bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behavior of Chromium in Soils: VII. Adsorption and Reduction of Hexavalent Forms
Authors: James Bruce R. , Bartlett Richmond J. 
Published: July 2010

AbstractBased on adsorption studies with Fe(OH)3, Cr(OH)3, and soils, 10 mM K‐phosphate buffered at pH 7.2 was found to be adequate for characterizing exchangeable Cr(VI). The quantity of Cr(VI) removed from solution by 19 A and 19 B horizon soils from the northeastern United States was partitioned into two fractions, based on the amount of soil‐Cr extracted with the phosphate buffer. The fraction removed by the buffer was termed “exchangeable;” that retained by the soil was termed “nonexchangeable.” The nonexchangeable Cr(VI) not recovered by phosphate had been either reduced to an insoluble form of Cr(III), or had been precipitated or very tightly adsorbed by the soil as anionic Cr(VI).Of 20 µmol/100 g soil (23 kg/ha) Cr(VI) added, an average of 7.2 was removed by the unlimed 38 soils (mean pH 5.4). Of this quantity, 4.8 µmol were exchangeable by phosphate. Surface soils generally removed less Cr(VI) than B horizons (5.8 vs. 8.6 µmol/100 g), and the proportion of Cr(Vi) removed in phosphate‐exchangeable form also was lower. Liming to pH 7 decreased the average quantity of Cr(VI) removed by the soils to 2.6, with exchangeable and nonexchangeable forms each accounting for about 50% of the total.Sulfate and phosphate added with Cr(VI) to two A and two B horizon soils decreased Cr(VI) removal by the soil, with phosphate having a greater effect than sulfate. Although liming decreased Cr(VI) removal by the soils, even less Cr(VI) was held in exchangeable or nonexchangeable form in limed treatments containing the competing anions.Gallic acid rapidly reduced Cr(VI) held by soil colloids in exchangeable form except in limed samples of spodic horizons and a Hydric Dystrandept Ap, all high in amorphous, organically complexed Al and Fe sesquioxides.
Effect of Copper Levels in Swine Manure on Corn and Soil
Authors: Sutton A. L. , Nelson D. W. , Mayrose V. B. , Kelly D. T. 
Published: July 2010

AbstractEffects of Cu levels in liquid swine manure were studied for 5 y on corn (Zea mays L.) and Crosby silt loam soil (Aerie Ochraqualfs). Pigs housed on slatted floors above pits were fed 16% crude protein corn‐soy diets with either 0, 125, or 250 mg/kg of supplemental Cu as CuSO4. Swine manure (3.2–5.2% dry matter) collected from the anaerobic pits was surface‐applied annually to soil at rates of 90, 180, and 270 t/ha for 4 y. No manure was applied the fifth year to determine the effects of residual nutrients. Check and inorganic fertilizer (168 kg N/ha, 56 kg P/ha, 112 kg K/ha) treatments were also included.Supplemental CuSO4 in the swine diet increased Cu levels in manure and consequent Cu application to the soil. Copper‐enriched manure increased the 1N HCl‐extractable Cu in the upper portion of the soil profile (0–31 cm), but not at lower depths. High Cu applications from manure did not elevate plant leaf Cu concentrations, and did not adversely affect corn yields.Corn yields and leaf composition were not affected by rate of manure application since crop nutrient requirements were exceeded. Applied K and NO3−‐N moved downward in the soil profile, but a majority of these nutrients in soil were depleted by the end of the study. In contrast, applied P accumulated in the upper soil profile (0–31 cm).Application of liquid swine manure from pigs fed a high level of CuSO4 over a 4‐y period at the rates used in this study did not lead to excessive soil accumulation or enrichment of corn tissue with Cu.
Simultaneous Determination of Nitrate, Chloride, Sulfate, and Phosphate in Natural Waters by Ion Chromatography
Authors: Tabatabai M. A. , Dick W. A. 
Published: July 2010

AbstractSimultaneous analysis of anions in water samples is needed. Studies to evaluate the Dionex Model 10 Ion Chromatograph (IC) for simultaneous determination of NO3−, Cl−, SO42−, and PO43− in water samples, including soil extracts, showed that the results by the IC method agreed closely with those obtained by the steam‐distillation method for NO3−, colorimetric method using mercuric thiocyanate and ferric ammonium sulfate for Cl−, reduction and colorimetric determination as methylene blue for SO42−, and colorimetric molybdenum blue method for PO43−. The IC method is based on separation of the anions by a separator column containing Dionex low‐capacity anion‐exchange resin in the HCO3− form and on converting the various anions to their corresponding acids by a suppressor column containing a strong acid cation‐exchange resin in the H+ form. A solution 3.0 mM NaHCO3 + 2.4 nM Na2CO3 is used as the eluent, and electrical conductivity is used as the mode of detection. The method is precise and accurate, and can detect as little as 0.1 mg/L of NO3−‐N, Cl−, SO42−‐S, or PO43−‐P in water samples. The coefficient of variation ranged from 0.44 to 8.6% for NO3−‐N, from 0.14 to 4.3% for Cl−, from 0.13 to 1.1% for SO42−‐S, and from 0.55 to 8.6% for PO43−‐P. With the IC method, the 4 anions indicated can be determined simultaneously in 2 mL of water in approximately 10 min.
Laboratory Composter for Simulation Studies
Authors: Sikora L. J. , Ramirez M. A. , Troeschel T. A. 
Published: July 2010

AbstractA self‐heating laboratory composter comprised of a covered, double‐walled, insulated tank containing water, an air‐tight cylinder submerged in the tank, an inner screen mesh cylinder that held the organic material, a heater‐circulator, and a differential temperature control system was built and tested for use in studies simulating the biochemical changes that occur during composting. A mixture of raw, limed sewage sludge and woodchips was composted, and the weight‐loss data obtained were similar to that from the pilot plant composting facility at Beltsville, Md. The mixture lost 33% of its wet weight, and 9% of its dry weight during 28–50 d of composting. Six to ten percent of the total N was lost. There were two major temperature peaks, which correlated with CO2 increases. Peak NH3 evolution occurred when CO2 evolution decreased. All preliminary data indicate that the laboratory composter provides a comparable simulation of a large composting facility.
Microorganisms and Higher Plants for Waste Water Treatment
Authors: Wolverton B. C. , Mc Donald R. C. , Duffer W. R. 
Published: July 2010

AbstractBatch experiments were conducted to compare the waste water treatment efficiencies of plant‐free microbial filters with filters supporting the growth of reeds (Phragmites communis), cattail (Typha latifolia), rush (Juncus effusus), and bamboo (Bambusa multiplex). The experimental systems consisted of two components in series. The first component was an anaerobic settling‐digestion container. The second was a “nonaerated” trough filled with rocks, decreasing from large rocks (up to 7.5‐cm diam) at the bottom, to pea gravel (0.25‐ to 1.3‐cm diam) at the top. The plant‐free microbial filter was equally effective in carbonaceous BOD5 (5‐d biochemical O2 demand) removal. The vascular aquatic plant series enhanced ammonia removal, and consequently improved nitrogenous BOD5 removal. Under the conditions of these experiments, raw sewage with initial BOD5's of 100 mg/L can be upgraded to meet secondary standards with 6 h in component 1, and 6 h in a plant‐free filter or filter using cattail, rush, or reed. When initial BOD5's are approximately 450 mg/L, 24 h in component 1, 29 h in a reed filter are required to meet secondary standards. Total N removal studies were conducted, which demonstrated that a reed system is capable of removing NO3‐N and NH3‐N simultaneously, probably through a common NO2‐N intermediary, then to N2. Overall, the reed system was superior to all others evaluated in this research project.
Removal of Nitrogen and Phosphorus From Waste Water in a Waterhyacinth‐Based Treatment System
Authors: De Busk T. A. , Williams L. D. , Ryther J. H. 
Published: July 2010

AbstractThe importance of waterhyacinth plant material (living and detrital) as a sink for nitrogen (N) and phosphorus (P) was evaluated in a waste water treatment system in south Florida. The treatment system consisted of four ponds (0.1 ha each) from which plants were harvested, and one pond (0.2 ha) from which plants were not harvested. Nitrogen and phosphorus were removed in the plant standing crop at higher rates in the harvested ponds (362 and 115 mg m−2 d−1, respectively) than in the non‐harvested pond (55 and 15 mg m−2 d−1, respectively). However, immobilization of N and P as plant detritus in the sediment was less in the harvested ponds (3 and 1% of standing crop assimilation, respectively) than in the non‐harvested pond (33 and 13% of standing crop assimilation). With the exception of N in the nonharvested pond, estimates of nutrient removal by the waterhyacinth standing crop and detritus from 4 May–4 Aug. 1981 were similar (within 35 mg N or P m−2 d−1) to the observed nutrient removal from the waste water. Denitrification accounted for 92% of the N removed from the non‐harvested pond. On an areal basis, approximately 2.4 times more N was removed by denitrification in the non‐harvested pond than was assimilated by waterhyacinth growth in the harvested ponds (875 vs. 362 mg N m−2 d−1).Mean total N removal from the complete system resulted in an 87% reduction, from 9.96 to 1.25 mg/L. Total P was reduced only 10%, from 4.68 to 4.23 mg/L.
Impact of Ozone on Soybean Yield
Authors: Kress L. W. , Miller J. E. 
Published: July 2010

AbstractField‐grown soybeans [Glycine max (L.) Merr., cv. Corsoy] were exposed to O3 for 7 h daily (0900–1600 CST) for 56 d in open‐top chambers. The air in the chambers was either charcoal‐filtered or non‐filtered, with various constant amounts of O3 added. The randomized block design incorporated four replicates of six treatments: no chamber (0.042 ppm O3 seasonal 7‐h average); chamber with charcoal‐filtered air (0.022 ppm O3); and chambers with non‐filtered air plus added O3 to provide concentrations of 0.042, 0.064, 0.089, and 0.115 ppm. A linear reduction in seed weight per plant with increasing ozone dose (b (slope) = −87.18) was significant (P = 0.01), and yields were reduced 5, 23, 39, and 52% for the 0.042, 0.064, 0.089, and 0.115 ppm O3 treatments, respectively, compared with the 0.022 ppm treatment. Significant (P = 0.01) linear reductions were also noted for filled pods per plant (b = 184.4), seeds per filled pod (b = −0.9955), weight per seed (b = −0.3794), and percent oil content (b = −12.33). Significant (P = 0.01) linear increases were noted for unfilled pods per plant (b = 58.11) and percent protein content (b = 20.58). A comparison of the open plots with the nonfiltered air chamber plots provided with the same concentration of O3 revealed no significant chamber effects.
Fractionation of Phosphorus in Sludge‐Affected Soils
Authors: Chang A. C. , Page A. L. , Sutherland F. H. , Grgurevic E. 
Published: July 2010

AbstractPhosphorus accumulated in sludge‐treated soils was chemically fractionated by a sequential extraction procedure. Samples used for the study were obtained from experimental plots of a sludge land application site, where composted sludges at rates 0, 22.5, 45, and 90 t ha−1 y−1, and liquid sludges at rates of 0, 3.75, 7.5, and 15 cm/y have been applied for 5 y. There were also experimental plots whose liquid sludge treatments were terminated after 3 y. The experimental field was cropped with winter barley (Hordeum vulgare) after the sludge applications.In soils not treated with sludges, the Ca‐bound P accounted for 50–60% of the total P. An accumulation of Al‐ and Fe‐bound P occurred in all sludge‐treated soils. In the top 15 cm of surface soil, after 5 y of composted sludge treatment at a rate of 90 t ha−1 y−1 (1980), the Al‐ and Fe‐bound P was > 60% of the total P. Concentrations of water‐soluble P in sludge‐treated soils also increased. There were indications that the organically bound P in sludge‐treated soils was the most likely form to leach. Three years after the termination of sludge applications, there was little change in the distribution pattern of sludge‐borne P in the soil profile.
Assessing the Suitability of Soils With Macropores for Subsurface Liquid Waste Disposal
Authors: Bouma J. , Belmans C. , Dekker L. W. , Jeurissen W. J. M. 
Published: July 2010

AbstractThe capacity of soils to accept and purify liquid waste can be manipulated by using different application regimes. The associated transient soil physical conditions, which govern purification processes, were measured experimentally in soil columns and in situ, and were predicted by simulation in three soils of which two had macropores.Measurements of pressure heads, outflow rates, and breakthrough curves were made following intermittent liquid applications of 2 cm d−1. Rapid breakthrough and short‐circuiting, which were observed in the soils with the macropores, could be reduced by adding a light crust.Predictions involved computer simulation of pressure heads during infiltration and redistribution, and of outflow rates in the columns. Good agreement was found between measured and calculated values, but only when the model for soils with macropores was modified to include a subprogram for macropore flow. Simulation required hydraulic conductivity (K) at and near saturation, which was obtained with a modified crust test procedure.Use of the simulation program allows the prediction of soil physical conditions for a range of application rates in terms of ponding times and drainage rates, which affect purification and clogging. Measurement of breakthrough curves yields travel times as a function of application rates. Optimal application rates can be estimated by considering these two types of data, as is illustrated with an example. This approach is preferred over the current procedure using a single hydraulic parameter.
Application Mode and Alternate Cropping Effects on Atrazine Losses From a Hillside
Authors: Hall J. K. , Hartwig N. L. , Hoffman L. D. 
Published: July 2010

AbstractExternal drainage losses of atrazine (2‐chloro‐4‐[ethylamino]‐6‐[iso‐propylamino]‐s‐triazine) were evaluated at two application rates, applied preemergent, and pre‐plant‐incorporated on a hillside where corn (Zea mays L.) was planted with and without oats (Avena sativa L.) as a strip crop at the slope base. The cropping pattern had the most striking influence on soil, water, and atrazine transport in a growing season where a 100‐y frequency storm occurred during June. Statistical covariance analysis revealed that nearly 100% of the time, total atrazine residue losses in external drainage and soil sediment were most strongly related to the number of days from herbicide application to each erosion event.The small grain strip or buffer zone reduced water and soil losses by 66 and 76%, respectively, compared with nonstripped areas, during 11 erosion events. Atrazine losses of 3.5 and 0.33% of that applied (2.2 kg/ha) were recorded in the absence and presence of an oat strip, which represented a 91% reduction in herbicide loss with strip cropping. At the 4.5 kg/ha application rate, herbicide losses were reduced by 65% in the stripped areas compared with the nonstripped areas. Minimal pre‐plant incorporation of atrazine residues with the soil surface also significantly reduced residue loss with each cropping pattern. Using nonstripped, preemergent treated areas as a reference, pre‐plant incorporation of atrazine with strip cropping reduced total atrazine losses by 91 and 87% at the two respective application rates, and allowed only 7 g/ha of atrazine loss at each rate. Therefore, a conventional tillage‐management system combining a minimal surface‐blending of atrazine residues with strip cropping provided soil, water, and chemical residue retention equivalent to that achieved in reduced‐tillage crop management and controlled weeds effectively.
Stream Water Quality of Two Small Watersheds as Affected by Surface Coal Mining
Authors: Dick W. A. , Bonta J. V. , Haghiri F. , Page J. R. 
Published: July 2010

AbstractTwo small watersheds in eastcentral Ohio were selected for investigation of stream water quality prior to, during, and after surface coal mining and reclamation. Watershed C06 contained sandstone and shale overburden, and Watershed M09 contained limestone, sandstone, and shale. Water quality was monitored by measuring 39 parameters in the stream‐water samples collected. Duration curves for the four parameters regulated by the Office of Surface Mining (OSM) showed that most samples collected from the two study watersheds exceeded the 70 mg L−1 regulation level for suspended solids concentration. Approximately 50 and 30% of the water samples collected at Watershed C06 during the mining and reclamation period and the post‐reclamation period, respectively, exceeded the regulation level (4000 µg L−1) for manganese (Mn). Twenty percent of the pH values at Watershed C06 during the mining and reclamation period were also below the lower regulation level (pH 6). Concentrations of the major cations and anions, suspended solids, and dissolved solids were correlated with flow rate (log values) during the premine and post‐reclamation periods. Samples collected at similar flow rates at Watershed M09 showed concentrations of parameters were either not significantly affected or decreased in the post‐reclamation samples, compared with the premine samples. A similar comparison for samples collected at the C06 watershed showed parameter concentrations were generally higher during the post‐reclamation period. Parameters which were not detected in any samples collected from the two watersheds were arsenic (As), chromium (Cr) VI, mercury (Hg), and sulfide (S2−), while cyanide (CN−) was not detected at M09. Parameters that were only rarely detected were antimony (Sb), cadmium (Cd), lead (Pb), zinc (Zn), silver (Ag), copper (Cu), phenols, and phosphorus (P).
Evaluation of Soil Tests as a Measure of Phosphorus and Potassium Availability in Illinois Coal Waste
Authors: Lewis B. G. , Mc Kiernan M. 
Published: July 2010

AbstractThe Mitscherlich‐Bray relationship was applied to soil test‐extractable P and K in coal waste, and yield of tall fescue (Festuca arundinacea Schreb.) grown in the waste at pH 6.5. The typical exponential function between yield and extractable P obtained with soil‐grown plants was not exhibited by the waste‐grown plants for dilute acid or acid ammonium fluoride extractants, partly because values > 15 mg/kg extractable P in the waste could not be obtained despite heavy P fertilization. Correlation coefficients (r2) for extractable P in the growth media vs. P concentrations in shoots were 0.45 for the waste, and 0.81 for Elliott silt loam. Results with extractable K and yield on the waste were inconclusive, due to the confounding effect of an apparent Ca interference with K uptake. It is concluded that results of “soil testing” for P and K in coal waste should be interpreted with caution; in some cases, the tests may be inappropriate as indices of available forms of these elements in the waste.
Suspended Solids and Phosphorus Loads from a Clay Soil: II. Watershed Study
Authors: Culley J. L. B. , Bolton E. F. 
Published: July 2010

AbstractClay soil are very important agriculturally in southwestern Ontario, and they constitute a large proportion of the Canadian Lake Erie drainage basin. Analysis of water quality and quality from a typical clay watershed indicated that estimates of suspended solids load varied substantially, depending on the calculation method; this was not the case for P. Effluent from subsurface drains was estimated to constitute about 60% of annual runoff from the watershed. About 32 and 18% of the suspended solids load was probably derived from bank erosion and subsurface drainage, respectively. Contribution of P from these sources was also substantial. Sediment delivery of eroded soil from cropland was estimated to be about 7% of the sheet and rill erosion rate.
Effects of Soil Water Content on Pendimethalin Dissipation
Authors: Barrett Michael R. , Lavy Terry L. 
Published: July 2010

AbstractLaboratory and field studies were conducted to evaluate pendimethalin [N‐(1‐ethylpropyl)‐3,4‐dimethyl‐2,6‐dinitroaniline] dissipation over time in a Crowley silt loam (Typic Albaqualfs). In the laboratory, dissipation rates approximately followed pseudo first‐order kinetics over a 56‐d period, except in air‐dried soil that had no significant loss of pendimethalin detected after 56 d. Half‐lives for 30 kPa, continuous flood, and alternately flooded and dried treatments averaged 59, 63, and 30 d, respectively, under laboratory conditions. Application rates of 0.5, 1.0, and 2.0 µg/g of soil did not have a significant influence on the half‐lives. The ratio of pendimethalin residues in laboratory systems detected by a root bioassay with grain sorghum [Sorghum bicolor (L.) Moench.] to those detected with gas‐liquid chromatography (GLC) declined by 17% from 0 to 56 d after treatment. Dissipation in the field in each of 2 y was studied with lowland rice (Oryza sativa L.) (flush irrigated then flooded 2–3 weeks after application), upland rice (flush irrigated throughout the season), and soybean [Glycine max (L.) Merr.] (furrow irrigated as needed) management systems. Soil water content had a strong influence on the amount of pendimethalin that dissipated, especially for about the first 2 weeks after herbicide application. Half‐lives in the field were much shorter during the initial 2 weeks than after 2 weeks, with >50% of the applied herbicide having disappeared in 1 week for all treatments except in soybeans the first year. Soil persistence of pendimethalin was greater under soybean culture (soil‐incorporated herbicide, low irrigation frequency) than under rice culture (surface‐applied herbicide, high irrigation frequency, and/or flooded conditions).
Surface Runoff Water Quality Comparisons Between Unimproved Pasture and Woodland
Authors: Owens L. B. , Edwards W. M. , Van Keuren R. W. 
Published: July 2010

AbstractThe influence of pasturing on surface runoff water quality was studied on a 26‐ha, unimproved pasture watershed in eastcentral Ohio. Data were collected for 2 y with no cattle in the pasture and for 3 y with summer grazing by a 17‐cow beef cattle herd. Because of springs and seep areas in the pasture, a small stream (accessible to the cattle) in the watershed flowed permanently. Samples of storm runoff were collected with a rotating vane sampler. The concentrations of most of the measured chemical parameters (NO3‐N, mineral N, organic N, total P, K, Ca, Mg, Na, S, Cl, HCO3, total organic C, salts) in the storm discharge water were low and changed very little as a result of grazing. The weighted annual NO3‐N concentrations for the ungrazed period and grazed period were 0.5 and 0.7 mg/L, respectively, and the highest event concentrations were 1.2 and 3.8 mg/L, respectively.A 17.7‐ha, wooded watershed that contained no pastured areas and received no agricultural chemical inputs, had concentrations of chemical parameters in surface discharge that were greater than or equal to those from the unimproved pasture during the grazing period.Nutrient transport during storm runoff from the unimproved pasture was greater during the 3‐y period with summer grazing than during the 2‐y, ungrazed period. This largely resulted from increased precipitation and subsequent increased surface runoff during the 3‐y period. The transport levels from the pasture during the 3‐y period were similar to or less than the transport levels from the wooded watershed during the same period. The increase in sediment transport from the pastured area was more than could be attributed solely to the increased surface runoff.