bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of Corn and Soybeans to Soil vs. Foliar‐Applied Salts of Cooling Tower Origin
Authors: Armbruster James A. , Mulchi Charles L.
Published: July 2010

Field studies were conducted on corn (Zea mays L.) and soybeans [Glycine max (L.) Merr.] during 1976 and 1977 to acquire information on the response of crops to saline aerosol deposition near brackish water cooling towers in combination with salt accumulation in the soil.

Salt treatments imposed included preplant soil applications equal to 0, 14, 28, 56, and 112 kg NaCl ha−1 and foliar applications of brackish cooling tower water as saline aerosol drift equal to 0, 34, and 68 L ha−1 d−1. Total soluble salt in the foliar treatments averaged 23 ± 3 g L−1, with average weekly salt deposition rates of 0, 3.8 ± 0.6, and 7.6 ± 1.2 kg ha−1. Information on elemental contents in leaves at flowering, leaf injury ratings, and grain yields were obtained. Information on extractable P, K, Ca, Mg, and Na plus electrical conductivity (EC) and pH of 0‐ to 15‐cm soil samples was obtained in October 1977 following two summers of treatments on the same plots and again in April 1978.

For both crops, leaf Na and Cl, metabolic index, leaf injury ratings, and grain yields were significantly (P ≤ 0.05) affected by foliar salts in both years. However, soil salt treatments influence only leaf Cl contents and metabolic index values. Grain yields were reduced an average of 10 and 9% of controls at the highest foliar salt rate in corn and soybeans, respectively.

Significant (P ≤ 0.05) increases in extractable Na in soils were found with foliar salt treatments. Increases in extractable Ca and pH (P ≤ 0.05) and K, Mg, and Na (P ≤ 0.1) were observed with increased soil salt rates. However, no differences were found among soil chemical parameters 8 months following the termination of the foliar treatments. The soils data suggest that salt deposition within 10 km of the Chalk Point cooling towers would cause minimal impact due to the sandy textures of the soils and annual rainfall in excess of 100 cm yr−1.
Macronutrient and Boron Ratios in Tall Fescue: Relationship to Yields on Pyritic Coal Wastes
Authors: Lewis B. G.
Published: July 2010

A previous greenhouse study had demonstrated that yield of tall fescue (Festuca arundinacea Schreb.) grown directly on a pyritic waste was not significantly different from yield on a soil despite low tissue concentrations of P and K in the waste‐grown plants. In an attempt to explain this result, and to determine if this phenomenon was typical of such wastes, a greenhouse study was carried out with pyritic wastes from five disposal sites for coal‐cleaning refuse in southern lllinois. The wastes and an agricultural soil (Elliott silt loam: fine, illitic, mesic Aquic Arguidolls) were treated with limestone (to pH 6.5) and fertilizers. Yields of 8‐week‐old shoots of tall rescue grown on the wastes were significantly lower than yield of plants grown on the soil when the Ca/B ratio in the shoots was outside a range of 1.7 to 2.8 (where Ca/B is the ratio of log10 concentrations of Ca and B expressed as microgram‐atoms per gram dry matter). Within this range, yields were not significantly different from yield on the soil despite significantly lower concentrations of P and K in the shoots of the waste‐grown plants. It is suggested that elemental interactions should not be ignored in reclamation of waste sites, particularly where “trace” element concentrations are either higher or lower than concentrations in typical soils. Results also suggest a P‐ and K‐sparing effect of elevated B concentrations in tall rescue.
Effect of Sulfur Dioxide on Woody Boreal Forest Species Grown on Native Soils and Tailings
Authors: Addison P. A. , Malhotra S. S. , Khan A. A.
Published: July 2010

A study was carried out on the influence of 15.2 µmol m−3 (0.34 ppm) (Canadian maximum acceptable limit) of SO2 on net CO2 assimilation rate (NAR) and visible symptom development of several boreal forest woody species. Fumigation with SO2 significantly reduced NAR in all species and produced visible symptoms of injury in 2 to 20 d. The decrease in NAR of deciduous species {aspen (Populus tremuloides Michx.), willow (Salix sp.), green alder [Alnus crispa (Ait.) Parsh], and paper birch (Betula papyrifera Marsh)} was significantly more rapid than of conifers { jack pine (Pinus banksiana Lamb.), white spruce [Picea glauca (Moench) Voss], and black spruce [P. mariana (Mill.) BSP]} or an evergreen angiosperm [Labrador tea (Ledum groenlandicum Oeder)] when grown on a fertilized Brunisol. cases did not appear until NAR had decreased considerably. The response of these metabolic and visible responses appeared to be related to differences in S uptake owing in part to higher gas exchange rates for deciduous species than for conifers.

Conifers growing in oil sands tailings responded to SO2 with a significantly more rapid decrease in NAR as compared with those growing in the Brunisol. Because both soils were fertilized, nutrient status was ruled out as a cause. It is suggested that the conifers obtained from the railings dike were predisposed to SO2 fumigation by either the presence of toxic material in the tailings sand or their history of exposure to moderate levels of SO2. Sulfur uptake and visible symptom development were not different on tailings as compared with the Brunisol.
Erosion of Earth Covers Used in Shallow Land Burial at Los Alamos, New Mexico
Authors: Nyhan J. W. , Depoorter G. L. , Drennon B. J. , Simanton J. R. , Foster G. R.
Published: July 2010

The Los Alamos National Laboratory and the USDA‐ARS examined soil erosion and water balance relationships for a trench cap used for the shallow land burial of low‐level radioactive wastes at Los Alamos, NM. Eight 3.05 by 10.7 m plots were installed with bare soil, tilled, and vegetated surface treatments on a 15 by 63 m trench cap constructed from soil and crushed tuff layers. A rotating boom rain simulator was used to estimate the soil erodibility and cover‐management factors of the Universal Soil Loss Equation (USLE) for this trench cap and for two undisturbed plots with natural vegetative cover. The implications of the results of this study are discussed relative to the management of infiltration and erosion processes at waste burial sites and compared with similar USDA research performed throughout the USA.
Soil Cation Leaching by “Acid Rain” with Varying Nitrate‐to‐Sulfate Ratios
Authors: Huete A. R. , Mc Coll J. G.
Published: July 2010

The influence of the anion composition of simulated “acid rain” on cation leaching of three soils with different surface‐charge properties was examined. Four acid mixtures of H2SO4 and HNO3, all with pH 3.5, but with varying NO3−/SO42− mole ratios of 1.00:0.00, 0.75:0.25, 0.55:0.45, and 0.00:1.00, were used to leach an Ultic‐Alfisol, an Oxisol, and an Entisol. The taxonomic names of these three soils are (i) Cornutt series: fine, mixed, mesic Ultic Haploxeralfs, (ii) unnamed Rhodustox, and (iii) Hanford series: coarse‐loamy, mixed, nonacid, thermic Typic Xerorthents. The Alfisol had a high SO42− adsorption capacity because of its high Fe2O3 content of 12 g kg−1 and high point‐of‐zero charge (PZC) of 6.0. The Oxisol, although strongly weathered, had a lower Fe2O3 content of 5 g kg−1 and PZC of 4.5. The Entisol was a relatively unweathered soil derived from silicaceous alluvium, with even less Fe2O3 of 3 g kg−1 and a lower PZC of 3.5, and represented a soil of fixed charge. Cation leaching of the Alfisol varied directly with the NO3− content of the leaching input due to the higher mobility of NO3− compared with SO42− that was adsorbed. The relative NO3−/SO42− contents of inputs had no effects on cation leaching of the Entisol. Effects on leaching of the Oxisol were intermediate between those of the Alfisol and Entisol. It was clearly demonstrated that the anion composition of “acid rain” plays a significant role in the cation leaching of soils with amphoteric‐charge properties, which are able to adsorb S42−. Some practical implications are also discussed.
Chemical Partitioning of Cadmium, Copper, Nickel and Zinc in Soils and Sediments Containing High Levels of Heavy Metals
Authors: Hickey M. G. , Kittrick J. A.
Published: July 2010

Three soils and a sediment which had undergone prior massive additions of heavy metals were sequentially extracted so that Cd, Cu, Ni, and Zn could be partitioned into five operationally defined geochemical fractions: exchangeable, bound to carbonates, bound to Fe‐Mn oxides, bound to organic matter, and residual. Metal recoveries were within ± 10% of the independently measured total Cd, Cu, Ni, and Zn concentrations. The highest amount of Cd (ca. 37%) was foand in the exchangeable fraction, and Cu was the only metal significantly associated with the organic fraction. The Fe‐Mn oxide fraction contained 23, 24, 26, and 39%, and the residual fractions 15, 34, 55, and 14% of the Cd, Cu, Ni, and Zn, respectively. The amount of Cd in the residual fraction was 50 times higher than typical for unpolluted soils. Assuming that mobility and biological availability are related to the solubility of the geochemical form of the metals and decreases in the order of extraction, the apparent mobility and potential metal bioavailability for these highly contaminated soils and sediment is: Cd > Zn > Cu ≅ Ni.
Relative Toxicity of Heavy Metals to Red Pine Pollen Germination and Germ Tube Elongation
Authors: Chaney William R. , Strickland Richard C.
Published: July 2010

Heavy metals are known to affect vegetative growth of plants, but little is known concerning the effects of these environmental pollutants on reproductive processes. Hence, the effects of Cd2+, Hg2+, Pb2+, Cu2+, Zn2+, and Ba2+ on red pine (Pinus resinosa Ait.) pollen germination and germ tube elongation were determined in vitro in a series of nine aqueous solutions with concentrations that ranged from 0.56 µmol L−1 to 71.16 µmol L−1 for each cation. Large differences among metals in inhibition of the two growth parameters were found. Based on the lowest concentration significantly inhibiting germination, Cd2+ was the most toxic ion followed by Cu2+ > Hg2+ > Pb2+ ≫ Zn2+ > Ba2+. Similarly, the order for metal inhibition of tube elongation was Cd2+ > Pb2+ > Hg2+ = Cu2+ ≫ Zn2+ > Ba2+. Compared with the other ions, Zn2+ and Ba2+ were relatively nontoxic. The concentration (effective dose) of each metal necessary to produce a 10% reduction of germination and tube elongation (ED10) was calculated from linear regression equations. The ED10 for germination for Cd2+ was 0.27 µmol L−1 and was 2.2, 2.5, and 19.0 times less than the ED10 for Hg2+, Cu2+, and Pb2+, respectively. In comparison, the Cd2+ ED10 for germ tube growth was 1.00 µmol L−1. Although the concentrations of Cd2+, Hg2+, and Pb2+ that produced inhibitory effects in vitro occur in the environment, extrapolation of these results to in vivo conditions is cautioned.
Mined Land Reclamation Using Polluted Urban Navigable Waterway Sediments: III. Experience at a Demonstration Site
Authors: Van Luik A. , Harrison W.
Published: July 2010

Eroding ridges of acidic coal‐mine spoil near Ottawa, IL were leveled to form a gently sloped raised plateau. Four test plots were constructed: a control plot and three treatment plots that received a 0.9‐m thick cover of dredged material. Two of the treatment plots received lime applications, and all plots were seeded with a mixture of grasses. Porous ceramic cup soil water samplers were installed, in duplicate, at two levels in the control plot and at three levels in each treatment plot. The three levels in the treatment plots coincided with dredged material, the dredged material/mine spoil interface, and the underlying mine spoil. Nineteen water‐quality parameters were monitored during the 4 yr of the study. Results showed that the near‐surface soil‐water in the control plot deteriorated with respect to pH during the first 2 yr and stabilized thereafter. The deeper control‐plot samples showed no significant change in soil‐water quality. The dredged material soil‐water pH decreased slightly after placement, with the onset of lush vegetative growth. The solutions collected from the dredged material/mine spoil interface were neutralized during the first 2 yr of the study, and dissolved trace metal levels dropped significnatly during the first and succeeding years. The applied dredged material has significantly ameliorated the acidity and trace‐metal levels of water in the underlying mine spoil, and appears to be an effective and safe reclamation medium, under proper use and management.
Land Application of Sewage Sludge with Regard to Cropping Systems and Pollution Potential
Authors: Higgins Andrew J.
Published: July 2010

Aerobically digested liquid sewage sludge was applied to Sassafras sandy loam soils (Typic Hapludults), characteristic of the eastern coastal plain, for 3 consecutive years. Sludge was applied at rates of 0, 22.4, and 44.8 Mg of dry solids/ha in June of each year. Groundwater, soil, and crops were monitored for 4 yr to establish the effects of high rates of sludge application.

The results indicate that sludge application of 22.4 Mg of dry solids/ha on Sassafras sandy loam soil, or other similar sandy loam soils, is the upper limit to ensure protection of the groundwater quality. Annual applications of sludge at 44.8 Mg of dry solids/ha resulted in gross contamination of the groundwater by NO3−‐N and other salts. However, no contamination of the groundwater by heavy metals was detected at either sludge loading rate. Fecal coliform levels were low throughout the duration of the study. Zinc and copper accumulated in the A soil horizon; however, no accumulation occurred in the B horizon. Corn (Zea mays) and rye (Secale cereale) yields were greatly enhanced by the addition of sludge but there was little difference in yield between the sludge loading rates. Uptake of heavy metals in the corn and rye occurred in response to sludge application. Zinc was the only metal that consistently appeared at levels above the control.
Nitrous Oxide Emission from Forest, Marsh, and Prairie Ecosystems
Authors: Goodroad L. L. , Keeney D. R.
Published: July 2010

Measurements of N2O emissions from seven natural ecosystem sites in the University of Wisconsin Arboretum (Madison, WI) were conducted during 1979, 1980, and early 1981. Nitrous oxide emissions during summer and autumn 1979 averaged 0.6, 0.7, 1.5, 7.7, 18.0, 0.2, and 8.5 ng N2O‐N in m−2 s−1 from a burned and an unburned tall‐grass prairie, a deciduous forest, a coniferous forest, a drained and an undrained marsh, and a wet meadow, respectively; the N2O fluxes from the same sites from March to November 1980 averaged 0.6, 0.6, 4.3, 10.1, 41.3, 0.3, and 8.5 ng N2O‐N m−2 s−1, respectively. Although soil temperatures were near freezing, N2O emissions were as high during the spring thaw as they were during the rest of the year. Other N2O flux maxima were observed following periods of heavy rainfall during the summer. The source of inorganic N in these soils is largely mineralization of soil organic matter and plant residue. The quantities of N2O lost and the mechanisms responsible for N2O evolution are a complex combination of environmental and substrate conditions that control mineralization of N as well as subsequent nitrification and possibly denitrification.
Behavior of Elements in the Takahashi, Japan River Basin
Authors: Teraoka Hisayuki , Ogawa Michihiro
Published: July 2010

Concentrations of 22 elements in suspended and dissolved solids in rivers, various sieved particles, and interstitial waters of dam sediments were determined in the Takahashi River Basin on whose estuary stands the Mizushima industrial area, one of the biggest in Japan. In this basin, because of the increased atmospheric pollution, the input of the volatile elements Zn, Cd, Sn, Pb, and Ag from the atmosphere was found to be markedly greater than the theoretical concentration derived from the basin rocks. Copper, chromium, cobalt, iron, nickel, and manganese showed about the same tendencies. These elements were already enriched, even in suspended solids of waters collected near the watershed. Thus, it is suggested that the enrichments of trace elements in suspended solids must occur not only after being suspended in river water, but also in fine solids of topsoil of the watershed. Thus, the increase of trace elements delivered from the atmosphere must bring about the great enrichments in suspended and dissolved solids in river as well as in topsoil and its interstitial water of the river basin.
The Movement of Nitrogen Species Through Three Soils Below Septic Fields
Authors: Brown K. W. , Donnelly K. C. , Thomas J. C. , Slowey J. F.
Published: July 2010

Much effort has been directed toward designing and installing septic leach fields to prevent the contamination of both surface and groundwater. Nitrogen is a very mobile element, abundant in septic effluent, and may pose a serious threat to groundwater below septic fields.

This 2‐yr field study on movement of N species below simulated septic lines in three soils encased in large undisturbed monolith lysimeters was designed to access the potential N pollution of groundwater below septic fields.

Effluent applications of 81.8, 32.7, and 16.4 L/m2 of trench bottom per day were made to sandy loam, sandy clay, and clay soils, respectively. Leachate was collected continuously from suction cups distributed across the lysimeter bottom and occasionally from cups in the soil adjacent to and below the septic line and analyzed for N fractions. At the end of the study, soil samples were collected in an array around the septic line and analyzed for NH4+‐N and total N.

Accumulation of NH4+‐N in the soil profile and leachate losses of NH4+‐N and NO3−‐N were greatest in the sandy loam soil which received the largest volume of effluent and had the lowest CEC. Sixteen months after the initiation of effluent application, NH4+‐N concentrations in the leachate 120 cm below the septic line began to increase above background values, and by 23 months these concentrations were in the order of 6 µg/mL. Vertical movement of NH4+‐N averaged 100 cm/yr in the sandy loam and 25 cm/yr in the sandy clay and clay soils.

Concentrations of NH4+‐N in the leachate samples collected 120 cm below the septic line were > 10µg/mL during and immediately following periods when the soil profile was oxidized.

Soil samples taken at the end of 2 yr of application showed a build‐up of total N under the septic line to concentrations as great as 1000 µg/g. Total N losses summed over the entire period range from 0.45 to 2.2% of that applied.
Microbial Contributions to Soluble and Volatile Arsenic Dynamics in Retorted Oil Shale
Authors: Hassler R. A. , Klein D. A. , Meglen R. R.
Published: July 2010

Arsenic volatilization and solubilization from samples of Paraho and Lurgi retorted shale were evaluated with and without added soybean meal [Glycine max (L.) Merr.], dimethylarsinic acid (DMAA), methanearsonic acid (MAA), and sodium arsenate (SA) in 12‐week experiments. Using a Paraho process shale from an experimental reclamation site in western Colorado, As was only volatilized when nutrients were present, using 23°C incubation. Organic As forms added at 267 × 10−6 mol As kg−1 shale tended to remain more in solution, and were volatilized to a greater extent (45.7 and 6.4 × 10−6 mol kg−1 shale as DMAA and MAA, respectively) than observed with less soluble SA or innate As. Soluble As dynamics were also influenced by nutrient availability. With added DMAA, soluble As levels decreased over the course of the experiment, and decreases followed by rerelease were observed with MAA and SA. The low initial levels of soluble innate As increased slightly over the course of the experiment. In contrast, without nutrients present, other than with added DMAA, the soluble As levels decreased. Incubation at 45°C resulted in a marked reduction of As mobilization, and after heat sterilization, no As mobilization could be observed. Addition of an unsterilized shale inoculum led to a reestablishment of these As mobilization processes in the sterilized samples. In addition, As mobilization was inhibited under anaerobic conditions. With a sample of Lurgi process shale, mobilization in the presence of nutrients was observed, but As volatilization could not be detected, suggesting that variations in oil shale sources and retorting may influence microbial As mobilization. These results suggest that measurable amounts of As can be mobilized from some retorted shale samples, if nutrients are available and environmental conditions allow these processes to occur.
Nitrogen Leaching from Soils Cropped with Sugarcane under the Humid Tropical Climate of Mauritius, Indian Ocean
Authors: Ng Kee Kwong K. F. , Deville J.
Published: July 2010

The significance of N leaching in the N economy of sugarcane (Saccharum sp.) and as a hazard to the environment in Mauritius was not known with certainty. A lysimeter study was therefore initiated to investigate leaching of N from soils planted with hybrid sugarcane and fertilized with either 15N‐labeled (NH4)2SO4 or NaNO3 at the rate of 100 kg N/ha. The results obtained showed that the amount of N leached by any one rainfall of sufficient magnitude to give rise to percolates depended more upon the duration and intensity of the drying step preceeding the rainfall than on the leachate volume. In consequence, N leached from any one soil by an outburst of rain was greater at the drier site (Reduit, 1550 mm rain/yr) than at the wet site (Belle Rive, 3700 mm rain/yr). However, the cumulative N loss over 1 yr was not invariably higher at Reduit than at Belle Rive because frequent though shorter and less intense drying and wetting cycles may be cumulatively just as effective in mobilizing soil N than the less frequent but longer and more intense drying at Reduit. In addition, at both sites more N was leached from the soil with a higher organic matter content.

Though the soils were able to retain NO3− by adsorption, the mobility of NO3− in the soils used was primarily reduced by biological immobilization. As a result, in spite of an annual rainfall exceeding 3000 mm at Belle Rive, N leaching was not more extensive than that reported for soils of the temperate regions. Instead, cations such as K+ and Ca2+ were more readily leached than N. This draws attention to the fact that the need for management practices to attenuate leaching losses of cations from soils located in a climatic environment similar to that of Mauritius may be more acute than the need for measures to minimize N leaching.
Site Relations of Slash Pine on Dredge Mine Spoils
Authors: Darfus G. H. , Fisher R. F.
Published: July 2010

Dredge mining for heavy minerals is carried out on large areas of Spodosol soils in the Georgia‐Florida coastal plain. Attempts to return these areas to productive slash pine (Pinus elliottii Engelm. var. elliotii) forests have usually failed. This study was conducted to determine if changes in soil moisture regime or extremely low nutrient availability induced by the mining operation were the causes of such failure. Nutrient contents of the mined soils were low, but this did not appear to be the major cause of poor tree growth. Changes in topography and the removal of organic and sesquioxide coatings from the thick spodic horizon caused the mined soils' moisture regimes to be very different from those occurring in the coarse sandy soils prior to mining. Before mining, the soils were fairly uniform, somewhat poorly drained Spodosols. After mining, the soils ranged from Typic to Aquic Quartzipsamments, and only a small proportion of the area retained a moisture regime suitable for vigorous slash pine growth. Plantation failure on these sites could have been mitigated by grading the spoils to nearly level contours and increasing the organic matter content through additions of waste humate from the mining process or sewage sludge, or by planting a variety of tree species onto the various microsites present in the mined landscape.
Use of Peat for On‐Site Wastewater Treatment: I. Laboratory Evaluation
Authors: Rock C. A. , Brooks J. L. , Bradeen S. A. , Struchtemeyer R. A.
Published: July 2010

Peat has been found to be an effective medium for the treatment of municipal and industrial wastewaters. Recent research has indicated that a peat filter can be utilized in the treatment of septic tank effluent (STE). Laboratory columns were used to determine the treatment capacity of sphagnum (Sphagnum spp.) peat at varying hydraulic and organic loadings.

Thirty centimeters of peat compacted to a density of 0.12 Mg/m3 was found sufficient to treat STE at a hydraulic loading of 8.1 cm/d and an organic loading of 20.2 kg BOD5/1000 m2 per day (BOD5 = 5‐day biochemical oxygen demand). The BOD reduction exceeded 95% and suspended solids 90%. Chemical oxygen demand (COD) reduction was only 80% as the effluent COD exceeded 100 mg/L. The relatively high COD was attributed to the organic matter leached from the peat itself. This was reflected in a light yellow color and lowered pH in the effluent. The effect seemed to be temporary in nature and improved COD, color, and pH values were obtained with time. Excellent fecal coliform reduction was obtained, suggesting that a separate disinfection operation may not be necessary.

Nutrient removal under aerobic conditions revealed < 10% P and N removal; however, nitrification was nearly complete. Significant denitrification was promoted under anaerobic conditions and a 62% reduction in total N was observed.

Specifications for a full‐scale filter include a hydraulic loading of 4.1 cm/d for a typical strength STE (10 kg BOD5/1000 m2 per day) as 8.1 cm/d proved to be excessive at low temperature (5°C). The filter should have a minimum of 30 cm of lightly compacted peat (0.10–0.12 Mg/m3) below the distribution pipes. These recommended design criteria result in a much smaller filter than previously tested.
Water Quality of Irrigation and Surface Return Flows from Flood‐Irrigated Pasture and Alfalfa Hay
Authors: Miller W. W. , Guitjens J. C. , Mahannah C. N.
Published: July 2010

Pollutants from agricultural irrigation practices continue to require empirical definition. This paper reports results from a 3‐yr investigation of pollutants and pollutant loads carried in irrigation and surface return flows from grass pasture (Bromusinermis Leyss, Dactylis glomerata L., Poa pratensis L., Festuca arundinacea Schrib.) and alfalfa hay lands (Medicago sativa L.) to adjacent receiving waters. Irrigation and surface return flows were metered and the volume of infiltrated water determined at four sites during three irrigation seasons. Concentrations of total dissolved solids (TDS), 5‐day biochemical oxygen demand (BOD5), nitrate‐N (NO3−‐N), total N (TN), phosphate‐P (ortho PO43−‐P), and total P (TP) were combined with flow volumes to compute changes in surface loading per individual irrigation and cumulative throughout the irrigation season. Of those parameters studied, BOD5 and P (PO43−‐P, TP) were found to have a net loss from the fields via surface return flow. Statistical relationships among the water quality parameters varied seasonally. Differences were attributed to seasonal changes in irrigation water supply and availability. Levels of constituent contributions to surface runoff appeared to be more related to site characteristics, water management practice, and hydrologic variation than to the presence or absence of grazing animals. Future efforts in water quality management and control should be directed towards quantifying the relationship between water quality as affected by specific management activities, followed by appropriate economic impact assessment of the control measure effects on agricultural productivity.
Adsorption of Curium‐244: Effects of Dissolved Organics and Sediment Extractions
Authors: Sibley Thomas H. , Alberts James J.
Published: July 2010

Adsorption of 244Cm, a transuranic isotope that absorbs strongly to suspended sediments, was measured on untreated and extracted sediments in filtered and ultrafiltered water. Partition coefficients (Kd) ranged from 7 × 103 to 5 × 105. The most important observations concern the role of dissolved and particulate organic matter. Ultrafiltration of water to remove dissolved organic compounds significantly reduced the concentration of soluble Cm and increased Kd for all types of sediments. Extraction of sediments with NaOH to remove humic and fulvic acids also increased Kd values. This may result because previously blocked adsorption sites are available for Cm adsorption or because particulate organics in unextracted sediments are solubilized during the experiments. Removal of hydrous oxides from sediments by extraction with sodium citrate/sodium dithionate or hydroxylamine‐hydrochloride did not produce consistent effects. It is suggested that hydrous oxides may be important for long‐term sediment‐water partitioning of Cm, but the initial adsorption is determined by interactions with dissolved and particulate organic matter.
Behavior Assessment Model for Trace Organics in Soil: III. Application of Screening Model
Authors: Jury W. A. , Spencer W. F. , Farmer W. J.
Published: July 2010

The soil chemical screening model developed in Jury et al. (1983) is applied to a set of 35 chemicals for which benchmark properties (organic C partition coefficient, vapor pressure, solubility, half‐life) have been obtained. Environmental screening tests are conducted on the chemicals to de{ermine their relative convective mobility, diffusive mobility, volatility, and persistence with the results presented in a series of classifications rating the susceptibility of the chemical to a given loss pathway.

The convective mobility tests estimate the time required for a pulse of chemical to travel a distance of 10 cm through an ideal soil of uniform water content and organic C content while being subjected to a water application rate of 1 cm/day. The diffusive mobility tests determine the time required for a chemical to diffuse 10 cm through the same ideal soil. In the volatilization screening tests, each chemical is applied at a uniform concentration of 1 kg/ha to a standard depth in the soil with uniform properties and is allowed to volatilize through a stagnant air boundary layer during a specified time period in the presence or absence of water evaporation. The resulting volatilization fluxes and cumulative losses for a standard time period are used to categorize the relative susceptibility of the chemical to loss to the atmosphere. The persistence tests are used to determine the amount of chemical left after a specified time period when it is free not only to degrade but also to volatilize.
Behavior Assessment Model for Trace Organics in Soil: IV. Review of Experimental Evidence
Authors: Jury W. A. , Spencer W. F. , Farmer W. J.
Published: July 2010

Experimental evidence supporting the environmental screening model of Jury et al. (1983) is reviewed and discussed. For several laboratory studies of volatilization, initial and boundary conditions matched those used in our model and simulations were run. In all cases, good agreement was found between predicted and measured volatilization losses, with and without accompanying water evaporation. When five chemicals of widely differing volatility were exposed to identical experimental conditions, the model correctly predicted the relative loss behavior observed.

The convective mobility predictions of the model were shown to be consistent with several laboratory studies of compound leaching, as long as the water flow rate was slow enough (< 0.01 cm/s) to ensure equilibrium between the solution and adsorbed phases.

The Millington and Quirk tortuosity model used in our representation of the soil diffusion coefficient was found to give a good prediction of the water content dependence of the effective diffusion coefficient observed in several studies. The thickness of the stagnant boundary layer predicted from our similarity assumption was shown to be consistent with the apparent thickness inferred from several laboratory and field measurements of volatilization.
Effects of Wastewater Disposal on Growth Rates of Cypress Trees
Authors: Lemlich Sandra K. , Ewel Katherine Carter
Published: July 2010

A swamp in north Florida received raw sewage from 1914 to 1951, primary wastewater from 1952 to 1972, and secondary wastewater from 1973 through the present. A study conducted at this swamp to determine long‐term impacts of wastewater discharge included an analysis of the growth rates of surviving trees. Increment cores were taken from cypress trees [Taxodium distichum var. nutans (Ait.) Sweet] in this swamp and from a nearby undisturbed cypress swamp. Annual basal area increments were calculated for 75 yr to determine whether the growth rates differed during the various discharge periods relative to growth rates at the control swamp. Disposal of untreated or primary wastewater was detrimental to tree growth. Secondarily treated wastewater enhanced tree productivity, and growth rates during this period returned to levels that were similar to control growth rates. Cypress swamps should not be used for disposal of raw sewage or primary wastewater because of the negative impact on the trees, but trees that survive such conditions are apparently able to recover normal growth rates when the wastewater is upgraded.
Identification of Injury Resulting From Atmospheric Pollutants Using Reflectance Measurements
Authors: Schutt J. B. , Rowland Randy A. , Heggestad Howard E.
Published: July 2010

Tomatoes (Lycopersicon esculentum Mill. cv. Jet Star) were grown under field conditions in open‐top chambers at Beltsville, MD. Sets of chambers circulating carbon‐filtered air to remove the O3 and non‐filtered air with and without an admixture of SO2 at 1256 µg/m3 comprised the treatments. Mean reflectances and their corresponding standard deviations were calculated at 475, 550, 660, and 725 nm for leaflets selected from all chambers. Results of these calculations showed that the reflectance at 550 nm was the most responsive to treatment, while 725 nm showed intermediate response. Since both 475 and 660 nm were shown to be treatment insensitive, each was selected as a basis from which a threshold reflectance level could be established for the assessment of incipient injury. The data revealed that the effects of pollutants on leaflets could be assessed by differencing one of the treatment‐sensitive wavelengths, 550 or 725 nm, with respect to one of the treatment‐insensitive wavelengths, 475 or 660 nm, and comparing the resulting differences with the appropriate threshold reflectance viz: (R550‐Ri)j > (< R550‐Ri >)c + 2δic, where i = 475 or 660 nm, j refers to treatments, and (< R550‐Ri >)c and δic refer to the average reflectance at 550 nm relative to the reference wavelength i for the controls and standard deviation at the reference wavelength, respectively. The standard deviation is positive because in no instance was (R550‐Ri)j less than (< R550‐Ri >)c. In combination, these factors functioned as a threshold reflectance. For i = 475 nm, the criterion was more sensitive to abaxial injury, whereas for i = 660 nm, it was found more effective in predicting adaxial effects. To evaluate the criterion, percentages of injured leaves were compared with fruit yield (weight) information. Using 660 nm for the reference wavelength, the percentages of injured leaflets were 38.4, 32.0, and 30.9% for O3 + SO2), O3, and SO2, while the respective yields were 68, 82, and 84% of the control. Using 475 nm, the values for the same sequence were 57.7, 55.1, and 41.3%, demonstrating that both reference wavelengths correctly ordered injured leaflets with respect to yield data.
Causes of Acidification of Four Streams on Laurel Hill in Southwestern Pennsylvania
Authors: Sharpe William E. , De Walle David R. , Leibfried Robert T. , Dinicola Richard S. , Kimmel William G. , Sherwin Lysle S.
Published: July 2010

Atmospheric deposition, soils developed from bedrock, a natural bog, gas wells, and a ski area were all investigated as possible sources of water quality degradation for four streams on Laurel Hill in southwestern Pennsylvania where fish kills have been reported since 1960. An intensive study of the chemistry of atmospheric deposition, soil leachate, and stream water and fish populations was conducted on these basins during 1980–1981 with emphasis on dormant season periods with runoff from snowmelt and rain. Although bedrock geology was found to control the natural buffering capacity of these streams, only acid precipitation could be linked to sharp drops in pH and increases in total Al concentrations observed during stormflows in the poorly buffered streams. Three poorly buffered streams exhibited drops to pH 4.4 to 4.5 and increases in total Al concentrations up to 1.5 mg/L during observed peak flows. Mineral soil leachate from the three major soil series on the basins during this time exhibited a low pH of 4.3 and mean total Al concentrations of 3.6 mg/L, indicating stream response during storms was closely linked to chemistry of soil leachate. Poorly buffered streams did not support reproducing populations of trout (Salmonidae sp.) or other fishes. In contrast, one well‐buffered stream (20 mg/L CaCO3) exhibited drops to pH 5.5 during peak flow and supported reproducing trout and sculpin (Cottus bairdi) populations. The acidification of the four streams studied was attributed to atmospheric deposition.
Heavy Metal Contents of Sludge‐Treated Soils as Determined by Three Extraction Procedures
Authors: Cao Hong‐Fa , Chang A. C. , Page A. L.
Published: July 2010

The extraction efficiency of three soil metal extraction procedures (4M HNO3 extraction, HClO4 digestion, and HF decomposition) were compared by determining Cd, Cr, Cu, Ni, Pb, and Zn contents of two sewage sludge‐treated soils. In soils not treated with sludges, approximately 50 and 75% of total metals (HF‐decomposed) were recovered by 4M HNO3 extraction and HClO4 digestion, respectively. For sludge‐treated soils, between 70 and 80% of soil metals were recovered by 4M HNO3 extraction. The increase in extraction efficiency indicated that sludge‐borne heavy metals in soils were more extractable with 4M HNO3 than metals indigenous to soils. Amounts of Cd, Cr, Cu, and Zn recovered from sludge‐treated soils by HClO4 were not significantly different from those recovered by HF decomposition. Recoveries of Ni and Pb by HClO4 digestion, however, were less complete. It appeared that sludge‐borne Ni and Pb were either associated with silicate minerals or converted into silicate‐containing solid phase minerals after land application.
Sludge Application to Land Compared with a Pasture and a Hayfield: Reduction of Biological Health Hazard Over Time
Authors: Wallis P. M. , Lehmann D. L. , Mac Millan D. A. , Buchanan‐Mappin J. M.
Published: July 2010

Economic and environmental pressures favor the disposal of sewage sludge on agricultural land. In order to assess this hazard, this study investigated the occurrence and survival of primary and secondary bacterial pathogens, parasite eggs, and enteroviruses in sludge injected by machine into a fallow field, sludge spread on a grass plot (Poa spp. and Fescue spp.), a pasture grazed by cows (Bos taurus), and on soil taken from a control hayfield (dominated by Bromus spp.). It was assumed that the unsludged hayfield represented an acceptable level of “risk.”

The sludged plots compared favorably with the control hayfield with respect to the occurrence and survival of nematode parasites, enteroviruses, and primary bacterial pathogens. Secondary bacterial pathogens persisted on all fields throughout the study, but levels declined more slowly on the sludged grass plot than the injected sludge field, the pasture, or the control hayfield. Despite the persistence of secondary pathogens (which are normally present on grazed fields), the health hazards to humans and animals were judged to be comparable to those on a hayfield and a pasture that had not been sludged.
Research on the Response of Vegetation to Elevated Atmospheric Carbon Dioxide
Authors: Dahlman Roger C. , Strain Boyd R. , Rogers Hugo H.
Published: July 2010

The global rise in atmospheric CO2 is an established phenomenon. Irrespective of whether a CO2‐induced climate change occurs, it is abundantly clear that the earth's mantle of vegetation will be directly affected by increased CO2 levels. Carbon dioxide is essential for plant growth (plants obtain C from CO2 in the atmosphere); a higher level of CO2 will increase the rate of photosynthesis. Quantitative information on the CO2‐induced growth response for field situations is needed for assessments of (i) possible benefits to agriculture, (ii) the amount of fossil C that can be sequestered by CO2‐accelerated growth of the biosphere, and (iii) unknown or unidentified effects of CO2 on the physiology, structure, and function of plants and ecosystems. Along with knowledge of CO2 effects on climate and other factors, information on direct plant effects will be used in comprehensive evaluations of policy options related to increasing atmospheric CO2. Herein, a discussion of the plan by the U.S. Department of Energy (DOE) to address the CO2 problem is presented along with research results from two programs, one agricultural and the other ecological.
Swine Lagoon Effluent Applied to ‘Coastal’ Bermudagrass: III. Irrigation and Rainfall Runoff
Authors: Westerman P. W. , Overcash M. R. , Evans R. O. , King L. D. , Burns J. C. , Cummings G. A.
Published: July 2010

In moisture excess regions, irrigation of lagoon effluent to land is generally required to prevent water pollution from lagoon overflow. However, the land area receiving lagoon effluent then becomes a potential nonpoint source of pollution, especially if effluent is applied at high rates.

The quantity and quality of rainfall runoff were determined for 6 yr from plots of ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] on typical Coastal Plains soils that received weekly irrigations of swine (Sus scrofa domesticus) lagoon effluent during the growing season. Three application rates supplied an average of 335, 670, and 1340 kg N ha−1 yr−1; 90, 180, and 360 kg P ha−1 yr−1; and 200, 400, and 800 kg Cl− ha−1 yr−1.

The soil‐crop characteristics promoted high infiltration of rainfall and the plots were not irrigated during the nongrowing season, when runoff is usually highest. Thus, both runoff volume and nutrient mass transport were low, but nutrient concentrations were relatively high compared with typical concentrations in cropland runoff. Average annual arithmetic mean concentrations ranged from 7 to 13 mg L−1 for total N and from 3 to 6 mg L−1 for total P for the three treatments. Treatment differences were usually significant for the high‐rate treatment, but not significant between the low‐ and medium‐rate treatments. For this soil‐crop system, NO3−‐N movement to groundwater and P accumulation in the soil for the high‐ and medium‐rate treatments would likely be of more concern than the pollution of rainfall runoff.
Nodule Activity in Soybean Cultivars Exposed to Ozone and Sulfur Dioxide
Authors: Jones A. W. , Mulchi C. L. , Kenworthy W. J.
Published: July 2010

In an effort to obtain a greater understanding of the mechanisms of action for air pollutants on yield‐limiting processes in crop plants, studies were conducted in the field and greenhouse in 1979 to investigate the effects of O3 and SO2 exposures on nodule activities in roots and chlorophylls a and b contents in leaves of soybeans [Glycine max (L.) Merr.]. Six cultivars of soybeans were exposed 4 h d−1 for 5 successive days during flowering and pod development to the combination of 6.7 µmol m−3 O3 and 11.1 µmol m−3 SO2 in activated charcoal‐filtered air. Acetylene reduction procedures were used to assay nodule activities.

Significant differences (P < 0.1) were observed in total nodule activity (TNA) per plant for treatments and cultivars in combined analysis of variance (ANOVAs) for two greenhouse studies and two exposure dates in the field; however, treatment × cultivar interactions were nonsignificant in all cases. Compared with filtered air controls, the air pollution treatment reduced TNA by an average of 16.4 and 27.4% in the greenhouse and field studies, respectively. Specific nodule activities (SNA) were unaffected by the treatments in both studies. In the greenhouse studies, the O4 and SO2 treatment lowered the chlorophyll a content by 14.1%, but no significant differences were observed in the field study. Chlorophyll b contents were unaffected by treatments in both investigations. In these studies, the sensitivity of changes in chlorophyll contents in soybean leaves following exposures to O3 and SO2 at concentrations found in the atmosphere were found to be too low to be of practical value for screening plants for tolerance to air pollutants.
Effect of Acid Precipitation on Soil Microbial Activity: II. Field Studies
Authors: Bitton G. , Volk B. G. , Graetz D. A. , Bossart J. M. , Boylan R. A. , Byers G. E.
Published: July 2010

The effects of acid precipitation on selected microbiological processes were investigated under field conditions. The study site, near Lake McCloud, FL, was composed of three transects, each including three plots. Each transect was spray‐irrigated with lake water at various levels of acidity. Acid rain did not significantly reduce dehydrogenase, phosphatase, or urease activity; protease activity was decreased. Similarly, soil respiration was not altered by acid rain of pH 3.7 or 3.0. It was, however, observed that acid rain significantly reduced nitrification at both pH levels. Laboratory and field data were compared and discussed.
Butanol Degradation and Volatilization in Soils Amended with Spent Acid or Sulfuric Acid
Authors: Fairbanks B. C. , Schmidt N. E. , O'Connor G. A.
Published: July 2010

Butanol persistence may be an important consideration in determining the phytotoxic effects of alkylation spent acid added to soils. The degradation and volatilization of n(1‐14C)butanol were thus monitored in two calcareous soils from New Mexico amended or unamended with spent or reagent grade sulfuric acids. Degradation of butanol to CO2 was rapid and was the primary mechanism of loss from these soils. After 20 d, 14CO2 evolution averaged 58 and 51% of the added 14C for Glendale clay (Typic Torrifluvents) and Lea sandy loam (Petrocalcic Paleustolls), respectively; a majority of this loss occurred within 2 d. Acid type (spent or reagent grade) did not affect degradation, but 14CO2 production increased with acid rate. Volatilization was essentially complete within 1 d and averaged 8 and 16% of the added 14C for the Glendale clay and Lea sandy loam soils, respectively. Acid rate, but not acid type, affected volatilization loss. The summation of degradation and volatilization losses was similar for both soils and averaged 67% after 20 d, a majority of which was lost within 2 d.
Rates of Iron Sulfide Oxidation in Coal Spoil Suspensions
Authors: Evangelou V. P. , Grove J. H. , Rawlings F. D.
Published: July 2010

Rates of pyritic coal spoil oxidation were studied in water suspensions of each of two particle‐size fractions (< 0.5 mm and 0.5–2 mm). The treatments on each of the size fractions included liming with reagent grade CaCO3 at rates of 0, 14.4, and 28.8 g kg−1. In another treatment, toluene was added to unlimed suspensions to inhibit microbial growth.

The greatest rate of salt formation (taken as a measure of pyrite oxidation) was associated with the larger size fraction. Toluene suppressed the oxidation‐dissolution rate, suggesting a microbial role in pyrite oxidation in these systems. The application of CaCO3 at 14.4 g kg−1 spoil to the 0.5‐ to 2.0‐mm size fraction enhanced the oxidation‐dissolution process during the initial phase of the reaction (0–100 min). When the larger size fraction was amended with CaCO3 at a rate of 28.8 g kg−1, three rates of oxidation‐dissolution were apparent. The first rate was attributed to dissolution of indigenous sulfate salts. The second rate was attributed to oxidation of a more reactive pyrite fraction than that described by the third rate (slowest rate). This last rate was attributed to a nonmicrobial oxidation pathway due to the higher pH values observed in the suspension.