bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preferential Movement of Oxygen‐18‐Labeled Water and Nitrogen‐15‐Labeled Urea through Macropores in a Nicollet Soil
Authors: Priebe D. L. , Blackmer A. M. 
Published: July 2010

AbstractStudies were conducted to evaluate the possibility that preferential movement of water through soil macropores was an important factor in previously observed losses of surface‐applied urea and nitrate from Iowa soils. Granules of 15N‐labeled urea were applied to the surfaces of undisturbed soil columns at their water‐holding capacities, and then 18O‐labeled water was applied to simulate a 25‐mm rainfall event. Effluent from the bottoms of the columns was incrementally collected and analyzed. Soil from the columns was removed in layers 24 h after initiation of the rainfall, and each layer was analyzed to determine depths of movement of labeled water and N. Significant amounts of labeled water and urea were present in the first increment of effluent from some columns. Labeled water and urea moved much deeper and were more dispersed in all soil columns than would be expected in absence of preferential movement of water through macropores. The results suggest that preferential movement of water through macropores is more important as a factor affecting the movement and fate of nitrogen in Iowa soils than generally has been recognized. A better understanding of where and when this preferential movement occurs and how it influences leaching of N and other solutes in soils is needed to advance efforts to identify management practices that reduce losses of N and other chemicals from agricultural soils to the environment.
Picloram Movement in Soil Solution and Streamflow from a Coastal Plain Forest
Authors: Michael J. L. , Neary D. G. , Wells M. J. M. 
Published: July 2010

AbstractPicloram (4‐amino‐3,5,6‐trichloropicolinic acid) was aerially applied to a longleaf pine (Pinus palustris L.) site in the upper coastal plain of Alabama to control kudzu [Pueraria lobata (Willd.) Ohwi]. Pellets (10% a.i.) were spread at the rate of 56 kg ha−1 on loamy sand Typic Kanhapludult soils. Movement of this herbicide was monitored with mineral soil samples, tension‐cup lysimeters, flow‐proportional streamflow samplers, and discrete samplers. Picloram levels in the upper 15 cm of mineral soil peaked at 0.96 to 2.25 mg kg1 25 d after application, depending on slope position, and declined to 0.13 to 0.29 mg kg1 1 yr later. In soil solution, picloram was detected at a depth of 0.4 m between 26 and 273 d after application. Only 4 of 15 lysimeters consistently contained detectable residues. Maximum picloram levels in soil solution were 130, 450, and 191 mg m−3 for ridge, midslope, and toe‐slope positions, respectively. Downstream monitoring began 4 d after the herbicide application, and an initial concentration of 68 mg m−3 of picloram was detected. The maximum downstream concentration of 77 mg m3 occurred 18 d after the application, immediately after the second storm event. Downstream levels dropped to <10 mg m3 after 90 d and to <2 mg m−3 after 200 d. Following localized retreatment along the stream more than a year after the initial treatment, levels climbed again into the 20 to 30 mg m3 range. Most of the initial off‐site movement came from a perennial stream that had been inadvertently treated, but subsequently storm runoff was the largest contributor to stream contamination. Picloram residues in this stream were similar to those observed downstream, but they were higher (up to 241 mg m3 and dropped faster to below 2 mg m3 after D 150.
Productivity of Clay Tailings from Phosphate Mining: I. Biomass Crops
Authors: Mislevy P. , Blue W. G. , Roessler C. E. 
Published: July 2010

AbstractPhosphate mining in Florida yields waste products of phosphatic clay and quartz sand tailings, each making up about one‐third of the original matrix (PO4 ore, sand, and clay). Phosphatic clay ponds typically occupy about 50% of the mined sites and normally require 10 to 15 yr before 40 to 50% solids are obtained. These clays contain no phytotoxic materials and are high in most plant nutrients. When surface water has disappeared, these clays are classified as clayey Haplaquents. A split‐plot field experiment was conducted to study biomass yield, quality, plant nutrient concentrations, changes in soil nutrients, and 226Ra. Seven biomass crops—(i) elephantgrass (Pennisetum purpureum L. ‘PI 300086’), (ii) leucaena [Leucaena leucocephala (Lam.) De Wet], (iii) alemangrass [Echinochloa polystachya (H.B.K) Hitche], (iv) erianthus [Erianthus arundinaceum (Retz) Jesw ‘IK 76‐63’], (v) desmodium (Desmodium cinerascens A. Gray), (vi) sweet sorghum [Sorghum bicolor (L.) Moench ‘USDA M 8IE’], and (vii) forage sorghum] Sorghum bicolor (L.) Moench ‘Pioneer 931’]—were grown on the phosphatic clay with and without a 5‐cm surface layer of quartz sand tailings. Nitrogen was the only fertilizer element applied for grass species and no fertilizer was applied for legumes during the 4‐yr period. Dry biomass yield averaged over 4 yr for erianthus, leucaena, and elephantgrass averaged 139.6, 58.5, and 56.5 Mg ha−1 yr−1, respectively. Crude protein and digestibility were low in mature, whole‐plant samples except for leucaena (122.0 g kg−1). Generally, all whole plants contained adequate concentrations of nutrients averaging (g kg−1) P, 2.05; K, 11.5; Ca, 4.3; Mg, 2.77 and (mg kg−1) Cu, 4.0; Zn, 26; Fe, 68; and Mn, 35. Mehlich‐I‐extractable soil nutrient concentrations changed little over the 4‐yr period. Radium‐226 concentration in plant tissue (0.23 pCi g−1) was nearly six times higher than the concentration measured in plants from an unmined surface Spodosol (0.04 pCi g−1). Data indicate that these present‐day waste lands can be a valuable resource for biomass production.
Acid Rain and Seed Yield Reductions in Corn
Authors: Craker Lyle E. , Waldron Peter F. 
Published: July 2010

AbstractSeed yields were significantly reduced on corn (Zea mays L.) plants where the silks had been exposed to an episode of simulated acid rain at pH 3.6 as compared with yields on plants with silks exposed to simulated rain of pH 5.6. The reduction in yield appeared related to a decrease in pollen germination and tube elongation associated with acidic conditions and limited quantities of pollen available for pollination. Germination and tube elongation of pollen were inhibited when grown on an agar medium acidified to pH 4.6 with simulated rain. Germination of pollen grains was reduced as much as 75% on silks previously exposed to a simulated rain of pH 3.6 as compared with germination on silks exposed to simulated rain of pH 5.6. The results suggest that under environmental conditions that limit the quantity of pollen, acid rain could reduce crop yields in corn by inhibiting the reproductive process.
Fate and Transport of Biological and Inorganic Contaminants from On‐Site Disposal of Domestic Wastewater
Authors: Reneau R.B. , Hagedorn C. , Degen M.J. 
Published: July 2010

AbstractAn on‐site wastewater disposal system (OSWDS) is the primary method for domestic waste disposal in sparsely populated areas and in numerous suburban counties. The most common OSWDS is a septic tank with a subsurface soil absorption system that relies on gravity to move wastewater from the residence to the soil with minimal pretreatment of waste before application to the soil. Much of the renovation occurs as the wastewater percolates through the soil prior to reaching ground or surface waters. In 1980, 20.9 million residences (24.1% of the total in the USA) applied approximately 14 × 109 L of domestic wastewater to U.S. soils each day. These numbers emphasize the need for assessing the effect of OSWDS on the quality of the environment. This review addresses the potential impact of selected biological and chemical contaminants present in domestic wastewater on environmental quality. Inefficient use of a soil's renovative capacity (primarily because of poor effluent distribution) can result in extensive travel distances for biological or chemical contaminants as well as hydraulic failure of the OSWDS. The need for further investigation of the potential for water contamination from nitrogenous components and possible mechanisms to reduce the degradation potential of N is addressed. Most studies assume that the dynamics of viral translocation through soil resemble those of fecal bacteria. This assumption may not be correct. Lastly, a critical examination of fate of N, viruses, and fecal bacteria introduced into soils via alternative OSWDS and modified conventional OSWDS should be a priority research initiative.
Application of Sewage Sludge and Other Amendments to Coal Refuse Material: II. Effects on Revegetation
Authors: Pietz R. I. , Carlson C. R. , Peterson J. R. , Zenz D. R. , Lue‐Hing C. 
Published: July 2010

AbstractThe effects of sewage sludge, lime, and gypsum on the revegetation of acidic coal refuse material were studied at a Fulton County, IL, land reclamation site. Treatments consisted of a control, 542 dry Mg ha−1 anaerobically digested sewage sludge, 89.6 Mg ha−1 lime, 112 Mg ha−1 gypsum, and combinations of these amendments. The experimental plots were seeded with a mixture of bromegrass (Bromus inermis Leyss.), tall fescue (Festuca arundinacea L.), and alfalfa (Medicago sativa L.). Yearly analysis of coal refuse material (0–15 cm) showed that the concentrations of NH+4‐N, [NO−3 + NO−2]‐N, available P, and water‐soluble K were the highest in sludge‐amended treatments, but they decreased with time. Plant yields increased each year from 1978 to 1980 in treatments receiving lime, sewage sludge, or both amendments. The highest yield of 6.00 Mg ha−1 occurred in the 1980 sludge + lime treatment. In 1980, the order of dry matter plant yields by treatments was sewage sludge + lime > gypsum + sewage sludge + lime > lime > sewage sludge > gypsum + sewage sludge > gypsum + lime > gypsum = control. Coal refuse and tissue K levels indicated that supplemental K would be desirable for long‐term maintenance of a vegetative cover. The better survival of bromegrass and tall fescue, as compared to alfalfa, reflected the coal refuse pH and the shorter root system of the more acid‐tolerant grasses. Concentrations of Al, Fe, Pb, and Zn in composite plant samples from some treatments exceeded the phytotoxic limits for these metals in plants. Potential plant toxicity from metals in the coal refuse material was most likely reduced by reactions with the applied sewage sludge and lime.
First‐Year Nutrient Availability from Injected Dairy Manure
Authors: Motavalli P. P. , Kelling K. A. , Converse J. C. 
Published: July 2010

AbstractEstimates of N, P, and K availability to corn (Zea mays L.) from injected dairy manure on three field sites in south central Wisconsin were made using a fertilizer equivalence approach. Nutrient uptake from treatments of a control, three rates of manure (approx. 53, 97, and 138 Mg ha−1 yr−1 on a wet basis), and three rates of broadcast fertilizer were evaluated. Crop nutrient recoveries of fertilizer N, P, and K were generally higher than crop recoveries of manure total N, P, and K. Estimates of first year N, P, and K availability showed substantial variability across rate, location, and year with standard deviations often about 50% of the mean. Ranges for N, P, or K availability were 12 to 63, 12 to 89, and 24 to 153%, respectively. These data do not identify those factors responsible for differences in nutrient availability from one site‐year to another. Biological or chemical availability indices of a 1‐wk anaerobic incubation at 40 °C or a 16‐h autoclaving in 0.01 M CaCl2 solution were evaluated as measures of N availability and compared with field results. Correlations between measured changes in NH4‐N from these indices, as well as total Kjeldahl N and inorganic N levels in the top 30 cm of soil 4 to 6 wk after treatment application, and N uptake indicated inorganic N levels to be a better index of N availability than the other indices examined. However, to determine nutrient availability on a routine basis, more reliable biological or chemical indices are necessary. A simple model may help to simulate environmental effects and the contribution of residual nutrients in the soil.
Chemical Properties of Metal‐Humic Acid Fractions of a Sewage Sludge‐Amended Aridisol
Authors: Senesi Nicola , Sposito Garrison , Holtzclaw Kenneth M. , Bradford Gordon R. 
Published: July 2010

AbstractHumic acid (HA) was extracted from a Domino soil (Xerollic Calciorthids) cropped with barley (Hordeum vulgare L.) and sorghum [Sorghum bicolor (L.) Moench] in experimental plots that received applications of sewage sludge for 4, 5, 6, or 7 yr at rates of 0,22.5, 45, or 90 Mg ha−1 yr−1. The HA samples were characterized chemically by elemental and functional group analyses, total trace metal content, infrared (IR), and electron spin resonance (ESR) spectroscopy. As compared to the nonamended Domino (Xerollic Paleorthids) soil HA, the highest sludge‐amended soil HA was extracted in higher yields and had higher N and S contents, lower C/N molar ratios, higher total acidity and phenolic OH content, lower organic free radical content, and higher relative intensity of the amide I and amide II IR absorption bands. These differences are believed to be caused by the incorporation of components typical of the applied sludge organic fraction into the soil HA, i.e., proteinaceous materials, sulfur‐containing compounds, and phenolic components. The HA also exhibited a well‐defined selectivity in respect to trace metal adsorption/desorption. Copper, Ni, Zn, Fe, and Cr were adsorbed strongly onto readily available sites, or through exchange with more weakly adsorbed trace metal ions (Mn, V, Ti, and Mo). However, the soil HA tended to reach metal saturation at the highest sludge application rates. The ESR analysis showed the presence of indigenous Cu2+, Fe3+, and VO2+‐HA complexes in all HA samples. These complexes had similar chemical and structural properties, and were concluded to represent the speciation of the metals in association with HA. In general, the impact of the organic constituents in fresh sludge on the soil HA appeared to be mitigated somewhat by the continual tendency of soil organic matter to attain equilibrium, whereas the metal‐organic portion of the soil HA was significantly affected by sludge application.
Environmental Fate of Picloram Used for Roadside Weed Control
Authors: Watson V. J. , Rice P. M. , Monnig E. C. 
Published: July 2010

AbstractThe herbicide picloram (4‐amino‐3,5,6‐ trichloro‐2‐pyridine carboxylic acid) was applied to control spotted knapweed (Centaurea maculosa Lam.) in the northern Rockies to determine persistence in soils and vegetation, losses by photodegradation, rainfall induced migration, and potential contamination of surface and groundwater. Two sites were selected to represent best case and worst case conditions (within label restrictions) for on‐site retention of picloram. A valley bottom terrace was treated with 0.28 kg/ha of picloram in the spring of 1985, and sampled over the following 445 d. In the spring of 1986, 1.12 kg/ha of picloram was applied to both sides of a minimal construction logging road extending 4 km along a stream (102 to 815 m3) that drains agranitic upper mountain watershed. Of the 17.1 km2 watershed, 0.15% (2.5 ha) was sprayed. Vegetation, soils, surface water, and groundwater near the road were sampled during the 90 d following application. At the valley bottom site, 36, 13, and 10.5% of the picloram applied persisted after 90, 365, and 445 d, respectively. At the mountain watershed site, 78% persisted after 90 d, and picloram was not detected in the surface or groundwaters during the 90 d following application. Depending on the timing of delivery, as little as 1% or less of the application could have been detected after delivery to the stream. Loss by photodegradation during the first 7 d after treatment was important at both sites.
Effects of Cations on Complexation of Naphthalene by Water‐Soluble Organic Carbon
Authors: Traina Samuel J. , Spontak Donna A. , Logan Terry J. 
Published: July 2010

AbstractThe effects of cation type (Na, Ca, or Al), pH, and stoichiometric ionic strength (Is) on the complexation of naphthalene (in ClO−4 media) by water‐soluble soil organic matter extracted from a muck soil (Euic, mesic Typic Medisaprist) were investigated with a fluorescence quenching technique. Decreases in the intrinsic fluorescence of the naphthalene, resulting from additions of water soluble soil organic matter (0–28 mg L−1 C expressed as water‐soluble organic carbon or WSOC) were used to calculate conditional naphthalene‐WSOC stability constants (cKoc) for each of the electrolyte systems investigated. For all cases, increased aqueous concentrations of WSOC caused an increase in the formation of naphthalene‐WSOC complexes. Changes in pH value from 1.5 to 7.3 (in the presence of 0.05 mol L−1 NaClO4) and changes in Is from 0.05 to 0.5 mol L−1 [in the presence of either Ca(ClO4)2 or Al(ClO4)3] had no effect on the binding of naphthalene by WSOC. In homoionic systems of either NaClO4, Ca(ClO4)2, or Al(ClO4)3) (for Is = 0.05 mol L−1), the formation of naphthalene‐WSOC complexes decreased in the order Na = Ca > Al. The effect of Al on the binding of naphthalene by WSOC may have resulted from changes in the physical, polymeric structure of WSOC molecules caused by the presence of Al as a counter ion.
Sediment and Nutrient Losses from an Unimproved, All‐Year Grazed Watershed
Authors: Owens L. B. , Edwards W. M. , Van Keuren R. W. 
Published: July 2010

AbstractA common practice for grazing land in the humid, eastern USA is continuous grazing with little or no fertilizer use. Concentrations and transport of nutrients from a 28‐ha unimproved grassed watershed were assessed in east‐central Ohio for 2 yr without the presence of livestock, for 3 yr with a 17‐cow beef (Bos taurus) herd grazing during the summer months only, and for an additional 6‐yr period with all‐year grazing with hay being brought in for winter feed. Nutrient concentrations remained low during all three grazing levels. An exception was K concentration, which increased with all‐year grazing. Concentrations of NO3‐N, mineral‐N, P, Ca, Mg, Na, and Cl were similar to or less than the concentrations from a nearby 17.7‐ha wooded watershed that contained no pastured areas and received no agricultural inputs. Nutrient concentrations showed no consistent seasonal variation. Concentrations of organic‐N, total organic C and sediment increased with increased grazing pressure. Greatest sediment concentrations and transport rates generally occurred during July and August regardless of grazing system. Largest monthly average sediment concentrations were 0.8, 1.3, and 3.2 g/L for the three systems, respectively; annual sediment losses were 0.2, 1.2, and 2.1 Mg/ha, respectively. All‐year cattle grazing/feeding on an unimproved pasture in this area would not be expected to produce degradation of stream water quality from nutrient concentrations or transport.
Effects of Air Filtration on Concentration and Deposition of Gaseous and Particulate Air Pollutants in Open‐Top Field Chambers
Authors: Bytnerowicz A. , Olszyk D. M. , Dawson P. J. , Morrison L. 
Published: July 2010

AbstractConcentrations of gaseous and particulate air pollutants, and deposition fluxes of NO−3, SO2−4, and NH+4 ions to branches of California lilac (Ceanothus crassifolius Torr.), Coulter pine (Pinus coulteri D. Don.), ponderosa pine (P. ponderosa Dongl. ex P. & C. Lawson), nylon filters, and paper filters were measured in open‐top field chambers with different filtration materials and in chamberless outside plots. Concentrations of O3 inside charcoal‐filtered (CHARCOAL) chambers were reduced to 18 to 24% of the outside concentrations, while concentrations of NO2 were reduced to about 42 to 67%, with a simultaneous increase of NO concentrations. Concentrations of these gases in the chambers equipped only with the fiberglass dust filter (DUST 1) and fiberglass dust filter plus heavy duty strainer mat (DUST 2) were similar to those in the outside plots. On the average, concentrations of NO−3 (sum of particulate nitrate and nitric acid vapor) in the CHARCOAL chambers were reduced to about 40% of the outside levels, while concentrations of particulate SO2−4 and NH+4 (sum of particulate NH+4 and NH3) were reduced to about 84 and 79%, respectively. In the DUST 1 and DUST 2 chambers, concentrations of NO−3 were reduced to about 73% of the outside levels, and concentrations of SO2−4 and NH+4 to about 90 and 92%, respectively. Effects of different air filtrations were more evident for deposition fluxes to plant and surrogate surfaces. On the average, in the CHARCOAL chambers, deposition fluxes of NO−3, SO2−4, and NH+4 to the surfaces were reduced to 21, 38, and 26% of the outside values, respectively. In the DUST 1 and DUST 2 chambers, deposition fluxes of NO−3, SO2−4, and NH+4 were reduced to about 50, 56, and 75% of the outside levels, respectively. Deposition fluxes of the studied ions to plants were much lower than to nylon and paper filters. The results of this study add important information for open‐top chamber studies, especially if long‐term effects of ambient concentrations of air pollutants on vegetation are considered.
Transformation and Mineralization of Metribuzin in Surface and Subsurface Horizons of a Mississippi Delta Soil
Authors: Moorman T. B. , Harper S. S. 
Published: July 2010

AbstractThe rates of degradation and mineralization of metribuzin [4‐amino‐6‐(1,1‐dimethylethyl)‐3‐(methylthio)‐1,2,4‐triazin‐5(4H)‐one] were determined in the surface and subsurface horizons of a Dundee silty clay loam soil (Aeric Ochraqualf) from the Mississippi Delta. Residual metribuzin and metabolites were measured by HPLC or TLC methods during or after 91‐d incubations of treated soil in the laboratory. Metribuzin degradation was faster in the surface soil than in the subsurface soils. Degradation in the surface and the subsurface horizons were not described by first‐order kinetics. Degradation was a second‐order process in the surface soil, but only a half‐order process in the subsurface horizons. Considerably more mineralization of 14C‐metribuzin occurred in the surface (0‐ to 10‐cm depth) soil, with 15 to 20% evolved as 14CO2 after 91 d, vs. 5% from the subsurface soils. Substantial amounts of 14C‐bound residues were formed in both surface and subsurface horizons. Reduced microbial populations and activity corresponded to the reduced degradation of metribuzin in the subsoils.
A Comparison of Sorption Equilibrium Distribution Coefficients Using Batch and Centrifugation Methods
Authors: Celorie J. A. , Woods S. L. , Vinson T. S. , Istok J. D. 
Published: July 2010

AbstractSorption equilibrium distribution coefficients, Kd's, are often used in solute transport models to predict the movement of hazardous wastes in soils. Kd values can be determined in the laboratory by performing batch equilibrium tests or column studies. However, these tests suffer from disadvantages. Batch tests may overestimate sorption in natural soils due to the solids effect, and column studies conducted with fine‐grained soils require a long time to conduct. Centrifugation testing can alleviate these disadvantages by testing a soil column instead of a soil suspension, by imposing a confining stress on the soil, and by producing a greater pore water velocity. Centrifuge experiments were conducted on a kaolinite/phenol system using a constant head permeameter and a laboratory centrifuge. Kd values were estimated by modeling the generated breakthrough curves with a solute transport model. Kd values obtained in the centrifuge experiments were compared with Kd values measured in batch equilibrium tests. Although the Kd values determined in the centrifuge were slightly lower than the values predicted by extrapolating the batch data, the results were consistent with the solids effect.