1 (11.3 mg L−1). Clearly, nonlinear relationships existed between changes in fertilizer use and NO3–N leaching losses over time. Simulated changes in NO3–N leaching were greater in magnitude than fertilizer N use changes.
Methane Emissions of Beef Cattle on Forages
Authors: DeRamus H. Alan , Clement Terry C. , Giampola Dean D. , Dickison Peter C. 
Published: August 2012

ABSTRACTFermentation in the rumen of cattle produces methane (CH4). Methane may play a role in global warming scenarios. The linking of grazing management strategies to more efficient beef production while reducing the CH4 emitted by beef cattle is important. The sulfur hexafluoride (SF6) tracer technique was used to determine the effects of best management practices (BMP) grazing compared with continuous grazing on CH4 production in several Louisiana forages during 1996–1998. Cows and heifers (Bos taurus) grazed common bermudagrass [Cynodon dactylon (L.) Pers.], bahiagrass (Paspalum notatum Flugge), and ryegrass (Lolium multiflorum Lam.) pastures and were wintered on bahiagrass hay with supplements of protein molasses blocks (PMB), cottonseed meal and corn (CSMC), urea and corn (URC), or limited ryegrass grazing (LRG). Daily CH4 emissions were between 89 and 180 g d−1 for young growing heifers and 165 to 294 g d−1 for mature Simbrah cows. Heifers on “ad lib” ryegrass in March and April produced only one‐tenth the CH4 per kg of gain as heifers on LRG of 1 h. Using BMP significantly reduced the emission of CH4 per unit of animal weight gain. Management‐intensive grazing (MIG) is a BMP that offers the potential for more efficient utilization of grazed forage crops via controlled rotational grazing and more efficient conversion of forage into meat and milk. Projected CH4 annual emissions in cows reflect a 22% reduction from BMP when compared with continuous grazing in this study. With the BMP application of MIG, less methane was produced per kilogram of beef gain.
Evaluation of Attachment ofCryptosporidium parvumandGiardia lambliato Soil Particles
Authors: Dai Xin , Boll Jan 
Published: August 2012

ABSTRACTTransport ofCryptosporidium parvumoocysts andGiardia lambliacysts in the aquatic environment is poorly understood. Information about their transport is essential for actual risk assessment and development of effective control practices. Several studies have suggested that attachment to soil particles is not likely to occur, but the hypothesis has not been well tested, partly because enumeration ofC. parvumoocysts orG. lambliacysts [written as (oo)cysts] in the presence of soil has been difficult. In this paper, a combination of flow cytometry, and epifluorescence and confocal microscopy was successfully used to enumerate (oo)cysts in the presence of soil and determine whether (oo)cysts travel freely in water or attached to soil particles. The maximum soil concentration in water samples for reliable enumeration of (oo)cysts was 2 mg/L. Particle attachment experiments detected attached pairs of oppositely charged beads and (oo)cysts, while no attachment was observed between like charged beads, (oo)cysts, and soil particles. These results support the hypothesis that electrostatic forces govern the interaction between (oo)cysts and soil particles. Batch experiments further confirmed the null hypothesis (p> 0.05) that (oo)cysts do not attach to natural soil particles. These findings suggest that, when (oo)cysts have been entrained in overland flow (i.e., runoff), they will travel freely in the water and not as part of the particulate sediment load.
Putative Temporal Variability of Escherichia coli Ribotypes from Yearling Steers
Authors: Jenkins M. B. , Hartel P. G. , Olexa T. J. , Stuedemann J. A. 
Published: August 2012

ABSTRACTEscherichia coli is a ubiquitous component of the intestinal microflora of warm‐blooded animals, and is an indicator of fecal contamination of surface waters. Ribotype profiling of E. coli is one of several genotypic methods that has been developed to determine the host origin of fecal bacteria. Like most genotypic methods of source tracking, ribotyping requires a host origin database to identify environmental isolates. To determine the extent of temporal variability of ribotypes and its effect on a host origin database, E. coli isolates were obtained from fecal samples of two herds of Black Angus steers at a long‐term experimental site at four sampling times from October 1999 to July 2000. Fecal samples were taken from six randomly chosen steers at each time. At a similarity index of 90% as calculated by unweighted pair‐group method using arithmetic averages (UPGMA), 240 ribotypes were identified from 451 E. coli isolates. Only 20 ribotypes (8.3%), comprising 33% of the total isolates, were shared among sampling times and were considered resident ribotypes. Two of the twenty resident ribotypes appeared at three sampling times, and the remaining eighteen appeared at two. The majority of the ribotypes, therefore, were transient and unique to each sampling time and steer. Both the apparent turnover of E. coli ribotypes and a clonal diversity index of 0.97 (indicative of extensive ribotype variability) suggest the necessity of ribotyping a large number E. coli isolates per host to establish a host origin database that is independent of temporal variability, or complete enough to be effective.
Relationships between Phosphorus Levels in Soil and in Runoff from Corn Production Systems
Authors: Andraski Todd W. , Bundy Larry G. 
Published: August 2012

ABSTRACTPhosphorus‐enriched runoff from cropland can hasten eutrophication of surface waters. A soil P level exceeding crop needs due to long‐term fertilizer and/or manure applications is one of several potential sources of increased P losses in runoff from agricultural systems. Field experiments were conducted at locations representative of three major soil regions in Wisconsin in corn (Zea mays L.) production systems to determine the effect of tillage, recent manure additions, soil P extraction method, and soil sampling depth (0–2, 0–5, and 0–15 cm) on the relationship between soil test P level and P concentrations in runoff. Runoff from simulated rainfall (75 mm h−1) was collected from 0.83‐m2 areas for 1 h after rainfall initiation and analyzed for dissolved phosphorus (DP), total phosphorus (TP), and sediment. The DP fraction of the TP concentration in runoff ranged from 5 to 17% among sites with most of the variation in TP due to varying sediment concentration on the well‐drained silt loam soils and to soil test P level on the poorly drained silty clay loam soil. In 213 observations across a range of soils and managements, good relationships occurred between soil test P level and DP concentration in runoff for most of the tests and sampling depths used. Recent manure additions and high levels of surface cover from corn residue sometimes masked this relationship. The slope of DP relative to soil test P level was markedly higher on the silty clay loam soil than on the silt loam soils possibly due to soil permeability–infiltration rate differences. Agronomic soil P tests were as effective as environmentally oriented soil P tests for predicting DP concentrations in runoff.
Patterns of Short‐Term Sedimentation in a Freshwater Created Marsh
Authors: Harter Sarah K. , Mitsch William J. 
Published: August 2012

ABSTRACTThis study investigated different sedimentation measurement techniques and examined patterns of short‐term sedimentation in two 1‐ha replicate created freshwater marshes in central Ohio, USA. Short‐term (one‐year) sediment accumulation above feldspar, clay, glitter, and sand artificial marker horizons was compared at different water depths and distances from wetland inflow. A sediment budget was also constructed from turbidity and suspended sediment data for comparison with marker horizons. Glitter and sand marker horizons were the most successful for measuring sediment accumulation (81–100% marker recovery), while clay markers were completely unsuccessful. The sedimentation rate for both wetlands averaged 4.9 cm yr−1 (36 kg m−2 yr−1), and ranged from 1.82 to 9.23 cm yr−1 (12.4 to 69.7 kg m−2 yr−1). Sedimentation rates in deep, open water areas were significantly higher than in shallow, vegetated areas for both wetlands (t test, p < 0.05). However, observed sedimentation patterns may be attributed more to preferential flow through open water areas than to water depth or presence of vegetation. Contrary to the expected spatial distribution, sedimentation was highly variable within the wetlands, suggesting that bioturbation and turbulence may cause significant resuspension or that high hydrologic loads may distribute sediments throughout the basins. A sediment budget estimated sediment retention of approximately 740 g m−2 yr−1 per wetland (43% removal rate), yet gross sediment accumulation was 36 000 g m−2 yr−1 measured by marker horizons. These results suggest that erosive forces may have influenced sedimentation, but also may indicate problems with the sediment budget calculation methodology.
Spatial Analysis of Phosphorus Sorption Capacity in a Semiarid Altered Wetland
Authors: Litaor M. I. , Reichmann O. , Belzer M. , Auerswald K. , Nishri A. , Shenker M. 
Published: August 2012

ABSTRACTThe observed increase in phosphorus (P) loading into the Jordan River could increase eutrophication processes in Lake Kinneret, the only freshwater lake in Israel, which provides 25% of the country's drinking water. The P may originate from the peat soils of the highly altered Hula Valley's semiarid wetland ecosystem through which the Jordan River runs. The objectives of this research were to ascertain the sorption capacity of these soils and to identify areas with high potential for P release from soils to ground water. We extracted 80 soil samples collected across the valley with ammonium oxalate and determined the ratio of extractable P to Fe and Al, from which we derived the degree of phosphorus saturation (DPS). A relatively low DPS (<15%) was observed in Histosols compared with the high DPS (>30%) observed in many of the hydromorphic organo–mineral soils. We used a sequential Gaussian simulation technique to assess the spatial pattern of the DPS and found that the Histosols have a low probability (<10%) of exceeding the widely used environmental DPS threshold of 25%. The areas characterized by mineral soils, such as hydromorphic Vertisols and various marl redoximorphic soils, have a high probability (>60%) of exceeding the threshold value. The ability to predict the concentrations of dissolved P in ground water based on DPS values was somewhat impaired because of the preferential flow characteristics in this altered wetland.
Enumeration of Waterborne Escherichia coli with Petrifilm Plates
Authors: Vail J. H. , Morgan R. , Merino C. R. , Gonzales F. , Miller R. , Ram J. L. 
Published: August 2012

ABSTRACTEscherichia coli is often monitored in environmental waters as an indicator of the possible presence of human pathogens associated with feces. Petrifilm E. coli/coliform count plates (3M, Minneapolis, MN), previously validated for enumerating E. coli in food, were tested for monitoring E. coli in environmental water. Escherichia coli counts in environmental water samples enumerated with Petrifilm were significantly correlated (R > 0.9; slope = 0.9–1.0; p < 0.001) with counts obtained with three commonly used methods, mTEC (Becton Dickinson, Sparks, MD), m‐ColiBlue (Hach, Loveland, CO), and Colilert‐18/IDEXX Quanti‐Tray 2000 (IDEXX, Westbrook, ME). Blue colonies on Petrifilm plates were most reliably identified as E. coli when accompanied by gas formation, as determined by characterization of the colonies on MacConkey agar plates (PML Microbiologicals, Mississauga, ON, Canada) and by polymerase chair reaction (PCR) with E. coli–specific primers. The main disadvantage of Petrifilm plates for environmental water testing is the small volume (1 mL per sample) that can be tested; however, the plates appear to be suitable for screening and locating sites that exceed criteria for total body and partial body contact. Simplicity of use and storage, reliability, and relatively low cost make Petrifilm plates suitable for volunteer‐based and educational water quality monitoring applications, particularly when used as a preliminary screening method to identify problem sites.
Pathogen Survival in Swine Manure Environments and Transmission of Human Enteric Illness—A Review
Authors: Guan Tat Yee , Holley Richard A. 
Published: August 2012

ABSTRACTThe influence of zoonotic pathogens in animal manure on human health and well‐being as a direct or indirect cause of human enteric illness is examined. Available international data are considered, but the study is focused on the developing situation in western Canada, where it is certain there will be further rapid growth in livestock numbers, particularly hogs. Major pathogens considered are Escherichia coli O157:H7, Salmonella, Campylobacter, Yersinia, Cryptosporidium, and Giardia Canada is now the leading exporter of pork internationally, but recent increases in production contrast with constant domestic levels of pork consumption and declining levels of foodborne illness caused by pork. Effects of increased levels of manure production are not quantifiable in terms of effects on human health. The presence of major pathogens in manure and movement to human food sources and water are considered on the basis of available data. Survival of the organisms in soil, manure, and water indicate significant variability in resistance to environmental challenge that are characteristic of the organisms themselves. Generally, pathogens survived longer in environmental samples at cool temperatures but differences were seen in liquid and solid manure. Based on actual data plus some data extrapolated from cattle manure environments, holding manure at 25°C for 90 d will render it free from the pathogens considered above.
Transport and Biodegradation of Perchlorate in Soils
Authors: Tipton Deborah K. , Rolston Dennis E. , Scow Kate M. 
Published: August 2012

ABSTRACTPerchlorate (ClO−4) contamination of ground water and surface water is a widespread problem, particularly in the western United States. This study examined the effect of biodegradation on perchlorate fate and transport in soils. Solute transport experiments were conducted on two surface soils. Pulses of solution containing perchlorate and Br− were applied to saturated soil columns at steady state water flow. Perchlorate behaved like a nonreactive tracer in Columbia loam (coarse‐loamy, mixed, superactive, nonacid, thermic Oxyaquic Xerofluvent) but was degraded in Yolo loam (fine‐silty, mixed, superactive, nonacid, thermic Mollic Xerofluvent). Batch experiments demonstrated that perchlorate removal from solution in Yolo loam was caused by biodegradation. Other batch experiments with Yolo loam surface and subsurface soils, Columbia loam surface soil, and dredge tailings demonstrated that perchlorate biodegradation required anaerobic conditions, an adequate carbon source, and an active perchlorate‐degrading microbial population. The sequential reduction of perchlorate and NO−3 by an indigenous soil microbial community in Yolo loam batch systems was also studied. Nitrate reduction occurred much sooner than perchlorate reduction in soils that had not been previously exposed to perchlorate, but NO−3 and perchlorate were simultaneously reduced in soils previously exposed to perchlorate. The results of this study have implications for in situ remediation schemes and for agricultural soils that have been contaminated by perchlorate‐tainted irrigation water.
Odor and Gas Release from Anaerobic Treatment Lagoons for Swine Manure
Authors: Lim Teng‐Teeh , Heber Albert J. , Ni Ji‐Qin , Sutton Alan L. , Shao Ping 
Published: August 2012

ABSTRACTOdor and gas release from anaerobic lagoons for treating swine waste affect air quality in neighboring communities but rates of release are not well documented. A buoyant convective flux chamber (BCFC) was used to determine the effect of lagoon loading rate on measured odor and gas releases from two primary lagoons at a simulated wind speed of 1.0 m s−1 Concentrations of ammonia (NH3), hydrogen sulfide (H2S), carbon dioxide (CO2), sulfur dioxide (SO2), and nitric oxide (NO) in 50‐L air samples were measured. A panel of human subjects, whose sensitivity was verified with a certified reference odorant, evaluated odor concentration, intensity, and hedonic tone. Geometric mean odor concentrations of BCFC inlet and outlet samples and of downwind berm samples were 168 ± 44 (mean ± 95% confidence interval), 262 ± 60, and 114 ± 38 OUE m−3 (OUE, European odor unit, equivalent to 123 μg n‐butanol), respectively. The overall geometric mean odor release was 2.3 ± 1.5 OUE s−1 m−2 (1.5 ± 0.9 OU s−1 m−2). The live mass specific geometric mean odor release was 13.5 OUE s−1 AU−1 (animal unit = 500 kg live body mass). Overall mean NH3, H2S, CO2 and SO2 releases were 101 ± 24, 5.7 ± 2.0, 852 ± 307, and 0.5 ± 0.4 μg s−1 m−2, respectively. Nitric oxide was not detected. Odor concentrations were directly proportional to H2S and CO2 concentrations and odor intensity, and inversely proportional to hedonic tone and SO2 concentration (P < 0.05). Releases of NH3, H2S, and CO2 were directly proportional (P < 0.05) to volatile solids loading rate (VSLR).
Polycyclic Aromatic Hydrocarbons (PAHs) and Estrogenic Compounds in Experimental Flue Gas Streams
Authors: Muthumbi W. , De Boever P. , Pieters J. G. , Siciliano S. , D'Hooge W. , Verstraete W. 
Published: August 2012

ABSTRACTThe importance of combustion processes as a source of substances with estrogenic activity in the environment was investigated. Wood (nontreated and treated with wood preservatives), barbecue charcoal, meat, and kitchen waste were combusted in a laboratory‐scale incinerator. Flue gas emissions (particulates and gaseous pollutants) were trapped in polyurethane foam cartridges. The cartridges were subjected to Soxhlet extraction and part of the extracts redissolved in dimethylsulfoxide (DMSO) for analyses of estrogenic activity by means of the yeast‐based human estrogen receptor (hER) bioassay. A synthetic estrogen, 17‐α‐ethinylestradiol (EE2), was used as the reference estrogenic compound. Part of the extracts was analyzed for the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs). Estrogenic compounds in the flue gas (wood) were as high as 234 ± 25 ng m−3 EE2 equivalent compared with 27 to 81 ng m−3 EE2 equivalent in flue gas from combustion of barbecue charcoal. Concentrations of polycyclic aromatic hydrocarbons in both flue gas streams were in the range of 21 000 ± 2000 and 240 ± 110 ng m−3, respectively. In general, the concentrations of EE2 equivalent in the flue gas samples were at least a factor of 1000 lower than total PAH concentration. The EE2 levels were not related to the concentration of PAHs in any flue gas sample.
Nitrous Oxide, Nitric Oxide, and Nitrogen Dioxide Fluxes from Soils after Manure and Urea Application
Authors: Akiyama Hiroko , Tsuruta Haruo 
Published: August 2012

ABSTRACTNitrous oxide is a greenhouse gas, and NO and NO2 play a key role in atmospheric chemistry. Nitrous oxide, NO, and NO2 fluxes from fertilized soils were measured six times per day by an automated flux monitoring system for one year, beginning on 21 May 1998. Pac choi (Brassica spp.) was cultivated for two months, and the plots were left fallow the remainder of the year. Two types of manure, poultry manure (PM) and swine manure (SM), and a chemical fertilizer, urea, were applied to the soil. The total amount of nitrogen applied in each case was 15 g N m−2 The total fluxes from PM, SM, and urea for the year were 184, 61.3, and 44.8 mg N m−2 for N2O, respectively; 9.95, 16.6, and 148 mg N m−2 for NO, respectively; and −6.21, −7.23, and −7.84 mg N m−2 for NO2, respectively. A negative correlation was found between the NO flux and the NO concentration of the chamber air just after the chamber was closed, when a flux from the atmosphere to soil was observed for 10 months. The mean gross NO production, the NO uptake rate constant, and the apparent compensation point for this period were 0.79 to 0.95 μg N m−2 h−1, 120 to 128 L m−2 h−1, and 5.65 to 7.35 ppbv, respectively.