bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen Availability and Uptake from Field Soils Five Years after Addition of Sewage Sludge
Authors: Harding S. A. , Clapp C. E. , Larson W. E.
Published: July 2010

Nitrogen availability and uptake from sewage sludge were studied in a field experiment during 1979 on a Hubbard sandy loam soil (Entic Haploboroll). Treatments of anaerobically digested (low, 6370; medium, 12 770; and high, 25 200 kg N ha−1), aerobically digested (12 540 kg N ha−1) and waste‐activated (24 500 kg N ha−1) sludge were applied between 1972 and 1974. By 1975, 50% more total N remained in plots receiving anaerobic sludge than in plots receiving equivalent N rates of waste‐activated or aerobic sludge. By 1979, only 12% of the 1975 level of potentially mineralizable N (N0) remained in the waste‐activated sludge plots, followed by anaerobic sludge (3, 11, and 9% in the low, medium, and high levels, respectively) and aerobic sludge (2%). In 1979, N uptake by maize (Zea mays L.) ranged from 67 kg N ha−1 to 184 kg N ha−1 on sludge‐treated plots and was 158 kg N ha−1 on fertilized controls [250 kg N ha−1 as (NH4)2SO4; 0 sludge]. Due to early depletion of N0 in aerobic sludge and slow current rate of mineralization of N0 in waste‐activated sludge, N uptake in 1979 from those sludge treatments was 51 and 58%, respectively, as high as from equivalent N application rates of anaerobic sludge. Maize grain and fodder yields reflected the uptake differences. In the 0‐ to 15‐cm soil depth, mineral N at planting time ranged from 23 kg N ha−1 in aerobic and low anaerobic treatment plots to 31 kg N ha−1 in medium and high anaerobic treatment plots. Multiple regression analysis indicated the effect of residual mineral N at planting time was more important than N mineralized during the season for both amount and efficiency of N uptake. Low residual NO3−‐N in the 0‐ to 15‐cm depth limited maize uptake of N mineralized during the season and of previously mineralized N present below the 45‐cm depth. The relative influence of residual mineral N on N uptake changed after sludge application. Therefore, combined N indexes and decay series should be used when estimating long‐term N supplying power of high sludge applications.
Effects of Anaerobically Digested Poultry Manure on Soil Phosphorus Adsorption and Extractability
Authors: Field J. A. , Reneau R. B. , Kroontje W.
Published: July 2010

Research in the past has indicated that large additions of animal manures to soil can reduce soil P adsorption and increase P extractability. However, application rates used in many studies are unrealistic with respect to crop fertilization and land disposal due to the excessive quantities of N applied with the manures. The objective of this study was to evaluate effluent from a poultry manure anaerobic digester applied to a Hayesville loam soil (clayey, oxic, mesic, Typic Hapludult) on soil P adsorption and extractability after three incubation periods (0, 30, and 90 d). Effluent solids were applied at rates corresponding to 753 through 7530 mg N kg−1 soil.

Langmuir equation parameters (from least square fitted data; R2 > 0.98) were used as a basis to compare the influence of treatments on P adsorption properties of the soil. The P adsorption maxima parameter was not influenced by any of the effluent treatments. The parameter related to P bonding energy of the soil was reduced 33 and 41%, respectively, by mid and high rate effluent applications. A similar reduction was not observed for the low rate treatment, which corresponded to fertilizer application of 100 mg N kg−1 soil.

Extractable soil P increased in a predictable manner with increased effluent solids application for all three incubation periods. These increases in extractable P could be described by linear regression equations. The slopes of these lines indicate that a 1‐g addition of effluent solids to 1‐kg soil accounts for increases in extractable P of 3 to 6 mg kg−1.
Irrigation of Forages with Rendering Plant Wastewater: Forage Yield and Nitrogen Dynamics
Authors: Bole J. B. , Gould W. D.
Published: July 2010

Wastewater from an animal by‐product rendering plant containing N, P, and biochemical oxygen demand (BOD) at greater than 500, 60, and 500 mg L−1, respectively, was applied to irrigated forages to study the suitability of forage species and the fate of applied nutrients. Applications of 10 and 20 cm yr−1 supplied the nutrients at rates in excess of crop requirements. The treatments were compared with irrigation water and with water supplemented with either fertilizer N and P or C as sugar at rates similar to those in the wastewater. Reed canarygrass (Phalaris arundinacea L.) yields were doubled by the application of 10 cm yr−1 of wastewater as compared with irrigation water treatments, but alfalfa (Medicago sativa L.) yields were not significantly affected. Doubling the wastewater application rate or adding comparable rates of N and P fertilizer did not further increase yields. The wastewater‐irrigated alfalfa contained NO3−‐N levels of 1500 to 1600 mg kg−1 plant material, while reed canarygrass contained about 3000 to 3400. Both these levels would be considered potentially unsafe for livestock feed. There was an accumulation of soil NO3−‐N levels of up to 30 to 40 mg kg−1 soil throughout the surface 120 cm of soil after 5 yr of irrigation with 10 cm yr−1 of wastewater and two to three times this level with 20 cm yr−1 of wastewater. Higher levels of NO3−‐N were observed in the soil when N was applied as fertilizer. Soil NH4+‐N levels were not greatly affected. A nitrogen balance over 6 yr at the high application rate suggested plant uptake, soil NO3−‐N, and losses accounted for 30, 25, and 45% of wastewater N and 29, 39, and 32% of fertilizer N. A 1‐yr 15N balance after 3 yr of irrigation indicated uptake, soil NO3−‐N, and unaccounted‐for N was about 10, 19, and 71% for wastewater and 15, 33, and 52% for fertilizer N. The greater losses of wastewater N compared with fertilizer N were attributed to enhanced denitrification due to oxidizable C in the wastewater. Attempts to simulate this effect with C as sugar were not effective.
Adsorption and Desorption of Hexavalent Chromium in an Alluvial Aquifer Near Telluride, Colorado
Authors: Stollenwerk K. G. , Grove D. B.
Published: July 2010

A laboratory investigation of reactions between hexavalent chromium [Cr(VI)] and alluvium was conducted to evaluate reactions of Cr(VI) contaminating an alluvial aquifer near Telluride, CO and to determine the mechanisms responsible for these reactions. Uncontaminated alluvium and groundwater (spiked with CrO42−) from the study site were used in batch and column experiments. Results of these experiments show that Cr(VI) was adsorbed by the alluvium. Distribution coefficients from batch experiments ranged from 52 L/kg at an equilibrium CrO42− concentration of 0.4 µmol/L to 1.7 L/kg at an equilibrium concentration of 1400 µmol/L. The zero point of charge for the alluvium was approximately 8.3, and the alluvium had a positive net charge at the groundwater pH of 6.8. Visual and chemical evidence indicated that Fe oxide and hydroxide coatings on the alluvial particles principally were responsible for the adsorption of Cr(VI). During column experiments, Cr(VI) initially was desorbed easily from the alluvium by Cr‐free groundwater; however, the rate of desorption decreased rapidly, and > 60 pore volumes of groundwater were required to decrease the effluent concentration of Cr(VI) to 3 µmol/L [drinking water standard for Cr(VI) = 1 µmol/L]. The quantity of Cr(VI) adsorbed varied with the type and concentration of other anions in solution.
Effect of Sludge Application on Physical Properties of a Silty Clay Loam Soil
Authors: Wei Q. F. , Lowery B. , Peterson A. E.
Published: July 2010

This study was conducted to elucidate the long‐term effect of dewatered sludge application on a silty clay loam soil, which possesses poor permeability and other undesirable physical properties. A Zimpro®‐processed dewatered sludge was applied in early 1977 at treatment rates of 0, 11.2, 22.4, 44.8, and 112.0 Mg ha−1 (dry solids basis) to a Kewaunee silty clay loam soil (Typic Hapludalf). A sixth treatment was an annual application of 22.4 Mg ha−1 from 1977 to 1982, resulting in a total input of 134.4 Mg ha−1.

Bulk density, infiltration, hydraulic conductivity, and aggregate stability were measured $ yr after application (note: fifth year of annual sludge application at 22.4 Mg ha−1). The bulk density decreased by 0, 0.7, 3.5, 8.3, and 6.3% over the control for the 11.2, 22.4, 44.8, 112.0, and 134.4 Mg ha−1 of sludge treatment, respectively. The hydraulic conductivities of saturated soil cores were 0, 4.2, 45.4, 70.2, and 70.6% higher for the 11.2, 22.4, 44.8, 112.0, and 134.4 Mg ha−1 sludge treatment, respectively, over the control. The improved soil permeability was due to the enhancement of aggregate stability, which increased relative to the control by 3.3, 9.4, and 11.9% with the 44.8, 112.0, and 134.4 Mg ha−1 treatment, respectively. The in situ volumetric moisture content of the sludge‐treated soils was always higher than the control, especially after a prolonged period of evaporation. At 33.3 kPa or less, more water was released from soils treated with high rates of sludges. This indicated an increase in the volume of larger pores, which resulted in the higher hydraulic conductivities.

Lower rates of sludge treatments (11.2 and 22.4 Mg ha−1) had no effects on the soil physical properties after 5 yr. Small yearly applications improved the soil physical properties equally as well as a single large application.
Percolation Tests, Soil Texture, and Saturated Hydraulic Conductivity in Lacustrine Soils in North Dakota
Authors: Conta J. F. , Richardson J. L. , Prunty Lyle
Published: July 2010

Percolation tests were unreliable estimators of in situ saturated hydraulic conductivity (Ksat) if the data were to be used to predict soil permeability for on‐site septic disposal systems in soils with > 0.35 kg/kg clay (r = −0.38 [nonsignificant], p = 0.01). The wide variations in percolation rates (10.5–135.9 min/cm) measured on similar pedons with silty clay or clay textures were attributed to the pedal nature and vertic properties that exist in high clay content soils of the area. Percolation rates yielded good estimates of Ksat in soils with < 0.35 kg/kg clay (r = −0.79**, p = 0.01) (** indicates significance at the 1% level). The soil clay content and Ksat rate correlated with sufficient precision over a wide range of soil textures for clay content to be used in predicting permeability and to permit using permeability to interpret the soil suitability for septic absorption fields. This research showed that clay content could reliably form the basis of a sanitary code.

A comparison of in situ Ksat rates and estimated permeability ranges used by the Soil Conservation Service revealed that many fine‐textured soils have permeabilities greater than the Soil Conservation Service ranges indicate. The ranges of permeability should be expanded for these fine‐textured soils to include more rapid permeabilities.
Laboratory Investigation of Leachate Chemistry from Six Appalachian Forest Floor Types Subjected to Simulated Acid Rain
Authors: De Walle D. R. , Ribblett G. C. , Helvey J. D. , Kochenderfer J.
Published: July 2010

In order to determine the role of the forest floor in neutralization of strong acidity in acid rain, simulated acid rain at pH 4.0 was applied under laboratory conditions to forest floor samples from six Appalachian forest types. Effects of forest type, storm size, and repeated storm applications on leachate chemistry were investigated. Forest floor leachate from a hemlock forest [Tsuga canadensis (L.) Carr.] showed significantly lower pH (mean pH 3.9) than other leachate types due to high concentrations of organic acids. Cove hardwood forest found in an area with calcareous soil parent material produced forest floor leachate with a significantly higher pH (mean pH 6.5) than other forest types. Forest floor leachates from mixed oak (Quercus spp.), northern hardwood, red pine (Pinus resinosa Ait.), and white pine (P. strobus L.) forests were intermediate in pH (mean pH 4.1–4.4) due to the acidifying influence of organic acid leaching balanced against the neutralizing effect of H+ exchange for Ca2+ in the forest floor. Weak acidity concentrations obtained by Gran plots were well correlated with 400‐nm wavelength transmittance and anion deficits in the leachates. Organic anions dominated leachates from hemlock and mixed oak forest types. Increasing storm sizes caused reduced ionic concentrations, especially of H+, Mg2+, and Ca2+, but three repeated storms produced no consistent significant reductions in loads or concentrations.
Long‐Term Phosphorus Sorption in a Brunisol in Response to Dosed‐Effluent Loading
Authors: Nagpal N. K.
Published: July 2010

Phosphorus sorption characteristics of a major soil in the Shawnigan Lake area of Vancouver Island were studied in response to periodic secondary effluent loading. Five soil columns 0.60 m long and 0.139 m in diam were prepared from the B horizon of the Shawnigan gravelly silt loam (classified as a Dystric Brunisol and Typic Dystrochrept according to the Canadian and U.S. Systems of soil classification, respectively). Water table level was maintained at the base of the two partially saturated columns (PSC). The other three columns (USC) remained unsaturated at all times and were subjected to a tension of 6.0 kPa. A single, daily dose of 1 L (∼6.6 cm) of secondary effluent was applied to all columns except on weekends and holidays.

The effluent P was retained effectively by the USC columns initially, but broke through with time as in case of the PSC columns. The leachate P concentration reached an equilibrium value (EPC) after about 70 pore volumes of effluent had passed through the columns. The EPC changed only slightly beyond 70 pore volumes, but was a function of effluent P concentration and percolation rate. About 60 to 90% of added P was retained by the columns, even after 2.7 yr of leaching. Surface layers were the most effective renovators of effluent P; however, the total amount of P retained by the soil was dependent more on effluent percolation rate and leaching period, and less on water table level.
Enhanced Biodegradation of Polychlorinated Biphenyls in Soil by Analog Enrichment and Bacterial Inoculation
Authors: Brunner Walter , Sutherland Fain H. , Focht Dennis D.
Published: July 2010

Carbon‐14‐labeled polychlorinated biphenyls (PBC) representing the commercial Aroclor 1242 mixture (a mixture of chlorinated biphenyls) were incubated in soil over a 210‐d period to determine if biodegradation could be enhanced by additions of straw and sludge, aerobic and anaerobic incubations, or combinations thereof. Although PCB (100 mg/kg) had no effect on microbial respiratory processes in soil, mineralization did not exceed 3% of the total added. Also, neither 14CO2 nor 14CH4 was produced from anaerobic incubations, although both gases were produced from organic matter additions. Further experimentation was undertaken to investigate the possibility that the soil lacked either an indigenous microflora capable of metabolizing PCB or a suitable substrate analog which promoted their activity or growth. Inoculation with Acinetobacter P6 (Furukawa) alone did not enhance mineralization of 14C‐PCB. However, when enriched with substrate analog biphenyl, 20 to 27% of the label was recovered as 14CO2 over a 63‐d period compared to < 1% 14CO2 for the unenriched controls. Uninoculated and enriched treatments also greatly enhanced mineralization yielding 15 to 20% as 14CO2, yet the extent of primary degradation of PCB (i.e., disappearance) was greater when both Acinetobacter and biphenyl were added. Analog enrichment with biphenyl is the most important factor effecting PCB degradation in soil, but additional enhancement is brought about by inoculation with Acinetobacter, which is superior to the indigenous microflora with respect to diversity towards metabolism of the isomers present in Aroclor 1242.
Soil Tests for Estimating Labile, Soluble, and Algae‐Available Phosphorus in Agricultural Soils
Authors: Wolf A. M. , Baker D. E. , Pionke H. B. , Kunishi H. M.
Published: July 2010

The relationships of three “quick” soil tests for P (Olsen, Bray‐1, and Mehlich I) with labile P, the equilibrium phosphorus concentration in the soil solution (EPC) and algae‐available P (as determined by 0.1 M NaOH extraction) were examined for a diverse group of noncalcareous agricultural soils. The soils were collected from 19 states in the southeast, north central, and northeast regions of the United States. In general, good relationships were obtained when soils were grouped according to geographic location. All soil tests were good predictors of labile P for the north central soils and for soils from Ohio and Pennsylvania (r2 ≥ 0.92). On the southeastern soils, the best relationships were found between labile P and the Olsen and Mehlich I soil test P measurements (r2 ≥ 0.90) after further separation of the soils into textural groups. Good relationships were found between EPC and the three soil test P measurements for the north central soils (r2 ≥ 0.80) and for the southeastern soils (r2 ≥ 0.71). For the soils from Pennsylvania and Ohio, Bray‐1 was the best predictor of EPC (r2 = 0.94). The relationships between algae‐available P and the soil test P and labile P measurements varied with the “active” Fe and Al content of the soils, although significant relationships between the parameters were developed for the north central soils (r2 ≥ 0.71) and for the southeastern soils separated into groups of low and high active Al contents (r2 ≥ 0.67).
Nutrient Runoff Losses as Predicted by Annual and Monthly Soil Sampling
Authors: Sharpley A. N. , Smith S. J. , Berg W. A. , Williams J. R.
Published: July 2010

The transport of soluble and particulate P and N in runoff from several cropped and grassed watersheds in Oklahoma and Texas was related to the nutrient content of surface soil (0–50 mm) sampled monthly and annually (March) over a 2‐yr period in an effort to improve the prediction of nutrient transport. For both monthly and annual soil samplings, the prediction of soluble P was good for events > 0.75 mm runoff (r values ranged from 0.57 to 0.92), but smaller events were poorly predicted. The nitrate content of runoff was not closely related to surface soil content (r vlaues ranged from 0.17 to 0.58), precluding its accurate prediction in runoff. Prediction of both particulate P and total N concentrations of individual runoff events was improved using separate equations for grassed and cropped watersheds compared to a general equation. Even so, predicted mean annual flow‐weighted concentrations and amounts of soluble P, particulate P, and total N using either monthly or annual soil nutrient data were significantly related to measured values at the 0.01 level and above (r values ranged from 0.57 to 0.97). Results indicate that seasonal variation in soil nutrient content had less effect on the predictive equations than rainfall and management characteristics. Consequently, these characteristics must be accounted for before the transport equations can be reliably used on an individual runoff event basis.
Reduction of Hexavalent Chromium in Water Samples Acidified for Preservation
Authors: Stollenwerk K. G. , Grove D. B.
Published: July 2010

Reduction of hexavalent chromium, Cr(VI), in water samples, preserved by standard techniques, was investigated. The standard preservation technique for water samples that are to be analyzed for Cr(VI) consists of filtration through a 0.45‐µm membrane, acidification to a pH < 2, and storage in plastic bottles. Batch experiments were conducted to evaluate the effect of H+ concentration, NO2, temperature, and dissolved organic carbon (DOC) on the reduction of Cr(VI) to Cr(III). The rate of reduction of Cr(VI) to Cr(III) increased with increasing NO2, DOC, H+, and temperature. Reduction of Cr(VI) by organic matter occurred in some samples even though the samples were unacidified. Reduction of Cr(VI) is inhibited to an extent by storing the sample at 4°C. Stability of Cr(VI) in water is variable and depends on the other constituents present in the sample. Water samples collected for the determination of Cr(VI) should be filtered (0.45‐µm membrane), refrigerated, and analyzed as quickly as possible. Water samples should not be acidified. Measurement of total Cr in addition to Cr(VI) can serve as a check for Cr(VI) reduction. If total Cr is greater than Cr(VI), the possibility that Cr(VI) reduction has occurred needs to be considered.
Combined Effects of Peroxyacetyl Nitrate and Ozone on Growth of Four Tomato Cultivars
Authors: Temple P. J. , Taylor O. C.
Published: July 2010

In a greenhouse exposure chamber study to determine the combined effects of peroxyacetyl nitrate (PAN) and ozone (O3) on foliar injury and growth of four cultivars of tomato (Lycopersicon spp.), 4‐week‐old plants were exposed to 0, 125, and 250 µg m−3 PAN and 0, 200, and 400 µg m−3 O3, and all combinations, 4 h/d, once per week for 3 weeks. Plants were harvested 1 week after the last exposure. The experiment was repeated twice. Ozone induced trace (ca. 1%) foliar injury at 200 µg m−3 and moderate (30–50%) foliar injury at 400 µg m−3. Peroxyacetyl nitrate caused no foliar injury development, either alone or in combination with O3, and had no effect on O3 injury. Foliar injury on the four cultivars increased in the order ‘Heinz 1350,’ ‘Tiny Tim,’ ‘Ace,’ and ‘Pyxie.’ Ozone by itself produced a significant linear reduction in growth of the four cultivars. Plants exposed to PAN alone also showed reduced growth but results were not statistically significant at the 0.05 level. Combinations of O3 and PAN had less than additive effects on growth reduction, but greater than additive effects on shoot/root ratios. This difference was attributed to greater suppression of root growth relative to leaf growth induced by O3‐PAN mixtures.
Plant Uptake of Heavy Metals in Zinc Fertilizers Made From Industrial By‐Products
Authors: Mortvedt J. J.
Published: July 2010

Many industrial by‐products are being marketed as micronutrient fertilizers because of regulations which restrict indiscriminate disposal of wastes. Some of these materials contain other heavy metals which might be absorbed by crops and thus possibly enter the human food chain. Two greenhouse pot experiments were conducted to determine if corn (Zea mays L.) and Swiss chard (Beta vulgaris L.) absorbed significant quantities of Cd, Ni, and Pb from Zn fertilizers prepared from industrial by‐products. Corn forage yields increased with Zn applications on alkaline (pH 7.4) but not on acid (pH 5.8) Mountview silt loam (Typic Paleudults). Concentrations of Cd in immature corn forage were not affected by applications of Zn fertilizers containing from 1 to 2165 mg kg−1 of Cd. Dry matter yields of several harvests of Swiss chard were not affected by Zn applications at either soil pH level. Zinc concentrations in plant tissue increased with Zn applications but were lower in both crops grown on alkaline soil than in those grown on acid soil. Plant uptake of Cd generally increased with increasing levels of Cd in the Zn fertilizers on the acid soil only, with some concentrations > 2 mg kg−1 in chard tissue grown on acid soil. Uptake of Ni and Pb by both crops generally was not affected, even with Ni and Pb levels in some by‐products as high as 8950 mg kg−1 and 52 000 mg kg−1, respectively. These results suggest that plant uptake of heavy metal contaminants in Zn fertilizers made from some industrial by‐products is minimal, except for Cd in some leafy vegetables grown on acid soils. Since corn and most vegetable crops usually are not fertilized with Zn if grown on acid soils, plant uptake of heavy metal contaminants in by‐product Zn fertilizers should not be a significant problem.
Ozone and Sulfur Dioxide Effects on Tall Fescue: II. Alteration of Quality Constituents
Authors: Flagler R. B. , Youngner V. B.
Published: July 2010

A greenhouse study was conducted to determine whether ozone (O3) and sulfur dioxide (SO2) might alter forage quality parameters of tall fescue (Festuca arundinacea Schreb. ‘Alta’). Plants were exposed weekly to four O3 treatments, 0, 0.10, 0.20, and 0.30 µL L−1; with or without 0.10 µL L−1 SO2, 6 h d−1 for 12 weeks. Ozone had a much greater impact on forage quality than did SO2. Ozone increased protein content on a g kg−1 basis and decreased protein on a weight per plant basis. Ozone reduced crude fat, crude fiber, and total nonstructural carbohydrate contents of the forage. Crude ash content increased due to O3 exposure. On a weight per plant basis, O3 decreased the forage concentration of Ca, Mg, and P. Ozone increased Ca concentration of herbage. Sulfur dioxide increased ash content of the forage. Phosphorus concentration and weight per plant of Mg and P were all reduced by SO2. Significant pollutant interactions occurred for crude fiber, crude ash, total Mg, and total P contents of forage. While treatments resulted in some apparent increases in forage quality, these were at the expense of yield. The most adverse effects on forage quality were an increase in ash content which resulted from an interaction of SO2 with O3, and a reduction in soluble carbohydrate content of shoots due to O3.
Riparian Losses of Nitrate from Agricultural Drainage Waters
Authors: Jacobs T. C. , Gilliam J. W.
Published: July 2010

Increased nutrient levels in surface streams and eutrophication of some Coastal Plain waters has led to inquiries about both the amount and control of nitrate losses from agricultural fields. Nitrate concentrations in shallow groundwaters beneath cultivated fields and in the drainage waters from those fields were examined to determine the fate of nitrogen lost to drainage waters. From a Middle Coastal Plain watershed where well‐ and moderately well‐drained soils dominate agricultural fields, 10 to 55 kg ha−1 yr−1 NO3‐N moved from the fields in subsurface drainage water. However, most fields are bordered by forested buffers between the cultivated areas and streams which consist of poorly and very poorly‐drained soils covered by dense vegetation. The evidence strongly indicated that a substantial part of the nitrate in the drainage water was denitrified in the buffer strip and that assimilation by vegetation was insignificant. Buffer strips of < 16 m were effective for inducing significant losses of nitrate before drainage water reached the stream. A field containing subsurface drainage tubing which emptied into open ditches moved more nitrogen into surface water than those fields without subsurface drainage improvements. From a Lower Coastal Plain watershed, a dense clay layer below the surface horizon reduced subsurface drainage resulting in total losses from the field of only 6 to 12 kg ha−1 yr−1 NO3‐N. These losses were mostly in surface runoff. The extensive floodplain of the natural stream had a high capacity to reduce large quantities of N but the low total loss from the watershed is largely a result of low input to the drainage water from nonpoint sources. Soils included in this study were Typic Paleudults, Arenic Paleudults, Aquic Hapludults, and Aeric Paleaquults.
The Effect of Nitrilotriacetic Acid on the Solubilities of Metals in Soil‐Sludge Mixtures
Authors: Garnett K. , Kirk P. W. W. , Lester J. N. , Perry R.
Published: July 2010

Batch experiments were undertaken to determine the effect of nitrilotriacetic acid (NTA) on the solubilities of Cu, Mn, Ni, Pb, and Zn in soil/sludge mixtures. Soil samples from Wye Coombe series (silt‐loam, Rendolic Eutrochrepts) and Essex Windsor series (clay‐loam, Haplaquepts) were each mixed with anaerobically digested sewage sludge and the influence of extraction time, NTA concentration, and pH on the solubility of NTA and metals was assessed. Removal of NTA from the liquid phase by soil/sludge colloids became constant after 8 h and was attributed to adsorption. The concentration of soluble Ni, Pb, and Zn increased in both soil/sludge mixtures with increases in NTA concentration from 0 to 0.212 mmol L−1. Manganese was the least affected by the addition of NTA, and pH was shown to be the overriding influence on its solubility. In the Essex soil/sludge mixture, increasing the NTA concentration from 0 to 0.005 mmol L−1 caused a sharp decrease in Cu solubility, with higher NTA concentrations having no further effect on soluble Cu levels. Addition of NTA did not significantly change Cu solubility in the Wye soil/sludge mixture. These results provide a basis to design further experiments to determine if increased heavy metal solubility could result if sludge containing NTA was applied to agricultural land.
Picloram Movement in an Appalachian Hardwood Forest Watershed
Authors: Neary D. G. , Bush P. B. , Douglass J. E. , Todd R. L.
Published: July 2010

Picloram (4‐amino‐3,5,6‐trichloropicolinic acid) was applied at a rate of 5.0 kg ha−1 acid equivalent to 4 ha of the 28‐ha Watershed 19, Coweeta Hydrologic Laboratory in western North Carolina. The herbicide was broadcast manually as a pellet formulation (10% acid equivalent) in May 1978. The objective was to eliminate a poor‐quality mixed oak overstory and rhododendron (Rhododendron maximum L.)‐laurel (Kalmia latifolia L.) understory prior to planting white pine (Pinus strobus L.). Picloram residues in samples from an Umbric Dystrochrept soil peaked in concentration in the upper 0.07 m at 11.58 mg kg−1, had a half‐life of about 4 weeks, and declined to near detection limits 28 weeks after application. Soil solution contained the highest picloram levels at 0.6 m (peak of 350 mg m−3). Picloram residues were detected in soil solution 1.2 m into the soil, but concentrations were < 25 mg m−3, and persisted for only 60 weeks. Intensive sampling of two springs detected trace levels for a period of 18 d. Only sporadic, low‐level picloram residues were detected in streamflow from nested 10‐ha and 28‐ha watersheds during a 70‐week period. Use of the herbicide picloram did not affect the quality of streamflow from Watershed 19 for domestic or agricultural purposes.
Simulated Regional Variations in Pesticide Runoff
Authors: Haith Douglas A.
Published: July 2010

Mathematical models for daily weather, hydrology, and soil chemistry were combined in a general approach for estimating pesticide runoff. Runoff losses of atrazine [2‐chloro‐4(ethylamino)‐6‐(isopropylamino)‐s‐triazine] and carbofuran (2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl methylcarbamate) were simulated for hypothetical 9‐ha corn (Zea mays L.) fields in New York, Georgia, Iowa, Texas, and Kentucky. Two representative soils were considered: a well‐drained sandy loam and a poorly‐drained silty clay loam exemplified by a Typic Dystrochrept and Typic Albaqualf, respectively. The two pesticides, five locations, and two soils produced a total of 20 cases. Each case was simulated for 100 yr by a Monte Carlo process to produce 100 samples of annual pesticide runoff. Mean annual pesticide losses ranged from 0.7 to 6.3% of application for atrazine and from 0.8 to 11.4% for carbofuran. Statistical analyses of the samples indicated that soil type affects pesticide runoff, with the silty‐clay loam producing significantly greater losses than the sandy loam. Regional similarities and differences were also identified. New York pesticide losses were significantly lower than those from the other four sites. Conversely pesticide runoff values from Georgia and Texas were statistically similar. Variations in pesticide runoff are largely explained by seasonal runoff volume. Regressions on mean runoff volume during the month of pesticide application explained over 89% of the observed variation in mean annual pesticide in runoff.
Effects of a Glucose‐imposed Oxygen Demand on Land Treatment Systems
Authors: Coody Peter N. , Sommers Lee E. , Nelson Darrell W.
Published: July 2010

Laboratory experiments were conducted to quantify soil and crop interactions in a land treatment system receiving a glucose‐imposed oxygen demand. Synthetic wastewaters were prepared by dissolving sufficient glucose in a plant nutrient solution to provide four levels of chemical oxygen demand (COD). The solutions were applied to soil columns cropped to reed canarygrass (Phalaris arundinacea L.) to provide a COD of 0 to 180 mmol O2 column−1 week−1. The columns received the glucose for 25 weeks and were monitored for the composition of the soil atmosphere, plant yields, water use, and COD removal. The added COD elevated CO2 concentrations in the soil atmosphere to over 480 times atmospheric levels. This coincided with a depletion of O2 in the soil atmosphere, where a minimum concentration of 0.3 mol O2 m−3 was observed. Average plant yields ranged from 2.8 to 20.3 g column−1 and were inversely proportional to the COD added. Water use ranged from 11.4 to 26.9 cm column−1 week−1 and was directly related to the reduction in plant growth caused by the COD loading. Greater than 97% of the added COD was removed by the simulated land treatment system.
Response of Soybean to Low Concentrations of Ozone: I. Reductions in Leaf and Whole Plant Net Photosynthesis and Leaf Chlorophyll Content
Authors: Reich P. B. , Schoettle A. W. , Raba R. M. , Amundson R. G.
Published: July 2010

Since most commercially grown soybean plants in the USA are subjected to low or moderate levels of ambient O3 pollution it is important to understand whether exposure to O3 influences CO2 exchange in this species. Therefore, for 8 weeks soybean (Glycine max cv. Hodgson) plants were exposed to O3 for 6.8 h daily in controlled environment chambers. Four treatments were used: 0.01, 0.05, 0.09, and 0.13 µL L−1 O3 in filtered air. Net photosynthesis (Pn), dark respiration, and chlorophyll content were measured in all treatments for both individual leaves of various ages and for whole plants. Measurements of CO2 exchange were made nondestructively with an infrared gas analysis system using either plexiglass cuvettes (leaves) or continuously stirred tank reactors (plants). The Pn of whole plants was reduced by 10, 11, and 22% in the 0.05, 0.09, and 0.13 µL L−1 treatments, respectively, compared with the 0.01 µL L−1 treatment. Among individual leaves of similar ages, exposure to O3 also resulted in declines in Pn and this occurred at all leaf ages. There was a significant linear relationship between Pn and O3 concentration for both individual leaves and for whole plants. Chlorophyll contents of whole plants and individual leaves were also reduced by O3 exposure. Chlorophyll content and Pn were correlated with each other for both individual leaves and whole plants. Changes with leaf age were typical for Pn and for chlorophyll content. There was no apparent effect of O3 treatment on dark respiration. The observed reduction in Pn at low levels of O3 (coupled with reports of O3‐induced reduction in growth and yield) suggests that ambient O3 pollution in the USA is currently causing decreased Pn in field‐grown soybean which can lead to a significant loss in yield.
Sewage Sludge as a Coal Mine Spoil Amendment for Revegetation in Colorado
Authors: Topper K. F. , Sabey B. R.
Published: July 2010

Use of digested municipal sewage sludge as an amendment for revegetation of a Colorado coal mine spoil was evaluated as a function of application rate. Plant growth responses to sewage sludge additions were compared to inorganic nitrogen (N) and phosphorus (P) fertilizer treatments on a grass pasture mixture. Sewage sludge additions resulted in significant increases in aboveground biomass and percent canopy cover over the control for two seasons of growth following sludge application. Sewage sludge rates < 83 Mg ha−1 yielded greater plant growth than any of the inorganic N and P fertilizer treatments for both growing seasons. However, the lowest level of sewage sludge (14 Mg ha−1) resulted in equivalent total N and total P concentrations of the seeded grasses when compared to the highest inorganic fertilizer treatments. The superior growth associated with sewage sludge additions at less than 83 Mg ha−1 was likely due to measured increases in nutrient availability, improved physical condition of the spoil and a possible stimulation of microbial activity. The highest level of sewage sludge (83 Mg ha−1) was detrimental to seeded grass growth when compared to the lower sludge rates in 1984. This may have been due to increased soluble salt concentrations, an increase in competition by invading annual forbs, and/or elemental toxicities. Further research is necessary to determine the exact causes.
Forms of Solid Phase Copper in Copper‐enriched Swine Manure
Authors: Miller W. P. , Martens D. C. , Zelazny L. W. , Kornegay E. T.
Published: July 2010

Manure from swine fed high levels of copper (Cu) was extracted sequentially and nonsequentially with reagents designed to selectively solubilize specific Cu forms from the manure. Fresh (slurry), freeze‐dried, and oven‐dried samples were used. Water‐soluble Cu increased from 2% to 30% with increasing severity of drying. Salt solutions [calcium (Ca) and lead (Pb)] were no more effective than H2O in extracting Cu, suggesting both a lack of Cu adsorbed on inorganic mineral surfaces (which were composed largely of quartz, calcite, and gypsum), and a strong binding of the Cu against Pb‐exchange, presumably with organic material. Dilute acetic acid (pH 2.5) removed 67% of the Cu from oven‐dried samples, but only 7 to 11% from the slurry or freeze‐dried samples. This suggests that Cu oxide and hydroxide minerals, which are soluble in this reagent, were not present in the fresh, slurried manure, but that oven‐drying of the manure affects chemical forms of Cu in a significant fashion. Most of the Cu in all the manure samples was extractable with sodium hydroxide (NaOH) or potassium pyrophosphate (K4P2O7), suggesting association with organics. Little Cu remained after sequential K4P2O7 extraction, at which point CuS minerals would be expected to remain in the residue. It was concluded that Cu minerals are probably not found in this waste, but that most, if not all, of the Cu is associated with the organic fraction.
Effects of Trace Elements and Pesticides on Dephosphorylation of RNA and DNA Added to Soils
Authors: Frankenberger W. T. , Johanson J. B. , Lund L. J.
Published: July 2010

Nucleic acids are rapidly degraded in soil releasing purine and pyrimidine bases and orthophosphate (Pi). This study was carried out to assess the effects of 14 trace elements, 12 herbicides, and two fungicides on dephosphorylation of yeast ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) added to soils (Xerollic Calciorthids and Typic Haploxeralfs). The cumulative amount of Pi released from nucleic acids increased linearly with time of incubation (up to 72 h), decreased with profile depth, and was highly influenced by soil pH. When trace elements were applied and compared by using 2.5 mmol kg−1 of soil, the average inhibition in dephosphorylation of RNA and DNA in two soils ranged from 17% with Co(II) to 52% with Cu(II). The most effective inhibitors of nucleic acid dephosphorylation were Ag(I), Cu(I), Cd(II), Cu(II), Mn(II), Ni(II), and Pb(II) (avg inhibition ≥ 35%). Other elements that inhibited dephosphorylation of RNA and DNA added to soils included Ba(II), Co(II), Hg(II), Zn(II), Ti(IV), V(IV), and W(VI). When the pesticides were compared by using 5 mg of active ingredient kg−1 of soil, the average inhibition in nucleic acid dephosphorylation ranged from 14% with butylate to 39% with chloramben. The most effective inhibitors (> 25%) were atrazine, naptalam, chloramben, dicamba, trifluralin, and maneb. Other pesticides that inhibited RNA and DNA dephosphorylation in soils included cyanazine, 2,4‐D, dinitroamine, EPTC plus R‐25788, alachlor, paraquat, butylate, and captan.
Solubility Relationships and Mineral Transformations Associated with Recarbonation of Retorted Shales
Authors: Reddy K. J. , Lindsay W. L. , Boyle F. W. , Redente E. F.
Published: July 2010

Oil shales are heated at high temperatures to obtain oil. During this process carbonate minerals are destroyed by driving off CO2(g) and large amounts of waste materials (retorted shale) are produced. The pH of such retorted shales often approaches 12.0. With time, the pH of these materials will drop by attaining equilibrium with calcite (CaCO3) and atmospheric carbon dioxide (recarbonation). The objective of this paper was to examine solubility relationships and mineral transformations associated with recarbonation of retorted shales. Carbon dioxide gas (CO2[g]) was bubbled through two shale samples, one retorted by Los Alamos National Laboratory (LANL) and another retorted by Lurgi Ruhrgas (Lurgi) to lower their pH. X‐ray diffraction analysis was used to identify different mineral phases of retorted and recarbonated shales. The results show that recarbonation caused silicate minerals to dissolve, CaCO3 to precipitate, and lowered pH from approximately 12.0 to 8.0. Solubility measurements showed that upon recarbonation Ca2+ activity for both shales approached equilibrium with CaCO3 and measured CO2(g). Initially Mg2+ activity appeared to be in equilibrium with either diopside (CaMg[SiO3]2) or antigorite (Mg2.825Si2O5(OH)3.65) and measured silica, but not with dolomite (CaMg[CO3]2) nor magnesite (MgCO3). After 20 d of recarbonation for LANL, Mg2+ solubility decreased from 10−2.78 M to 10−3.15 M. The experimental findings in this study further suggest that bubbling CO2(g) through retorted shales can reduce the concentrations of F and, in some cases Mo, in leachates.
Field Chambers for Assessing Crop Loss from Air Pollutants
Authors: Musselman R. C. , Mc Cool P. M. , Oshima R. J. , Teso R. R.
Published: July 2010

A new field fumigation facility has been developed for determining effects of air pollutants on crops. The permanent facility consists of closed‐top, octagonal chambers 2.1 m tall by 2.5 m across. Each chamber is supplied with air via underground ducting from two centralized blowers, one charcoal‐filtered and the other nonfiltered. Individual chambers can be adjusted to 100% filtered air for fumigation with specific levels of pollutants, or a pollutant gradient can be generated by combining filtered and ambient air. Air exchange rates through the chambers are also adjustable. Each chamber is constructed of several flat aluminum‐frame panels covered with Teflon film which has remained clear and durable after three years of continuous service. Panels are easily removed for repair if necessary. Teflon film walls minimize environmental differences between chamber and ambient air. Chamber temperatures closely track ambient, but are higher than ambient at midday. Temperatures remain uniform at different locations within each chamber. Light intensity within chambers averages 11% less than ambient. Pollutant levels set within each chamber remain relatively stable in both time and space. Native soil under each chamber has been replaced with a standard greenhouse soil mix which is irrigated with a drip system. The fumigation facility is comparable in construction costs to open‐top fumigation chamber systems, and is especially useful for experiments requiring precise control of pollutant levels.
The Effects of Tailing Dam Profiles on Relative Wind Erosion Rates
Authors: Coffey P. S. , Scott W. D. , Summers K. J.
Published: July 2010

Erosion from mine treatment and associated residue areas can pose a significant environmental problem for surrounding locations from dust and other transported materials. The shape of such residue areas can influence windfield behaviour by causing significant wind speed increases. Residue areas are often unprotected so that increasing the speed of wind passing over these areas will cause extra erosion. Values of wind speed‐up predicted by an empirical model for wind flow over hills of low slope were compared with measured values over approach slopes to tailings dam. Hunt's model used in this study relates wind speed from a point on the hill to that observed if there was no hill. Measured values are in agreement with those predicted by the model. Shear stress values calculated from the wind flow model are then used to determine the friction velocity which, in turn, predict the relative rates of erosion. This prediction is based on the cubic relation between the friction velocity and erosion rate observed by Bagnold. These calculations are repeated for the various possible hill shapes allowed by the plant layout and the need to integrate long term spoil heaps with existing topography. A strategy for minimizing erosion of mine tailings through shape selection can then form part of the environmental considerations associated with tailings dams.
Fate of Diclofop‐methyl After Application to a Wheat Field
Authors: Smith A. E. , Grover R. , Cessna A. J. , Shewchuk S. R. , Hunter J. H.
Published: July 2010

Dissipation of diclofop‐metnyl, the methyl ester of the herbicide diclofop ((±)‐2‐[4‐(2,4‐dichlorophenoxy)phenoxy] propanoic acid), and its acid metabolite (diclofop) in atmospheric, agronomic, and edaphic components were measured in a wheat (Triticum aestivum L.) field during and following application on 29 June 1982. Drift losses during application were <0.1% of the applied herbicide. Air samples, collected at six heights (ranging from 30–200 cm) above the crop canopy during the first 7 d after application did not show measurable levels of diclofop‐methyl, thus indicating minimal losses due to volatilization. The crop canopy intercepted 21% of the applied ester. On entry into the crop, the ester was rapidly hydrolyzed to the metabolite diclofop acid, so that after 5 d only 2% of the intercepted ester could be solvent washed from the treated wheat. At first there appeared to be a rapid metabolism of diclofop acid in the wheat, with approximately 5% of initially applied ester remaining in the acid form after 5 d. Thereafter, the rate of loss of the acid was slower, but metabolism of the diclofop acid was essentially complete after 32 d. No diclofop ester or acid was detected in the wheat straw or grain at harvest 88 d after application. In the soil, hydrolysis of the methyl ester to diclofop acid was rapid and complete within 9 d of application. The acid underwent slow breakdown in the field soil and on 14 October, 126 d after application, 19% of the initial herbicide treatment was still present in the top 7.5‐cm soil depths as diclofop acid.
Boron Deposition on Soil and Native Vegetation from Geothermal Emissions
Authors: Lang F. J. , Bingham F. T. , Hendrix F. F. , Crane N. L.
Published: July 2010

Boron deposition, soil B, and foliage B were sampled in a field study around two geothermal generating units with different operating histories; the study also determined relative sensitivities of several native tree species to B in soil and foliage. Boron emissions from the older cooling tower, operational for 11 yr, were nearly 5 times greater than emissions from the newer cooling tower, operational for 2.5 yr. This difference was due to substantially greater B concentrations in circulating water at the older unit. Boron deposition was as great as 129.6 kg ha−1 yr−1 at the older unit and 4.2 kg ha−1 yr−1 at the newer unit. Soil B (saturation extract) was as great as 44.0 mg L−1 at the older unit and 0.6 mg L−1 at the newer unit. At a given rate of B deposition, soil B was more than 4 times greater at the older unit due to its longer operating history. At a given soil B level, the deciduous bigleaf maple (Acer macrophyllum Pursh) contained double the foliage B of the broadleaf evergreen, interior live oak (Quercus wislizeni A. DC.), and about 5 times greater foliage B than the conifer, Digger pine (Pinus sabiniana Dougl.). Foliage B thresholds for detectable levels of visible injury due to B toxicity were about 500 mg kg−1 for both bigleaf maple and interior live oak. These relationships suggest that more rapid B accumulation is responsible for higher levels of visible injury due to B in bigleaf maples than in other native tree species.