bluuebunny/crossref_metadata_2025_split huggingface dataset:
Release ofCryptosporidiumandGiardiafrom Dairy Cattle Manure
Authors: Schijven Jack F. , Bradford Scott A. , Yang Shihui 
Published: June 2010

ABSTRACTVarious physical factors affecting the release rate of naturally occurringCryptosporidium parvumoocysts andGiardia duodenaliscysts from dairy manure disks to sprinkled water were studied. The investigated factors included temperature (5 or 23°C), manure type (calf manure, a 50% calf and 50% cow manure mixture, and a 10% calf and 90% cow manure mixture), and water application method (mist or drip) and flow rate. Effluent concentrations of manure and (oo)cysts were always several orders of magnitude below their initial concentration in the manure, decreased gradually, and exhibited persistent concentration tailing. Release of manure and (oo)cysts were found to be related by a constant factor, the so‐called release efficiency of (oo)cysts. A previously developed (oo)cyst release model that included these release efficiencies provided a satisfactory simulation of the observed release. An effect of temperature on the release of manure and (oo)cysts was not apparent. The manure and (oo)cyst release rates from cow manure decreased faster than those from calf manure, and (oo)cyst release efficiencies from cow manure were higher than those from calf manure. In comparison with mist application, dripping water resulted in higher release rates of manure and (oo)cysts and in higher (oo)cyst release efficiencies due to the increased mechanical forces associated with droplet impact. Mist application at a higher flow rate resulted in faster release, but did not affect the (oo)cyst release efficiencies. The data and modeling approach described herein provide insight and an enhanced ability to describe the influence of physical factors on (oo)cyst release.
Nitrogen Availability from Composts for Humid Region Perennial Grass and Legume–Grass Forage Production
Authors: Lynch D. H. , Voroney R. P. , Warman P. R. 
Published: June 2010

ABSTRACTPerennial forages may be ideally suited for fertilization with slow N release amendments such as composts, but difficulties in predicting N supply from composts have limited their routine use in forage production. A field study was conducted to compare the yield and protein content of a binary legume–grass forage mixture and a grass monocrop cut twice annually, when fertilized with diverse composts. In all three years from 1998–2000, timothy (Phleum pratenseL.)–red clover (Trifolium pratenseL.) and timothy swards were fertilized with ammonium nitrate (AN) at up to 150 and 300 kg N ha−1yr−1, respectively. Organic amendments, applied at up to 600 kg N ha−1yr−1in the first two years only, included composts derived from crop residue (CSC), dairy manure (DMC), or sewage sludge (SSLC), plus liquid dairy manure (DM). Treatments DM at 150 kg N ha−1yr−1and CSC at 600 kg N ha−1yr−1produced cumulative timothy yields matching those obtained for inorganic fertilizer. Apparent nitrogen recovery (ANR) ranged from 0.65% (SSLC) to 15.1% (DMC) for composts, compared with 29.4% (DM) and 36.5% (AN). The legume component (approximately 30%) of the binary mixture acted as an effective “N buffer” maintaining forage yield and protein content consistently higher, and within a narrower range, across all treatments. Integrating compost utilization into livestock systems that use legume–grass mixtures may reduce the risk of large excesses or deficits of N, moderate against potential losses in crop yield and quality, and by accommodating lower application rates of composts, reduce soil P and K accumulation.
Quantification of the Effect of Fumigation on Short‐ and Long‐Term Nitrogen Mineralization and Nitrification in Different Soils
Authors: De Neve Stefaan , Csitári Gabor , Salomez Joost , Hofman Georges 
Published: June 2010

ABSTRACTThe effect of soil fumigation on N mineralization and nitrification needs to be better quantified to optimize N fertilizer advice and predict NO−3 concentrations in crops and NO−3 leaching risks. Seven soils representing a range in soil texture and organic matter contents were fumigated with Cyanamid DD 95 (a mixture of 1,3‐dichloropropane and 1,3‐dichloropropene). After removal of the fumigant, the fumigated soils and unfumigated controls were incubated for 20 wk and N mineralization and nitrification were monitored by destructive sampling. The average short‐term N mineralization rates (ks) were significantly larger in the fumigated than in the unfumigated soils (P = 0.025), but the differences in ks between fumigated and unfumigated soils could not be related to soil properties. The average long‐term N mineralization rates (kl) were slightly larger in the fumigated soils but the difference with the unfumigated soils was not significant. Again, the differences in kl values could not be related to soil properties. Nitrification was inhibited completely for at least 3 wk in all soils, and an effect on nitrification could be observed up to 17 wk in one soil. An S‐shaped function was fitted to the nitrification data corrected for N mineralization, and both the rate constant (γ) and the time at which maximum nitrification was reached (tmax) were strongly correlated to soil pH. However, since no correlations were found between the effect of fumigation on N mineralization and soil properties, taking into account the effects of fumigation in fertilizer advice and in the prediction of NO−3 leaching risks will need further research.
Phosphorus Loss and Runoff Characteristics in Three Adjacent Agricultural Watersheds with Claypan Soils
Authors: Udawatta Ranjith P. , Motavalli Peter P. , Garrett Harold E. 
Published: June 2010

ABSTRACTEffects of precipitation, runoff, and management on total phosphorus (TP) loss from three adjacent, row‐cropped watersheds in the claypan region of northeastern Missouri were examined from 1991 to 1997 to understand factors affecting P loss in watersheds dominated by claypan soils. Runoff samples from each individual runoff event were analyzed for TP and sediment concentration. The annual TP loss ranged from 0.29 to 3.59 kg ha−1 with a mean of 1.36 kg ha−1 across all the watersheds during the study period. Significantly higher loss of TP from the watersheds was observed during the fallow period. Multiple small runoff events or several large runoff events contributed to loss of TP from the watersheds. Total P loss in 1993, a year with above‐normal precipitation, accounted for 30% of the total TP loss observed over seven years. The five largest runoff events out of a total of 66 events observed over seven years accounted for 27% of the TP loss. The five largest sediment losses were responsible for 24% of the TP loss over seven years. Runoff volume and sediment loss explained 64 to 73% and 47 to 58% of the variation in TP loss on watersheds during the study. Flow duration and maximum flow accounted for 49 and 66% of TP loss, respectively. The results of this study suggest that management practices that reduce runoff volume, flow duration, maximum flow, and sediment loss, and that maintain a suitable vegetative cover throughout the year could lower P loss in claypan soils.
Effects of Mineral Surfaces on Pyrene Partitioning to Well‐Characterized Humic Substances
Authors: Hur Jin , Schlautman Mark A. 
Published: June 2010

ABSTRACTMineral surfaces can alter the ability of humic substances (HS) to bind hydrophobic organic contaminants. In this study, complete adsorption (i.e., to avoid HS adsorptive fractionation effects) of a small subset of well‐characterized terrestrial and aquatic HS on kaolinite and hematite significantly changed their subsequent organic carbon–normalized partition coefficients Kadsoc for pyrene relative to their original respective dissolved organic carbon–normalized partition coefficients Kdisoc Parallel experiments with ultrafiltration (UF) fractions obtained from purified Aldrich humic acid (PAHA) (Aldrich Chemical, Milwaukee, WI) gave similar results. The heterogeneity among the PAHA UF fractions was examined via their mineral surface adsorption characteristics and their subsequent ability to bind pyrene. As expected, variations in maximum adsorption densities (qmax), Langmuir adsorption constants (Kq), and pyrene Kadsoc values were observed among the PAHA UF fractions. However, general trends of qmax, Kq, and pyrene log Kadsoc values for the PAHA UF fractions versus the logarithm of their weight‐average molecular weights (MWw) did not typically match the corresponding trends obtained with the four aquatic and terrestrial HS. In general, an ideal mixture competitive adsorption model gave reasonable predictions for PAHA sorption to kaolinite and hematite based on their corresponding UF isotherm parameters. Ideal mixture predictions of pyrene partitioning to adsorbed PAHA from the corresponding UF fraction results were better for kaolinite versus hematite, indicating that the underlying mineral surface can alter the effects of HS heterogeneity on hydrophobic organic contaminant sorption.
Nitrate Leaching to Subsurface Drains as Affected by Drain Spacing and Changes in Crop Production System
Authors: Kladivko E. J. , Frankenberger J. R. , Jaynes D. B. , Meek D. W. , Jenkinson B. J. , Fausey N. R. 
Published: June 2010

ABSTRACTSubsurface drainage is a beneficial water management practice in poorly drained soils but may also contribute substantial nitrate N loads to surface waters. This paper summarizes results from a 15‐yr drainage study in Indiana that includes three drain spacings (5, 10, and 20 m) managed for 10 yr with chisel tillage in monoculture corn (Zea mays L.) and currently managed under a no‐till corn–soybean [Glycine max (L.) Merr.] rotation. In general, drainflow and nitrate N losses per unit area were greater for narrower drain spacings. Drainflow removed between 8 and 26% of annual rainfall, depending on year and drain spacing. Nitrate N concentrations in drainflow did not vary with spacing, but concentrations have significantly decreased from the beginning to the end of the experiment. Flow‐weighted mean concentrations decreased from 28 mg L−1 in the 1986–1988 period to 8 mg L−1 in the 1997–1999 period. The reduction in concentration was due to both a reduction in fertilizer N rates over the study period and to the addition of a winter cover crop as a “trap crop” after corn in the corn–soybean rotation. Annual nitrate N loads decreased from 38 kg ha−1 in the 1986–1988 period to 15 kg ha−1 in the 1997–1999 period. Most of the nitrate N losses occurred during the fallow season, when most of the drainage occurred. Results of this study underscore the necessity of long‐term research on different soil types and in different climatic zones, to develop appropriate management strategies for both economic crop production and protection of environmental quality.
Rate of Fall‐Applied Liquid Swine Manure
Authors: Gessel P. D. , Hansen N. C. , Moncrief J. F. , Schmitt M. A. 
Published: June 2010

ABSTRACTReducing the delivery of phosphorus (P) from land‐applied manure to surface water is a priority in many watersheds. Manure application rate can be controlled to manage the risk of water quality degradation. The objective of this study was to evaluate how application rate of liquid swine manure affects the transport of sediment and P in runoff. Liquid swine manure was land‐applied and incorporated annually in the fall to runoff plots near Morris, Minnesota. Manure application rates were 0, 0.5, 1, and 2 times the rate recommended to supply P for a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation. Runoff volume, sediment, and P transport from snowmelt and rainfall were monitored for 3 yr. When manure was applied at the highest rate, runoff volume and sediment loss were less than the control plots without manure. Reductions in runoff volume and soil loss were not observed for spring runoff when frozen soil conditions controlled infiltration rates. The reduced runoff and sediment loss from manure amended soils compensated for addition of P, resulting in similar runoff losses of total P among manure application rates. However, losses of dissolved P increased with increasing manure application rate for runoff during the spring thaw period. Evaluation of water quality risks from fall‐applied manure should contrast the potential P losses in snowmelt runoff with the potential that incorporated manure may reduce runoff and soil loss during the summer.
Comparison of Three Enzyme Immunoassays for Measuring 17β‐Estradiol in Flushed Dairy Manure Wastewater
Authors: Hanselman Travis A. , Graetz Donald A. , Wilkie Ann C. 
Published: June 2010

ABSTRACTNatural steroidal estrogens are an environmental concern because low nanogram per liter concentrations in water can adversely affect aquatic vertebrate species by disrupting the normal function of their endocrine systems. There is a critical need to accurately measure estrogens in dairy wastes, a potential source of estrogens such as 17β‐estradiol, to assess the risk of estrogen contamination of agricultural drainage waters resulting from land application. Commercially available enzyme immunoassay (EIA) kits have been used for measuring 17β‐estradiol in livestock manure, but it is not known if different EIAs provide similar results. We compared three EIAs by measuring 17β‐estradiol in two samples of flushed dairy manure wastewater (FDMW). The measured concentrations of 17β‐estradiol in FDMW differed according to the immunoassay used. The differences were attributed to a matrix interference associated with coextracted humic substances. Future research should develop methods that enable routine measurement of 17β‐estradiol in livestock wastes by more conclusive analytical techniques such as gas chromatography–mass spectrometry.
Changes in the Nature of Sewage Sludge Organic Matter During a Twenty‐One‐Month Incubation
Authors: Smernik Ronald J. , Oliver Ian W. , McLaughlin Mike J. 
Published: June 2010

ABSTRACTSix sewage sludges from five sewage treatment plants in Australia were incubated for up to 21 months. Carbon losses at the end of the 21‐mo incubation varied substantially. The remaining organic matter was isolated by treatment with hydrofluoric acid (HF) and characterized using a range of solid‐state 13C nuclear magnetic resonance (NMR) spectroscopic techniques. By every measure (signal distribution in cross polarization [CP] and Bloch decay [BD] spectra, carbon NMR observability determined by spin counting, and the appearance of proton spin relaxation editing subspectra), the chemical composition of the residual organic matter appeared to be little different from that of the original sludges, even for those sludges that experienced the greatest carbon losses. Importantly, these NMR properties distinguish sewage sludge organic matter from soil organic matter. Thus, it should be possible to follow the decomposition of sewage sludge organic matter applied to soils in the field using solid‐state 13C NMR spectroscopy.
Near‐ and Mid‐Infrared Diffuse Reflectance Spectroscopy for Measuring Soil Metal Content
Authors: Siebielec Grzegorz , McCarty Gregory W. , Stuczynski Tomasz I. , Reeves James B. 
Published: June 2010

ABSTRACTRapid and nondestructive methods such as diffuse reflectance infrared spectroscopy provide potentially useful alternatives to time‐consuming chemical methods of soil metal analysis. To assess the utility of near‐infrared reflectance spectroscopy (NIRS) and diffuse mid‐infrared reflectance spectroscopy (DRIFTS) for soil metal determination, 70 soil samples from the metal mining region of Tarnowskie Gory (Upper Silesia, Poland) were analyzed by both chemical and spectroscopic methods. Soils represented a wide range of pH (4.0–8.0), total carbon (5.1–73.2 g kg−1), and textural classes (from sand to silty clay loam). Soils had various contents of metals (14–4500 mg kg−1 for Zn, 18–6530 mg kg−1 for Pb, and 0.17–34 mg kg−1 for Cd), ranging from natural background levels to high contents indicative of industrial contamination in the region. Soil samples were scanned at the wavelengths from 400 to 2498 nm (near‐infrared region) and from 2500 to 25000 nm (mid‐infrared region). Calibrations were developed using the one‐out validation procedure under partial least squares (PLS) regression. Mid‐infrared spectroscopy markedly outperformed NIRS. Iron, Cd, Cu, Ni, and Zn were successfully predicted using DRIFTS. The coefficients of determination (R2) between actual and predicted contents were 0.97, 0.94, 0.80, 0.99, and 0.96 for those metals, respectively. Only Pb content was predicted poorly. Calibrations using NIRS were less accurate. Root mean squared deviation (RMSD) values were from 1.27 (Pb) to 3.3 (Ni) times higher for NIRS than for DRIFTS. Results indicate that DRIFTS may be useful for accurate predictions of metals if samples originate from one region.
Particulate Phosphorus Transport within Stream Flow of an Agricultural Catchment
Authors: McDowell R. W. , Wilcock R. J. 
Published: June 2010

ABSTRACTThere is interest in quantifying phosphorus (P) loss from intensively grazed dairy landscapes to identify key pathways and target remediation methods. The Bog Burn drains a dairying catchment in Southland, New Zealand, and has been monitored at fortnightly intervals over a 12‐mo period at four sites for suspended sediment (SS), dissolved reactive phosphorus (DRP), and total phosphorus (TP). Time‐integrated samplers, deployed at 0.6 median water depth at each site (calculated from previous year's flow data), collected sediment samples, which were analyzed for SS, bioavailable phosphorus (BAP), and TP. Mean concentrations of DRP and TP in stream flow and BAP and TP in sediment were generally highest in summer or autumn (0.043 mg DRP L−1, 0.160 mg TP L−1, 173 mg BAP kg−1, 2228 mg TP kg−1) and lowest in winter or spring (0.012 mg DRP L−1, 0.034 mg TP L−1, 6 mg BAP kg−1, 711 mg TP kg−1), while loads were highest in winter. Analysis of 137Cs concentrations in trapped sediment, topsoil, subsoil, and stream bed and bank sediment indicated that trapped sediment was derived from topsoil and entered the stream either through tile drainage or, to a lesser extent, overland flow. Because concentrations of DRP and TP in stream flow are in excess of recommended limits for good water quality (>0.01 mg DRP L−1, 0.033 mg TP L−1), management should focus on the topsoil and specifically on decreasing P loss via tile drainage. This is best achieved by decreasing soil Olsen P concentrations, especially because, on average, Olsen P concentrations in the catchment were above the agronomic optimum.
Refined Tunable Methodology for Characterization of Contaminant–Particle Relationships in Surface Water
Authors: Marvin Christopher H. , Leppard Gary G. , West M. Marcia , Stern Gary A. , Boden Adrienne R. , McCarry Brian E. 
Published: June 2010

ABSTRACTTo understand contaminant transport in aquatic systems, it is essential to define the physical characteristics of the primary particulate carriers. The distribution of organic pollutants with particle‐size class and particle morphology in a freshwater embayment (Hamilton Harbor, western Lake Ontario) was studied using a sequence of novel sample preparation and characterization techniques. Water samples (24 L) were fractionated according to particle‐size distribution using differential cascade sedimentation and centrifugation methods. These size fractions were subsequently subjected to a physicochemical characterization using scanning transmission electron microscopy and energy‐dispersive spectroscopy to identify flocs and individual colloidal particles in the size range of 1 nm to 1 mm in diameter. Analytical chemical analyses were performed to identify organic contaminants in extracts prepared from particle‐size classes, including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). The contaminant distribution trends were very similar for all compound classes studied; contaminants were primarily associated with fractions containing particles less than 2 μm in diameter. Morphological characterization of these fractions showed the majority of the particulates to be humic fractals. The results of this study show that contaminants in aquatic systems can be preferentially associated with specific types of particle carriers, the characteristics of which can be clearly defined in terms of size and morphology.
Radionuclide Transport Above a Near‐Surface Water Table: IV. Soil Migration and Crop Uptake of Chlorine‐36 and Technetium‐99, 1990 to 1993
Authors: Shaw G. , Wadey P. , Bell J. N. B. 
Published: June 2010

ABSTRACTVertical distributions of 36Cl and 99Tc are presented from deep and shallow lysimeters above artificially controlled water tables for a 4‐yr experiment from 1990 to 1993. Activity concentration profiles were all measured in late summer when a winter wheat (Triticum aestivum L. cv. Pastiche) crop was harvested. After harvest, activity concentrations in different organs of the crop were determined and crop uptake quantified as both an inventory ratio (IR) and a transfer factor (TFw), weighted to account for differential root and radionuclide distributions within the soil profile. Vertical distributions of radionuclides, crop roots within the soil, and IR and TFw values were each subjected to analysis of variance to estimate the individual and combined effects of soil depth and the year of the experiment on the results obtained. Chlorine‐36 and 99Tc exhibited highly significant variations in activity concentrations with soil depth and from year to year, indicating considerable physical mobility of both radionuclides. Soil‐to‐plant transfer was also high for both radionuclides compared with data obtained for gamma‐emitting radionuclides. The IR values indicated that up to 40% of 36Cl was incorporated in the crop's tissues at harvest, compared with a maximum of less than 1% for the less mobile gamma‐emitting radionuclides. On the basis of the TFw values determined, 36Cl uptake by winter wheat exceeded 99Tc uptake, indicating that 36Cl is highly bioavailable. Factors controlling the migration and bioavailability of both 36Cl and 99Tc in soils are discussed.
Kinetic Effect of Humic Acid on Alachlor Degradation by Anodic Fenton Treatment
Authors: Wang Qiquan , Lemley Ann T. 
Published: June 2010

ABSTRACTContamination of water often results from the heavy use of agricultural chemicals, and the disposal of aqueous pesticide waste is a concern. Anodic Fenton treatment (AFT) has been shown to be a successful remediation method for pesticides in solution, but the effect of soil on the degradation kinetics of pesticides using this method has not been determined. The purpose of this study was to study the effect of humic acid, as a soil surrogate, on the degradation kinetics of alachlor [2‐chloro‐N‐(2,6‐diethylphenyl‐N‐(methoxymethyl) acetamide], a heavily used herbicide that has been studied in pure aqueous solution by AFT. The AFT consists of a controlled constant delivery of Fenton reagents, using an electrochemical half‐cell to deliver ferrous iron. Alachlor was quickly degraded by AFT, and the kinetics were found to obey the previously developed AFT model well. Degradation of alachlor by AFT in humic acid slurry showed that when the amount of humic acid was increased, alachlor degradation was significantly slowed down and the degradation kinetics were shifted from the AFT model to a first‐order model. Further experimentation indicated that humic acid not only competes with alachlor for hydroxyl radicals, reducing the degradation rate of the target compound, but also buffers the slurry at near neutral pH, blocking regeneration of ferrous ion from ferric ion and subsequently shifting the kinetics to first order. Degradation of several other pesticides in humic acid slurry also followed first‐order kinetics. These results imply that higher concentrations of Fenton reagents will be required for soil remediation.