bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application Technique and Slurry Co‐Fermentation Effects on Ammonia, Nitrous Oxide, and Methane Emissions after Spreading
Authors: Wulf S. , Maeting M. , Clemens J. 
Published: June 2010

ABSTRACTAmmonia emissions after spreading animal manure contribute a major share to N losses from agriculture. There is an increasing interest in anaerobic co‐digestion of liquid manure with organic additives. This fermentation results in a change of physical and chemical parameters of the slurry. Among these are an increased pH and ammonium content, implying a higher risk of NH3 losses from fermentation products. To compare different application techniques and the effect of fermentation on NH3 volatilization, we used the standard comparison method and tested it for reliability. This method seems to be perfectly suited for experiments with a large number of treatments and replicates if prerequisites concerning the experimental layout are considered. We tested four different application techniques on arable and grassland sites. The more the substrate was incorporated into the soil or applied near the soil surface on the grassland site, the less NH3 was lost. Injection of the substrate reduced losses to less than 10% of applied NH+4 on both sites, whereas losses after splash plate application amounted to more than 30%. Trail shoe application on grassland performed as well as injection. Harrowing on arable land also reduced emissions efficiently, if harrowing occurred within the first 2 h after application. Emissions from trail hose–applied co‐fermentation product were not greater than from unfermented slurry. Better infiltration of the less viscous substrate seemed to have compensated for the increased loss potential.
Mapping the Probability of Exceeding Critical Thresholds for Cadmium Concentrations in Soils in the Netherlands
Authors: Brus D. J. , de Gruijter J. J. , Walvoort D. J. J. , de Vries F. , Bronswijk J. J. B. , Römkens P. F. A. M. , de Vries W. 
Published: June 2010

ABSTRACTThe probability of exceeding critical thresholds of Cd concentrations in the soil was mapped at a national scale. The critical thresholds in soil were based on food quality criteria for Cd in crops or in organs of cattle (Bos taurus), and were calculated by inverting a regression model for the Cd concentration in the crop, with the Cd concentration in soil, soil organic matter (SOM) content, clay content, and pH as predictors. The probability of exceeding the critical threshold for Cd in soil per node of a 500‐ × 500‐m grid was approximated by Monte Carlo simulation, using the estimated cumulative distribution functions (cdf) of SOM, clay, pH, and Cd as input. The cdfs were estimated by simple indicator kriging with local prior means. For SOM, clay, and pH, detailed maps of soil type and land use were used to define subregions with assumed constant local means of the indicators (a priori distributions). The cdfs were sampled by Latin hypercube sampling. We accounted for correlation between the actual and critical Cd concentrations in soil by drawing Cd values from cdfs conditional on SOM and clay. The estimated probability for grassland is negligible, even in areas with high Cd concentrations in soil, and for maize (Zea maysL.) land the probability is almost everywhere smaller than 5%. For arable soils, however, these probabilities commonly are larger than 5% when sugar beet (Beta vulgarisL.) or wheat (Triticum aestivumL.) is taken as a reference crop, and locally exceed 50%.
Soil and Tree‐Ring Chemistry Response to Liming in a Sugar Maple Stand
Authors: Houle Daniel , Duchesne Louis , Moore Jean‐David , Laflèche Marc Richer , Ouimet Rock 
Published: June 2010

ABSTRACTAn evaluation of the impact of dolomitic lime [CaMg(CO3)2] on soils (five years after treatment) and sapwood chemistry (after four growing seasons) was realized for a Ca‐deficient sugar maple stand at the lake Clair watershed. The effect on humus chemistry was significant: exchangeable Mg and Ca, effective acidity (EA), base saturation (BSe), pH, and effective cation exchange capacity (CECe) significantly increased, while exchangeable Fe significantly decreased. In the B horizon, liming increased exchangeable Ca, Mg, and Mn concentrations while decreasing other acid cations. No significant temporal trends in element concentrations in tree rings could be detected, although the lime treatment significantly changed the average xylem Mg and Mn concentrations as well as the average Mg/Mn and Ca/Mn ratios of the sapwood. The absence of temporal trends in rings from the last 20 yr implied a significant re‐equilibration of elements through the sapwood. Significant relationships were found between averaged xylem Ca/Mn and Mg/Mn ratios and exchangeable humus Ca, Mg, Mn, Al, Fe, and H+concentration, EA, CECe, and BSe, suggesting that the average xylem Ca/Mn and Mg/Mn ratios are strong indicators of the soil acid–base status.
Growth and Yield Responses of Snap Bean to Mixtures of Carbon Dioxide and Ozone
Authors: Heagle A. S. , Miller J. E. , Burkey K. O. , Eason G. , Pursley W. A. 
Published: June 2010

ABSTRACTElevated CO2 concentrations expected in the 21st century can stimulate plant growth and yield, whereas tropospheric O3 suppresses plant growth and yield in many areas of the world. Recent experiments showed that elevated CO2 often protects plants from O3 stress, but this has not been tested for many important crop species including snap bean (Phaseolus vulgaris L.). The objective of this study was to determine if elevated CO2 protects snap bean from O3 stress. An O3–tolerant cultivar (Tenderette) and an O3–sensitive selection (S156) were exposed from shortly after emergence to maturity to mixtures of CO2 and O3 in open‐top field chambers. The two CO2 treatments were ambient and ambient with CO2 added for 24 h d−1 resulting in seasonal 12 h d−1 (0800–2000 h EST) mean concentrations of 366 and 697 μL L−1, respectively. The two O3 treatments were charcoal‐filtered air and nonfiltered air with O3 added for 12 h d−1 to achieve seasonal 12 h d−1 (0800–2000 h EST) mean concentrations of 23 and 72 nL L−1, respectively. Elevated CO2 significantly stimulated growth and pod weight of Tenderette and S156, whereas elevated O3 significantly suppressed growth and pod weight of S156 but not of Tenderette. The suppressive effect of elevated O3 on pod dry weight of S156 was approximately 75% at ambient CO2 and approximately 60% at elevated CO2 (harvests combined). This amount of protection from O3 stress afforded by elevated CO2 was much less than reported for other crop species. Extreme sensitivity to O3 may be the reason elevated CO2 failed to significantly protect S156 from O3 stress.
Evaluation of the Macroalga, Muskgrass, for the Phytoremediation of Selenium‐Contaminated Agricultural Drainage Water by Microcosms
Authors: Lin Z.‐Q. , de Souza M. , Pickering I. J. , Terry N. 
Published: June 2010

ABSTRACTPrevious field studies suggested that the macroalga, muskgrass (Chara canescensDesv. & Lois), plays an important role in the removal of selenium (Se) from agricultural drainage water. This study evaluated the efficiency of Se removal from drainage water by muskgrass‐vegetated wetland microcosms, and determined the extent to which muskgrass removed Se through phytoextraction and biovolatilization. Six flow‐through wetland microcosms were continuously supplied with drainage water containing an average Se concentration of 22 μg L−1over a 24‐d experimental period. The Se mass input and outflow and the rate of Se volatilization were monitored daily for each microcosm. Three microcosms containing muskgrass reduced the daily mass Se input in the inflow drainage water by 72.1%; this compared with a reduction of 50.6% of the mass Se input for three unvegetated control microcosms. Selenium accumulated in muskgrass tissues accounted for 1.9% of the total mass Se input in the microcosm, followed by 0.5% via biological volatilization. The low rates of Se volatilization from selenate‐supplied muskgrass, which were 10‐fold less than from selenite, were probably due to a major rate limitation in the reduction of selenate to organic forms of Se in muskgrass. This conclusion was derived from X‐ray absorption spectroscopy speciation analysis, which showed that muskgrass treated with selenite contained 91% of the total Se in organic forms (selenoethers and diselenides), compared with 47% in muskgrass treated with selenate.
Limnological Assessment of Verkhne Viiskii Reservoir, Russian Federation
Authors: Kennedy Robert H. , Hains John J. 
Published: June 2010

ABSTRACTVerkhne Viiskii Reservoir (surface area = 6.0 km2; volume = 36.0 hm3), one of two water supply reservoirs for the City of Nizhnii Tagil, is located in a forested watershed (drainage area = 272 km2) in the Ural Mountain region of the Russian Federation. This study, conducted in August 1999, provides a benchmark limnological assessment against which to gauge future change. While currently meeting local water quality requirements for drinking water sources, the reservoir exhibits moderately eutrophic characteristics, including elevated epilimnetic nutrient (total P = 0.048–0.115 mg L−1; total N = 0.421–0.508 mg L−1) and chlorophyll (4–8.4 μg L−1) concentrations, and a high rate of hypolimnetic oxygen depletion (4.07 g m−3 mo−1).
Responses of Red‐Osier Dogwood to Oil Sands Tailings Treated with Gypsum or Alum
Authors: Redfield E. , Croser C. , Zwiazek J. J. , MacKinnon M. D. , Qualizza C. 
Published: June 2010

ABSTRACTThe application of composite or consolidated tailings (CT) technology provides Alberta's oil sands industry with a means of reducing the volume of the fines fraction in extraction tailings and allows for faster reclamation and revegetation of mining sites. This study examined the effects of coagulant aids (gypsum and alum), used in the production of CT, on the ion content, growth, and survival of greenhouse‐grown red‐osier dogwood (Cornus sericea L. subsp. sericea). Seedlings were planted in gypsum‐CT and alum‐CT substrates, and compared with those planted in reclamation material (salvaged peat and till). The seedlings were bottom‐watered with one of the following: (i) Hoagland mineral solution prepared in deionized water (Epstein, 1972); (ii) Hoagland solution in gypsum‐based CT release water; or (iii) Hoagland solution in alum‐based CT release water. Pore water of CT substrates and CT release waters had similar chemical characteristics, including salinity levels. However, plants in CT substrates had higher concentrations of ions (particularly Na and B), reduced growth, and higher mortality than plants in reclamation material and treated with CT waters. The presence of H2S indicated low‐oxygen conditions in the CT substrates, while in the reclamation materials with CT release water treatments, no evidence of sulfides was observed. Low‐oxygen conditions in the CT substrate treatments may have interfered with plant exclusion mechanisms for Na and B. Therefore, substrate properties may modify responses of reclamation plants to pore water chemistry due to the effects on oxygen availability to roots.
Sequestration of Phosphorus by Acid Mine Drainage Floc
Authors: Adler Paul R. , Sibrell Philip L. 
Published: June 2010

ABSTRACTSolubilization and transport of phosphorus (P) to the water environment is a critical environmental issue. Flocs resulting from neutralizing acid mine drainage (AMD) were tested as a possible low‐cost amendment to reduce the loss of soluble P from agricultural fields and animal wastewater. Flocs were prepared by neutralizing natural and synthetic solutions of AMD with limestone, lime, ammonium hydroxide, and sodium hydroxide. Phosphorus sequestration was tested in three distinct environments: water, soil, and manure storage basins. In water, flocs prepared from AMD adsorbed 10 to 20 g P kg−1 dry floc in equilibrium with 1 mg L−1 soluble P. Similar results were observed for both Fe‐based and Al‐based synthetic flocs. A local soil sample adsorbed about 0.1 g P kg−1, about two orders of magnitude less. The AMD‐derived flocs were mixed with a high‐P soil at 5 to 80 g floc kg−1 soil, followed by water and acid (Mehlich‐1) extractions. All flocs performed similarly. About 70% of the water‐extractable P was sequestered by the floc when applied at a rate of 20 g floc kg−1 soil, whereas plant‐available P only decreased by about 30%. Under anaerobic conditions simulating manure storage basins, all AMD flocs reduced soluble P by greater than 95% at a rate of 0.2 g floc g−1 rainbow trout (Oncorhynchus mykiss) manure. These findings indicate that AMD flocs could be an effective agent for preventing soluble P losses from soil and manure to the water environment, while at the same time decreasing the costs associated with AMD treatment.
Atmospheric Ammonia, Volatile Fatty Acids, and Other Odorants near Beef Feedlots
Authors: McGinn S. M. , Janzen H. H. , Coates T. 
Published: June 2010

ABSTRACTIntensive livestock operations can release odorous gases from stored or land‐applied manure. We measured concentrations of dust and 14 odor‐causing gases at increasing distances from four feedlots near Lethbridge, southern Alberta, Canada. Concentration was determined from the amount of total dust or gas accumulated in the samplers, and the volume of air sampled. Adjacent the feedlots, the maximum concentration of many volatile fatty acids exceeded reported odor detection thresholds; the maximum ammonia concentration was close to the threshold. Ammonia and butyric acid approached or exceeded their individual odor thresholds as far as 200 m downwind of the feedlots. Highest concentrations were measured adjacent to land where manure was being applied. None of the odorant concentrations exceeded their irritation threshold. There was a positive relationship between ammonia concentration and odor intensity as well as dry deposition. Much of the emitted ammonia was deposited to soil immediately downwind, enough to supply all the nitrogen needed for crop growth. Odorant concentrations declined sharply with distance, though measurable odor occasionally persisted to 1 km from the feedlot, beyond the minimum separation guidelines (Alberta) for a single residential dwelling. The weekly averaged total suspended particulates (>5 μm) were below the Alberta guideline criterion except for one period. Differences among feedlots in odorant plume concentrations were partly related to the stocking density of feedlots, which presumably affects manure moisture and amount of volatiles within the pens.
Effect of Nonylphenol Surfactants on Fungi following the Application of Sewage Sludge on Agricultural Soils
Authors: Kollmann Albert , Brault Agathe , Touton Isabelle , Dubroca Jacqueline , Chaplain Véronique , Mougin Christian 
Published: June 2010

ABSTRACTThe effect of nonylphenol on fungi following the application of contaminated sewage sludge on agricultural soil was studied in laboratory experiments. Nonylphenol bioavailability and adsorption were determined in the soil alone and soil–sludge mixtures. Mixing the soil with sludge made it possible to measure the nonylphenol concentration in the soil solution, which comprised between 6.6 × 10−6 and 3.8 × 10−7 M, according to the sludge. We then examined the dose–response relationship between nonylphenol concentration in the culture medium and both biomass production and germination rate of the spores from several strains of filamentous fungi. When applied in this range of concentration, nonylphenol was without noticeable short‐term effect on these endpoints. Long‐term exposure of fungi to nonylphenol was also assessed. The most intensive effect was a strong stimulation of spore production and germination in Fusarium oxysporum Schlechtendahl. Biomass production by the Fusarium strains also increased. Finally, nonylphenol was shown to induce laccase production in Trametes versicolor We conclude that the potential of nonylphenol to adversely affect several soil fungi remains low.
Effects of Oxide Coating and Selected Cations on Nitrate Reduction by Iron Metal
Authors: Huang Yong H. , Zhang Tian C. , Shea Patrick J. , Comfort Steve D. 
Published: June 2010

ABSTRACTUnder anoxic conditions, zerovalent iron (Fe0) reduces nitrate to ammonium and magnetite (Fe3O4) is produced at near‐neutral pH. Nitrate removal was most rapid at low pH (2–4); however, the formation of a black oxide film at pH 5 to 8 temporarily halted or slowed the reaction unless the system was augmented with Fe2+, Cu2+, or Al3+ Bathing the corroding Fe0 in a Fe2+ solution greatly enhanced nitrate reduction at near‐neutral pH and coincided with the formation of a black precipitate. X‐ray diffractometry and scanning electron microscopy confirmed that both the black precipitate and black oxide coating on the iron surface were magnetite. In this system, ferrous iron was determined to be a partial contributor to nitrate removal, but nitrate reduction was not observed in the absence of Fe0 Nitrate removal was also enhanced by augmenting the Fe0–H2O system with Fe3+, Cu2+, or Al3+ but not Ca2+, Mg2+, or Zn2+ Our research indicates that a magnetite coating is not a hindrance to nitrate reduction by Fe0, provided sufficient aqueous Fe2+ is present in the system.
Bermudagrass Management in the Southern Piedmont USA
Authors: Franzluebbers Alan J. , Stuedemann John A. 
Published: June 2010

ABSTRACTFate of applied N in forage‐based agricultural systems is important to long‐term production and environmental impacts. We evaluated the factorial combination of N fertilization targeted to supply 20 g N m−2 yr−1 and harvest strategies on soil‐profile inorganic N during the first 5 yr of ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] management. Harvest strategy had much larger effects than fertilization strategy, most notably that soil‐profile inorganic N was lower when hayed than under other systems. In the upper rooting zone (0‐ to 0.3‐m depth), soil inorganic N (initially at 3.1 g m−2) remained unchanged during the 5 yr under unharvested and low and high grazing pressures (0.00 ± 0.08 g m−2 yr−1), but declined with haying (−0.25 g m−2 yr−1). In the lower rooting zone (0.3‐ to 0.9‐m depth), soil inorganic N (initially at 2.9 g m−2) accumulated with unharvested and low and high grazing pressure (0.64 ± 0.20 g m−2 yr−1), but remained unchanged with haying (−0.06 g m−2 yr−1). Below the rooting zone (0.9‐ to 1.5‐m depth), soil inorganic N (initially at 5.8 g m−2) increased with unharvested and high grazing pressure (0.34 ± 0.03 g m−2 yr−1), was unchanged with low grazing pressure (−0.10 g m−2 yr−1), and declined with haying (−0.50 g m−2 yr−1). Applied N appears to have been efficiently utilized by forage with subsequent sequestration into soil organic matter and little movement of inorganic N below the rooting zone (<2% of applied N), irrespective of inorganic or organic fertilization strategy designed to supply sufficient N for high animal production from grazing.
Aging Effects on the Sorption–Desorption Characteristics of Anthropogenic Organic Compounds in Soil
Authors: Sharer Michael , Park Jeong‐Hun , Voice Thomas C. , Boyd Stephen A. 
Published: June 2010

ABSTRACTField studies have demonstrated that prolonged pesticide–soil contact times (aging) may lead to unexpected persistence of these compounds in the environment. Although this phenomenon is well documented in the field, there have been very few controlled laboratory studies that have tested the effects of long‐term aging and the role of differing sorbates on contaminant sorption–desorption behavior and fate in soils. This study examines the sorption–desorption behavior of chlorobenzene, ethylene dibromide (1,2‐dibromomethane), atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine), and 2,4‐D (2,4‐dichlorophenoxyacetic acid) on one soil type after 1 d, 30 d, and 14 mo of aging. Sorption isotherms were evaluated after each aging period to observe changes in the uptake of each compound by soil. Desorption kinetic data were generated after each aging period to observe changes in release from soil, and desorption parameters were evaluated using a three‐site desorption model that includes equilibrium, nonequilibrium, and nondesorption sites. The data indicate no statistically significant increase in sorption for ethylene dibromide or chlorobenzene from 1 to 30 d, although sorption of 2,4‐D increased slightly, and sorption of atrazine decreased slightly. Statistically significant increases in linear sorption coefficients (Kd), from 1 d to 14 mo of aging, were apparent for ethylene dibromide and 2,4‐D. The Kd values for chlorobenzene, measured after 1 d, 30 d, and 14 mo of aging, were statistically indistinguishable. Aging affected the distribution of chemicals within sorption sites. With aging, the desorbable fraction decreased and the nondesorbable fraction, which was apparent after only 1 d of pesticide–soil contact, increased for all chemicals studied.
Using Nonequilibrium Thin‐Disc and Batch Equilibrium Techniques to Evaluate Herbicide Sorption
Authors: Smith M. Cade , Shaw David R. , Massey Joseph H. , Boyette Michele , Kingery William 
Published: June 2010

ABSTRACTNonequilibrium disc‐flow techniques may better reproduce dynamic soil–pesticide interactions than traditional batch sorption studies. Batch kinetic and equilibrium experiments and dual‐label thin‐disc flow experiments were conducted with atrazine (6‐chloro‐N‐ethyl‐N′‐isopropyl‐1,3,5‐triazine‐2,4‐diamine) and imazaquin [2‐(4,5‐dihydro‐4‐methyl‐4‐(1‐methylethyl)‐5‐oxo‐1H‐imidazol‐2‐yl)‐3‐quinolinecarboxylic acid] using a Demopolis silt loam (loamy‐skeletal, carbonatic, thermic, shallow Typic Udorthent; 8% clay, 62 g kg−1 organic matter, 7.6 pH). Batch kinetic studies with both herbicides revealed an almost instantaneous rapid phase and a much slower gradual phase. The rapid phase was complete after 5 min and equilibrium was reached at 24 h. The rapid phase accounted for 74% and 12 to 30% of the total amounts adsorbed for atrazine and imazaquin, respectively. The sorption of both the rapid and 24‐h isotherms for each herbicide best fit the Freundlich equation. The rapid and 24‐h Kf values of atrazine were 1.38 and 2.41, respectively, and the N value of both phases was approximately 0.93. For imazaquin, the rapid and 24‐h Kf values were 0.056 and 0.35, respectively, and the N value for the rapid phase of imazaquin was 0.71, compared with 0.86 for the 24‐h isotherm. In the dual‐label thin‐disc flow experiments, the average partition coefficient for atrazine at the peak soil concentration point was 1.54. This value closely agreed with the observed rapid‐phase Kf value of 1.38. In contrast, the thin‐disc flow experiments failed to detect any imazaquin retention. The thin‐disc flow method can allow for a greater resolution of rapid sorption kinetics, which is impractical with batch studies. Along with dynamic partitioning data, the thin‐disc flow method may provide kinetics data that may better complement environmental models than coefficients generated with batch techniques.