bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogen Ion Concentration and Alkalinity of Reservoir Water in the Sierra Nevada, California, and Correlations with Air Pollutants
Authors: McColl J. G.
Published: July 2010

Pardee reservoir supplies water for the east San Francisco Bay Area from a large forested drainage basin located in the Sierra Nevada foothills, extending east to the crest of the mountain range. Analyses of weekly data of reservoir discharge water indicate that [H+] has been increasing (1954–1985 data) and alkalinity decreasing (1944–1985 data). Hydrogen ion concentration and alkalinity of reservoir water are correlated with NOx (and SO2 to a lesser extent) emissions from the San Francisco Bay Area. Emissions of NOx are about four times greater than those of SO2. A lag‐time of 3 to 4 yr improves the correlations, especially those of SO2. Greatest increases in [H+] occur in spring when the snowpack is melting. In the 1950s, spring melt had a dilution effect on [H+], but now [H+] increases during spring melt. The following is an explanation for the seasonal variations observed: Atmospheric NOx and SO2 appear to have their greatest effect on [H+] of water when there is little contact of runoff with soils and rocks. There is no correlation between acidity and alkalinity during the winter when water penetrates the soil profile, resulting in proton exchange with soil “base cations.” During summer, when runoff is minimal, other processes within the reservoir appear to control [H+] and alkalinity. Alternative hypotheses are discussed, which may help explain the observed trends in [H+] and alkalinity over seasons and years. These hypotheses largely involve processes within the reservoir, but without historical data their importance remains unclear.
Agricultural Impacts of Coal Mine Subsidence: Evaluation of Three Assay Methods
Authors: Darmody R. G. , Steiner J. S. , Jansen I. J. , Carmer S. G.
Published: July 2010

A microcomputer and spread sheet program were used to store and analyze data from a collection of maps and aerial photographs in a research project concerning the agricultural impacts of underground coal mine‐induced subsidence. Topographic, soils, and mine maps along with pre‐mine archival photos and 1:12 000 aerial photos flown over the 3 yr of the project were used. The research area included about 18 000 ha of predominantly agricultural land. The overall objective of the research project was to assess the damage to agricultural production caused by underground coal mine subsidence. The work reported here details the development and evaluation of the method used to meet the overall objective. A 64‐point grid overlay adjusted to fit a township section on each of the images was used to mark individual sampling points. The categories of information recorded at each grid point were: mine name, township, section, grid point, land use, subsidence impact, mine type, mine panel orientation to slope, soil type, and soil slope. Each category had several classes to give a total of 196 possible classes for each of 3 yr of the study. These classes were visualiy assigned under each grid point on an image and then recorded on a 640 Kbyte microcomputer spread sheet. It was then possible to calculate each class area and class combination interactions over the time of the study. The validity of the approach was confirmed by two independent checks and by corn (Zea mays L.) yields determined at selected sites. The method is inexpensive and applicable to other similar land use or environmental studies.
Aluminum and Iron Equilibria in Soil Solutions and Surface Waters of Acid Mine Watersheds
Authors: Karathanasis A. D. , Evangelou V. P. , Thompson Y. L.
Published: July 2010

The composition of soil solutions and surface waters emanating from unreclaimed or partially reclaimed stripmined watersheds with low buffering capacity in Kentucky were compared with soil solution compositions of unaffected strata in the watershed. The data suggest that almost 20 yr after mining, most soil solutions and surface waters of the disturbed areas still contain high levels of dissolved Al, controlled primarily by the solubilities of a jurbanite‐like mineral (upper limit) and alunite (lower limit). Soluble Al in solutions of undisturbed areas was consistent with the solubility of kaolinite or gibbsite. The absence of jurbanite x‐ray diffraction peaks suggested the presence of an amorphous or a mineral stoichiometrically similar to jurbanite. Despite greater contact times of soil solutions with the soil compared to surface waters, their compositional differences were insignificant. The control of soluble Al by basic aluminum sulfate minerals was not affected by the variable mineralogical and textural composition of soil and geologic strata in the watershed. Apparently, this is the result of low buffering capacity. At pH < 4, pH and sulfate activities can be used to accurately predict the levels of soluble Al3+ in surface and groundwaters of the watersheds. Similar predictions from pH and SO2−4 activities can also be made for dissolved Fe3+ levels, supporting the stoichiometry but a much higher solubility than that of jarosite.
Relative Concentrations of Cadmium and Zinc in Tissue of Selected Food Plants Grown on Sludge‐Treated Soils
Authors: Kim S. J. , Chang A. C. , Page A. L. , Warneke J. E.
Published: July 2010

Twelve selected food plants were grown in greenhouse pots to determine the relative concentration of Cd and Zn in the plants grown in sludge‐treated soils. The relative concentration of the metal was calculated as the quotient of the metal content in a plant and that in Swiss chard [Beta vulgaris subsp. cicla (L.) Koch] grown under the same soil conditions. The relative concentrations of Cd and Zn of food plants grown in several sludge‐treated soils were significantly different (p < 0.01), but the relative concentrations of these plants in one soil has the statistical characteristics (e.g., range, mean, median, coefficient of variation, etc.) as those in another soil.
Soil Microbial Populations and Activities under Conventional and Organic Management
Authors: Fraser D. G. , Doran J. W. , Sahs W. W. , Lesoing G. W.
Published: July 2010

Evaluation of microbial populations and activities, and their relationship to N cycling in soils under organic and conventional farm management was conducted in eastern Nebraska in 1981 and 1982, on an experiment initiated in 1975. The experimental treatments consisted of 3 × 4 factorial with three management systems (organic, fertilizer only, and fertilizer plus herbicide) for a 4‐yr grain/legume crop rotation plus one treatment of continuous corn (Zea mays L.) receiving fertilizer, herbicide, and insecticide (including one subplot without insecticide). Soil physical, chemical, and microbiological characterizations were made at soil depth intervals of 0 to 7.5, 7.5 to 15, and 15 to 30 cm. Soil chemical properties were significantly influenced by chemical management, primarily the application of beef (Bos taurus) feedlot manure in the organic management system. Total organic C, Kjeldahl N, and potentially mineralizable N in manure‐amended surface soils (0–7.5 cm) were 22 to 40% greater than nonmanured soils receiving fertilizer and/or herbicide. Soluble P levels were eightfold greater in manure‐amended surface soils, and soil nitrate levels after harvest in 1981 were two‐ to threefold greater to a depth of 30 cm than nonmanured chemical treatments. Soil microbial biomass, bacterial and fungal counts, dehydrogenase activity, and CO2 evolution were greater in soils planted to oat/clover (Avena sativa L./Trifolium pratense L. + Melilotus officinalis Lam.) and treatments receiving manure. Increases in microbial populations and their activities paralleled increases in soil organic C content, Kjeldahl N, and water‐filled pore space. Differences in N2 fixation and denitrification between crops and management systems were minimal—possibly resulting from suboptimal water availability at midseason sampling. No significant differences were found in measured soil physical, chemical, or biological properties due to herbicide or insecticide at field application rates.
Growth and Nutrient Content of Red Spruce Seedlings in Soil Amended with Aluminum
Authors: Ohno Tsutomu , Sucoff Edward I. , Erich M. Susan , Bloom Paul R. , Buschena Cynthia A. , Dixon Robert K.
Published: July 2010

Aluminum toxicity may be a factor linking acid deposition to forest decline. Acid precipitation may lower soil pH, which would raise the level of phytotoxic forms of Al in soil solution. A greenhouse study was conducted to examine the effects of soil Al on the growth and nutrient composition of red spruce (Picea rubens Sarg.). A Becket series forest soil (Typic Fragiorthod) was amended with AlCl3 to give a range of saturated paste extract Al concentrations from 37 to 537 µmol L−1 at harvest. Bare‐rooted seedlings were transplanted into pots and grown for 52 d. Biomass of needles, primary roots, and lateral roots were not significantly decreased by soil Al levels. The biomass of needles were negatively correlated with the concentration of Al in the needles. All seedlings were P‐deficient, which may account for the lack of response to soil Al levels. The concentration of Al in seedling needles increased significantly with increasing soil Al levels, but not in the primary or lateral roots. The concentration of Mn in seedling needles, primary roots, and lateral roots decreased with higher concentrations of Al in the soil. The concentrations of N, P, K, Ca, Mg, Fe, Zn, Cu, and B in the needles were not affected by soil Al. However, the Mg, Ca, and B concentrations in both primary and lateral roots were significantly lower with increasing levels of soil Al. Increasing soil Al levels resulted in lower nitrification rates in the soils. The addition of Al significantly reduced colonies of bacteria relative to the control soil. However, fungi/actinomycetes colonies were not significantly reduced by soil Al.
Mobility and Persistence of Metolachlor and Aldicarb in Field Lysimeters
Authors: Bowman B. T.
Published: July 2010

The mobility and persistence of metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1‐methylethyl)acetamide], a herbicide, and aldicarb [2‐methyl‐2‐(methylthio)propanaldehyde O‐(methylcarbamoyl) oxime], an insecticide, were studied using field lysimeters containing 15 cm (diam.) by 70 cm (length) cores of Plainfield sand (mixed, mesic Typic Udipsamments). One‐half of the cores received only rainfall, while the remainder received rainfall plus simulated 50.8‐mm rainfalls on the second and eighth days after treatment, followed by simulated irrigation for the duration of the study. Metolachlor exhibited limited mobility, except in the supplementary watering treatment, in which there was rapid transport of some herbicide 40 cm down the core, with accompanying traces in the effluent. Metolachlor half‐life was in the 3‐ to 4‐wk range. Aldicarb rapidly converted to its sulfoxide [2‐methyl‐2‐(methylsulfinyl)propanal O‐(methylamino)carbonyl oxime] and sulfone [2‐methyl‐2‐(methylsulfonyl)propanal O‐(methylamino)carbonyl oxime] (50% in 3–5 d). Under normal rainfall, about 9% of the applied aldicarb leached out of the soil cores as sulfoxide or sulfone. In cores receiving supplementary watering, up to 64% of applied aldicarb appeared in the effluent principally as sulfoxide or sulfone.
Effects of Chronic Exposure to Simulated Power Plant Emissions and Ozone in Soybean Production
Authors: Jones Herbert C. , Noggle J. C. , McDuffie Charlie
Published: July 2010

Acute SO2 effects on vegetation are less likely because large point sources comply with ambient air quality standards and emission limits. The remaining concern is for direct effects of SO2, which might occur from exposure to intermittent, subacute dosages. Limited data exist for assessing chronic effects because experimental exposure regimes used in most effect studies on soybean [Glycine max. (L.) Merr.] are from field and laboratory exposure regimes consisting of SO2, NO2, and O3 dosages with a high degree of uncertainty. Chronic exposure of ‘Essex’ soybean to 0.06 µL L−1 (0.06 ppm) O3 for 8 h d−1, 5 d wK+−1, for 18 wk in the greenhouse caused a 34% reduction in yield compared to charcoal‐filtered air. Sulfur dioxide in combination with O3 and NO2 caused no additional reduction in yield, but lower dosages of SO2 increased yields compared to the O3 treatment, apparently by retarding O3‐induced premature senescence. Emissions from a power plant had no adverse effect on yield on the cultivar Essex during a 3‐yr field study (1981–1983).
Form and Availability of Copper and Zinc following Long‐Term Copper Sulfate and Zinc Sulfate Applications
Authors: Payne G. G. , Martens D. C. , Winarko C. , Perera N. F.
Published: July 2010

High levels of Cu and Zn application to agricultural land poses potential environmental hazards due to reduced plant growth and accumulations of undesirable levels of Cu and Zn in the food chain. The levels of Cu and Zn that can be safely added to cropland have yet to be established. This study was conducted on a Davidson silty clay (Rhodic Paleudult) to determine the response of corn (Zea mays L.) to the cumulative application of up to 415 kg Cu and 897 kg Zn ha−1 as CuSO4 and ZnSO4, respectively, over the 20‐yr period from 1967 through 1986. Neither corn grain nor silage yields were affected by the metal additions, even though the cumulative added amounts of Cu and Zn greatly exceeded the maximum allowed Cu and Zn loading rates (i.e., 250 kg Cu and 560 kg Zn ha−1) for this soil. Over the period from 1984 through 1986, Cu concentrations in leaf and grain tissue were generally unaffected by metal applications, whereas Zn concentration in ear leaves increased linearly with the cumulative level of applied Zn. Zinc concentration in corn grain was increased only by the highest rate of Zn application. Copper and Zn concentrations in the corn leaves and grain were within normal ranges for all treatments. Levels of DTPA‐extractable Cu and Zn in the Ap horizon sampled annually from 1984 through 1985 increased linearly with the amount of metals applied (r2 = 0.97 and 0.98, α = 0.001, for Cu and Zn, respectively). Extractable Cu was also influenced by Zn applications with a larger amount of extractable Cu being present when both Cu and Zn were added compared to when only Cu was applied. Analysis of subsoil samples indicated limited downward movement of Cu and Zn. Sequential extraction data revealed that the applied Cu and Zn was distributed among both potentially plant‐available (exchangeable, specifically adsorbed, and organically bound) and plant‐unavailable (oxide associated) fractions. The results of this study indicate that application of 135 kg Cu and 337 kg Zn ha−1 in excess of the limits set forth by USEPA guidelines was not detrimental to corn production on the Davidson soil with a pH > 6.5. The reasons for the lack of phytotoxicity of the metals include the relatively high soil pH maintained at the site, which limits the availability and the conversion of the applied Cu and Zn to plant‐unavailable forms over time.
Solubility Relationships of Zinc Associated with Acid Mine Drainage
Authors: Reddy K.J. , Sullivan Patrick J. , Yelton Jennifer L.
Published: July 2010

Acid mine drainage, produced from the oxidation of iron‐sulfides, often contains elevated levels of dissolved Zn. To predict environmental hazards, it is important to understand the solubility relationships of Zn associated with acid mine drainage. Two eastern oil shales were leached under aerobic unsaturated environments using the humidity cell method. This study used a New Albany Shale (unweathered, 4.6% pyrite) and a Chattanooga Shale (weathered, 1.5% pyrite). The leachates from the humidity cells were filtered, and the filtrates were analyzed for total concentrations of cations and anions. From the total concentrations, ion activities were calculated, after correcting for significant solution complexes and ion pairs. The results show that the pH of the leachates decreased due to oxidation of pyrite. Furthermore, oxidation of pyrite increased the solubility of Fe3+ and Zn2+ in leachates. Above pH 7.00, the Zn2+ activity was supported by Zn2SiO4 (willemite) in equilibrium with measured H4SiO04 activity. Below pH 5.00, Zn2+ activity for both shales appeared to be saturated by ZnFe2O4 (franklinite) in equilibrium with measured Fe3+ activity. The results in this study suggest that Zn2+ solubility in acid mine drainage, produced in an aerobic unsaturated environment, may be limited by ZnFe2O4 solid phase.
Solid State Cadmium‐113 Nuclear Magnetic Resonance Study of Cadmium Speciation in Environmentally Contaminated Sediments
Authors: Bank Shelton , Bank Janet F. , Marchetti Paul S. , Ellis Paul D.
Published: July 2010

An initial investigation used solid state 113Cd nuclear magnetic resonance (NMR) spectroscopy to analyze five soil samples taken from an environmental site that is heavily contaminated with Cd and other metals. The experiments performed used Bloch decays, cross polarization, and echo train pulse sequences. The signals were obtained by coaddition transients numbering from 1000 to 500 000. Not all of the Cd present was observed by the NMR experiments likely due to the presence of paramagnetic species as indicated by the magnetic susceptibilities of the samples. Four cadmium species are indicated: (1) the carbonate as the major component; (2) a carbonate‐like species but in a soil‐like matrix; (3) a mixed hydroxycarbonate species; and (4) a species similar to (3) but in a soil‐like environment. Dynamics (motion) is considered as a possibility for the larger linewidths of the species in the soil‐matrix.
Soil Loss Comparisons between Reclaimed Strip‐Mined and Undisturbed Grasslands in North Dakota
Authors: Schroeder S. A.
Published: July 2010

Minimizing erosion from reclaimed strip‐mined lands is one goal of successful reclamation. This study was conducted at two mining locations to determine reclamation effects on soil loss/runoff ratios (SLRO) and soil loss amounts from grasslands several years after revegetation as compared to undisturbed grasslands of the same soil series present before mining. Artificial rainfall applications were applied at 56 mm h−1 to replicated 1.8 by 4.9 m plots to simulate dry, wet, and very wet surface conditions. Slope gradient effects on SLRO or soil loss were not significant (P = 0.10) except on one reclaimed site. No definitive trends in the SLRO or soil loss amounts were observed due to slope gradient. Significant differences for SLRO and soil loss amounts were found at one location only between the reclaimed and undisturbed grasslands due to no measurable soil loss on the undisturbed site. Soil losses ranged from 0 to 0.48 Mg ha−1 for the reclaimed and 0 to 0.46 Mg ha−1 for the undisturbed grasslands for the three surface conditions. Estimated soil credibility factors for the Universal Soil Loss Equation showed no significant differences within locations when calculated from the nomograph, but one location showed significant differences when calculated from the actual field data. Agreement between the two estimates was close for two of the three reclaimed grasslands but not so for the other grasslands.
Natural Inactivation of Enteric Viruses in Seawater
Authors: Girones R. , Jofre J. , Bosch A.
Published: July 2010

abstract

The stability of viruses in marine water was evaluated. Poliovirus 1 was readily inactivated in seawater from five different sources. Moderately polluted water samples showed more antiviral activity than more heavily polluted or unpolluted samples. An antiviral activity coefficient (AVA) was calculated to express the level of antiviral activity in the test samples, demonstrating the occurrence of natural virus‐inactivating phenomena in all the marine samples but not in freshwater samples. The major virus‐inactivating agent(s) appeared to be of bacteriological nature on the basis of the physical size and the susceptibility of the antiviral activity to thermal and antibiotic treatments. In studies on comparative survival, poliovirus 1 showed faster decay rates than rotavirus SA11, coliphage f2, and bacteriophage B40‐8 under laboratory and field conditions. No differences among the other viral strains were observed. The validity of bacteriophages as surrogate indicators of viral pollutants in the marine environment is discussed.
Influence of Sterilization Methods on Selected Soil Microbiological, Physical, and Chemical Properties
Authors: Wolf D. C. , Dao T. H. , Scott H. D. , Lavy T. L.
Published: July 2010

Valid results from studies of adsorption of labile organic compounds in soil can be obtained only if microbial degradation of the compound is inhibited. This study investigated effectiveness of sterilization of three silt loams with dry heat, cobalt‐60 irradiation, propylene oxide, mercuric chloride, autoclaving, sodium azide, microwave, chloroform, and antibiotics. These treatments were begun after air‐dried, sieved soil was moistened to −30 kPa water potential and incubated for 48 h at 25 °C. Sterilization was effective and microorganisms were eliminated by cobalt‐60 irradiation, propylene oxide, mercuric chloride, and autoclaving 2 × or 3 × as evidenced by a lack of microbial growth on potato‐glucose agar, plate count agar, and nutrient broth. Soil physical and chemical properties were altered by most sterilization treatments. Measured surface areas of the three soils were significantly reduced by propylene oxide. Propylene oxide and sodium azide produced an average pH increase for the three soils of 0.7 and 0.3 units, respectively. All effective sterilization methods except mercuric chloride significantly increased extractable Mn levels in the three soils. None of the effective treatments significantly influenced cation exchange capacity or levels of extractable Ca, Mg, and K of the soils. Mercuric chloride resulted in effective sterilization with minimal changes in soil chemical and physical properties. Following proper safeguards, mercuric chloride could be used to prevent microbial degradation in studies to evaluate adsorption of labile organic chemicals by soil.
Sorption‐Desorption of Dicamba and 3,6‐Dichlorosalicylic Acid in Soils
Authors: Murray M. R. , Hall J. K.
Published: July 2010

Sorption‐desorption of the herbicide dicamba (3,6‐dichloro‐2‐methoxybenzoic acid) and its metabolite 3,6‐dichlorosalicylic acid (DCSA) was studied in soils using experimental conditions that modeled selected physical and chemical properties of soils. Changing the soil/solution ratio (1:1 and 1:10) and temperature (15, 25, and 35 °C) of the soil slurry had no significant effect on sorption of dicamba for the soils studied, except for the Elkton (Typic Ochraoquults) Ap where, at a 1:1 soil/solution ratio, Freundlich constants, Kf, of 0.08 and 0.07 were found at 15 and 25 °C, respectively. The DCSA sorbed to all five soils under all experimental conditions with Kf values ranging from 1.23 for the Evesboro soil (Typic Quartzipsamments) to 34.04 for the Hagerstown Bt soil (Typic Hapludalfs). Changing the soil/solution ratio from 1:1 to 1:10 did not significantly change the Kf, except for the Hagerstown Bt, where an increase in Kf value from 27.54 to 29.79 was obtained. Increasing temperature from 15 to 35 °C generally resulted in a decreased Kf value for DCSA. Both dicamba and DCSA showed increased sorption with decreasing equilibrium solution pH. The percent of sorbed DCSA that was desorbed after two washings with deionized water was 28.2% or less for these soils. Dicamba was readily desorbed (79.2%) after two washings from the Elkton soil. Dicamba showed increased sorption when the Hagerstown Ap was saturated with Fe3+, but did not show any response to Cu2+, Al3+, and Ca2+ saturations. The DCSA showed increased sorption to all four cation saturations. A complexation bonding mechanism between DCSA and polyvalent surface cations is proposed. For limed agricultural soils, dicamba would be highly mobile in both topsoil and subsoil matrices. Once dicamba degrades to DCSA, however, sorption can be expected to become significant. Under field conditions, DCSA sorption can be expected to increase with soil depth, especially where soil pH and temperature decrease and exposed surface metal groups increase.
Effects of Ozone or Sulfur Dioxide on Pitch Pine Seedlings
Authors: Scherzer Amy J. , McClenahen James R.
Published: July 2010

Pitch pine seedlings (Pinus rigida Mill.) were fumigated with O3 or SO2 to determine their effects on growth and symptom expression. Seedlings fumigated twice with 0.20 µL O3 L−1 for 4 hr at age 14 and 22 wk had significantly greater shoot weight than those fumigated with 0.30 µL O3 L1; 0, 0.08, 0.10, and 0.15 µL L1 were intermediate and not significantly different. Root starch content tended to decrease with increasing O3 with control seedlings being significantly higher than the 0.15, 0.20, and 0.30 µL O3 L−1 treatments. Root starch of seedlings treated with 0.20, 0.50, 0.60, 0.70, and 0.90 µL SO2 L−1 was significantly lower than the controls. Seedlings from six families fumigated for 5 wk starting at age 6 wk differed in direction and degree of growth response when exposed to 0.08 and 0.30 µL O3 L1. Significant differences exited among families for needle weight, shoot weight, and total weight. No differences were found among O3 treatments within a family, but patterns suggest some pitch pine individuals may be sensitive to low O3 while others are stimulated. Visible injury consisted of light chlorotic mottle on oldest needles. Discriminant function analysis indicated that growth responses were indistinguishable among families receiving no treatment; however, treated seedlings could be classified based on various height measurements and/or shoot weight. Differences in visible injury were apparent among families of seedlings treated with 0.40 µL O3 L1, indicating some pitch pine families are more sensitive to O3 than others.
Effects of Tebuthiuron on Characteristic Green Algae Found in Playa Lakes
Authors: Price David J. , Murphy Brian R. , Smith Loren M.
Published: July 2010

There are many studies on the effects of tebuthiuron (N‐(5‐(1,1‐dimethylethyl)‐1,3,4‐thiadiazol‐2‐yl)‐N,N′‐dimethylurea) on organisms, but only limited information regarding the impact that the herbicide has on green algae. Eleven species of green algae common to playa lakes were exposed tebuthiuron in 400‐mL microcosm cultures. The cultures were treated with 0.18 µg/mL tebuthiuron, simulating the highest concentration of the herbicide found in natural runoff from agricultural areas treated with > 2.24 kg/ha tebuthiuron. Sixty‐six cultures were treated before active growth (first treatment) and 45 separate cultures were treated after maximum growth (second treatment). The first treatment was used to simulate the exposure of algal communities to tebuthiuron from runoff during the wet months of May and June. The second treatment simulated exposure to the herbicide once the community was established. Production and nutrient uptake by treated algal cultures was decreased by the first treatment with tebuthiuron. Of the eleven algal species selected, only Bracteacoccus minor was significantly inhibited by tebuthiuron in the first treatment. Photosynthetic pigments, total cell counts, and packed cell volumes for cultures exposed to tebuthiuron in the first treatment were lower than controls (P < 0.05). Effects caused by the herbicide on the cultures were also evidenced by decreased water quality variables in cultures treated before active growth, with the exceptions of orthophosphates and chloride. No differences were detected between controls and treated samples 210 d after initial treatment with tebuthiuron. Once the algae reached stable cell numbers (second treatment), tebuthiuron demonstrated no significant (P < 0.05) effects on the cultures. This study indicated that runoff from agricultural fields treated with concentrations > 2.24 kg/ha tebuthiuron may adversely affect the green algal communities of playa lakes.
Trichloroethylene Residuals in the Capillary Fringe as Affected by Air‐Entry Pressures
Authors: Cary J. W. , McBride J. F. , Simmons C. S.
Published: July 2010

Trichloroethylene (TCE) was allowed to drain through columns of soil with the capillary water fringe controlled at various depths. Outflow was measured as well as the TCE content when TCE drainage stopped. Two soils, a sand and a loamy sand, with air‐entry values of 23 and 3 cm of water, respectively, were used. The sand with the large air‐entry value retained more TCE below the capillary water fringe following TCE drainage than the loamy sand with a smaller air‐entry pressure. The TCE below the saturated water fringe in both soils varied from almost 7% on a volume basis to <2%. The majority of the TCE in both soils was shown to resist further drainage when water was passed through the soils, suggesting the TCE phase was mostly fragmented. After 10 pore volumes of water was passed, the residual TCE content was 5.5 and 2.1% for the sand and loamy sand, respectively. Even though TCE has a greater specific gravity than water, it was shown in agreement with capillary theory, that TCE will not necessarily sink through the saturated water fringe to the bottom of an aquifer. Its tendency to do so is inversely proportional to the air‐entry pressure of the porous mineral phase. The results bring out several practical points for managing contaminated areas.
Trace Metals in Soil, Vegetation, and Voles from Mine Land Treated with Sewage Sludge
Authors: Alberici T. M. , Sopper W. E. , Storm G. L. , Yahner R. H.
Published: July 2010

Trace‐metal concentrations in soil, vegetation, and tissues of meadow voles (Microtus pennsylvanicus) were compared on a strip‐mined site reclaimed conventionally (control site) and with municipal sludge (treated site) in Somerset County, Pennsylvania, in March and April 1983. With the exception of Zn concentrations in birdsfoot trefoil (Lotus corniculatus L.), reclamation with municipal sludge did not increase trace metal concentrations in soil, vegetation, or meadow voles in comparison to the site reclaimed conventionally. Zinc concentration in birdsfoot trefoil from the site reclaimed with sludge was higher than that from the site reclaimed conventionally but was below phytotoxic levels. Concentrations of Cu, Zn, Co, Cd, and Ni in vole tissues were not significantly different between control and treated sites. However, Cr concentrations in kidney and bone and Pb concentrations in liver and bone were higher on the control site than on the treated site. Stomach analyses indicated that meadow voles preferred tall fescue (Festuca arundinaceae L.) and quackgrass (Agropyron repens L.) to birdsfoot trefoil and orchardgrass (Dactylis glomerata L.).
Application of Sewage Sludge and Other Amendments to Coal Refuse Material: III. Effects on Percolate Water Composition
Authors: Pietz R. I. , Carlson C. R. , Peterson J. R. , Zenz D. R. , Lue‐Hing C.
Published: July 2010

The effects of sewage sludge, lime, and gypsum on the chemical composition of percolate from acidic coal refuse material was studied at a Fulton County, IL, land reclamation site. Treatments consisted of a control, 542 dry Mg ha−1 anaerobically digested sewage sludge, 89.6 Mg ha−1 lime, 112 Mg ha−1 gypsum, and combinations of these amendments. The chemical composition of the percolate collected monthly (1976 to 1980) from suction lysimeters at a 1‐m depth reflected the treatments applied to the coal refuse material. Percolate pH, NH+4‐N and [NO−3 + NO−2]‐N levels were lowest in either the gypsum or control treatments and highest in the sewage sludge treatment. Percolate SO4 levels were lowest in either the control or sludge‐amended treatments and highest in the gypsum‐amended treatments. Levels of NH+4‐N and [NO−3 + NO−2]‐N in percolating waters from the sludge‐amended treatments declined with time, while P levels remained at <2.3 mg L−1. Percolate concentrations of Al, Cr, Cu, Fe, and Zn were lowest in the sewage sludge treatment and highest in gypsum‐amended treatments. Metal solubility in the percolate was affected by the chemical composition of the coal refuse material and the applied amendments. Percolate Al, Cd, Cr, Cu, Fe, Ni, and Zn levels were negatively related (P ≤ 0.01) to pH in the sludge and sludge + lime treatments. Estimated concentrations of the various metals at a specific pH indicates that the sludge and sludge + lime treatments were very effective in reducing metal leaching when the percolate pH was ≥5.0. The application rates of lime and sewage sludge based on theoretical procedures were effective for about 5 yr. For long‐term (>5 yr) reclamation, the effectiveness of the sludge and sludge + lime treatments would be better maintained by applying more sludge (1050 Mg ha−1) and (900 to 1350 Mg ha−1) + lime (134 to 189 Mg ha−1) initially. The factor of two difference between the theoretical and actual amounts of lime and sewage sludge needed in the field suggests that an added safety factor of one and a half to two for application of these amendments is desirable for long‐term reclamation of coal refuse material.
Copper Toxicity in Tomato Plants
Authors: Rhoads F. M. , Olson S. M. , Manning A.
Published: July 2010

Copper (Cu)‐containing fungicides and bactericides are used extensively for disease control on staked tomatoes (Lycopersicon esculentum Mill.) in North Florida. Since Cu moves very little in most soils, the potential for Cu buildup in tomato fields is substantial over a period of continuous tomato culture. The purpose of this research was to determine the Cu levels of soil and plant tissue, which are associated with reduced growth, and the influence of soil acidity on Cu uptake and growth response of tomatoes to soil Cu. Tomato plants were grown for approximately 6 wk in a greenhouse in pots of soil (Typic Paleudult) containing two levels of calcitic lime and six levels of copper hydroxide in a factorial treatment arrangement. Lime levels were 0 and 3.5 g kg−1 in Experiment 1 and 0 and 7.0 g kg−1 in Experiment 2. Copper levels were 0, 175, 350, 700, 1400, and 2800 mg kg−1 in Experiment 1 and 0, 44, 88, 175, 350, and 700 mg kg−1 in Experiment 2. Tissue‐Cu concentration was not a conclusive indicator of Cu toxicity in tomatoes. Soil pH and Mehlich 1‐extractable Cu provided sufficient information for determining if soil‐Cu levels were reducing plant growth. Near‐maximum Cu concentration in tomato tissue occurred at soil‐Cu levels above 104 mg kg−1. Plant growth was reduced with soil‐Cu levels above 150 mg kg−1 and soil pH below 6.5. However, soil‐Cu levels above 330 mg kg−1 were necessary to reduce plant growth with soil pH above 6.5.
Exchange of Nitrogen, Phosphorus, and Organic Carbon between Transplanted Marshes and Estuarine Waters
Authors: Craft C. B. , Broome S. W. , Seneca E. D.
Published: July 2010

Fluxes of N, P, and organic C were measured between irregularly flooded transplanted marshes and estuarine waters at two sites in North Carolina. Hydrologic flux was regulated by pumping estuarine water into the marsh, holding the water for 24 h and pumping the water out. Samples were collected from waters flowing into and out of each marsh and analyzed for salinity, N, P, and organic C. Concentrations of dissolved organic C were significantly higher in water flowing out of the two transplanted marshes compared to concentrations in inflow waters. In contrast, inflow waters contained significantly higher concentrations of phosphate than outflow waters. Phosphate flux was seasonal with maximum uptake by the marsh during the summer. Estimates of nutrient fluxes indicate that transplanted marshes export dissolved organic C (3–48 mmol m−2 event) and N (0.2–5.6) and import ammonium (300–600 µmol m−2 event) and phosphate (300–1000). The transplanted marshes are young communities that lack the large soil organic matter reservoirs and reducing environment characteristic of many natural marshes. These systems probably will continue to import ammonium and phosphate until the soils become reduced and soil nutrient reservoirs develop.
Pressurized Layer Reduces Transport through Compacted Clay Liners
Authors: Kluitenberg G. J. , Horton R.
Published: July 2010

Compacted clay liners are often used in hazardous waste surface impoundments and landfills to provide a physical barrier to the flow of leachate. If a liner develops cracks or regions of high conductivity, convective fluxes can lead to increased chemical transport through the liner. In this study, we investigate the use of a pressurized layer of coarse material sandwiched between two compacted clayey soil layers to eliminate the hydraulic gradient across the upper layer. Our hypothesis is that such a system would limit convective transport through cracks or regions of high conductivity. Miscible displacement experiments were conducted using compaction permeameters filled with layered and unlayered soil materials. Experiments were carried out with and without a “worst case” hole penetrating the soil columns vertically. The experimental results show that, by using the pressurized interlayer in the presence of a worst case hole, both mean solute travel times and times to first breakthrough were significantly greater than when no interlayer was used. Travel times and time to first breakthrough were also increased when the pressurized interlayer was introduced in a column not containing a hole. The experimental results also serve to demonstrate the devastating effect of a small crack or hole on solute transport.
Sample Size Requirements for Estimation of Throughfall Chemistry Beneath a Mixed Hardwood Forest
Authors: Kostelnik K. M. , Lynch J. A. , Grimm J. W. , Corbett E. S.
Published: July 2010

Six rainfall events were intensively sampled below a mixed hardwood forest canopy in central Pennsylvania to determine sample size requirements for estimation of thronghfall volumes and ionic concentrations. Evaluation of the ionic parameters of thronghfall revealed that the concentrations of most major ions were nonnormally distributed. Differences in the distributions of concentrations were found to occur between ions as well as between storms. Significant departures from normality were mainly due to right‐skewness. Only H+ exhibited a left skewed sample distribution. None of the basic transformations were effective in normalizing all parameters. A high degree of spatial variability was observed for each of the chemical parameters. Nitrate and hydrogen ions (NO−3 and H+), were found to be the least variable, whereas vegetatively mobile ions such as K+ and Mg2+ exhibited the greatest variability. Because of high event‐to‐event variation in the distributions of ion concentrations, specific sample‐size requirements should be estimated for each ion through preliminary sampling of thronghfall precipitation from several storms.
Aboveground Dissolution of Tebuthiuron Particles Placed Beneath the Crowns of Small Pinyon Trees
Authors: Van Pelt Nicholas S. , West Neil E.
Published: July 2010

Placement of large tebuthiuron {N‐[5‐(1,1 dimethylethyl)‐1,3,4‐thiadiazol‐2yl]‐N,N′‐dimethylurea} particles (briquettes) beneath tree canopies inhibits rainfall‐driven mobilization of the active ingredient. Briquette displacement and dissolution patterns were studied at two central Utah sites after 8‐month (cool seasons) and 4‐month (summer) exposure periods. Thirty‐two 1.8 g (13% a.i.) Graslan Brush Bullets per tree were placed at the dripline, midcrown, and stem base of 24 similar pinyon pine (Pinus edulis Engelm. and P. monophylla Torr. & Frem) saplings. The effects of site, placement, and direction from the stem were analyzed via a balanced, nested factorial experiment. Residues were entirely relocatable, indicating that overland flow, wind, and animals did not move briquettes. The influence of individual trees, placement, and direction strongly depended on season. Summer thunderstorms were three times more effective per unit of precipitation than winter rain and snow. Subcanopy placements permitted 65% as much dissolution as the exposed interspace, with stemflow more effective than throughfall in summer. Directional effects caused by storm paths were mild, and only evident at the dripline after summer exposure. Stem‐base applications or smaller particles should minimize site, season, and tree effects and ensure rapid, uniform control of woody‐weed regrowth with minimal undesired impacts.
Water Treatment Sludge Influence on the Growth of Sorghum‐Sudangrass
Authors: Heil D. M. , Barbarick K. A.
Published: July 2010

Disposal of water treatment sludges (freshwater coagulant sludges), which are primarily amorphous Fe and Al compounds, poses a management problem for most municipalities in Colorado and other states. Previous studies indicate that water treatment sludges have a high capacity to fix P and that plant P deficiencies develop when plants are grown in sludge‐soil mixtures. No attempt has been made to quantify the ability of water treatment sludges to fix P to determine specific application rate recommendations. This research was initiated to determine acceptable application rates of three types of water treatment sludges added to the Colby (Ustic Torriorthent; pH = 7.5) and Red Feather (Lithic Cryoboralf; pH = 5.5) soils. A greenhouse study was conducted utilizing mixtures of an alum, iron, or organic polymer sludge combined with each of the two soils at rates of 0, 5, 10, 15, 20, and 25 g kg−1. Three cuttings of sorghum‐sudangrass [Sorghum bicolor L. Moench ‘NB280S’‐S. sudanense (Piper) Stapf] were taken. The Langmuir adsorption isotherm approach gave an accurate prediction of the relative fixation capacity of different sludges and consequently the effect of different sludge rates on P uptake by plants. Total plant yield and plant uptake data indicated that positive plant growth responses to sludge above those in the control (0 g kg−1) were the result of improved Fe availability in the Colby soil, and possibly increased soil pH in the Red Feather soil. Yields declined at higher sludge application rates (15 – 25 g kg−1) as compared to low application rates (5 – 10 g kg−1) probably due to increased P fixation by sludge. Plant concentrations of Al, Cu, Mn, Ni, and Pb were not high enough to decrease plant growth; however, Cd concentrations associated with 20 and 25 g alum sludge kg−1 Red Feather soil were greater than 2 mg kg−1. This is the upper limit reported for normal concentrations in plants and it may pose a threat to livestock that consume this forage.
Characterization of Phosphorus in Sludge Extracts Using Phosphorus‐31 Nuclear Magnetic Resonance Spectroscopy
Authors: Hinedi Zeina R. , Chang A. C. , Lee R. W. K.
Published: July 2010

Nuclear magnetic resonance spectroscopy (31P NMR) was used to characterize the phosphorus (P) extracted from selected municipal sewage sludges. Aqueous and nonaqueous extraction schemes were studied. The trichloroacetic acid/KOH two‐step extraction and the 0.5 M NaOH extraction were effective in recovering P from sludges. It was found that the P distribution pattern is sludges was affected by the sludge digestion processes. Almost all of the P in anaerobically digested sludges was inorganic. In the waste‐activated sludge and aerobically digested sludges, more than 50% of the total P was present as P‐monoesters and P‐diesters. Several experiments were conducted to confirm P‐diester peak assignment. Incubation of the sludge with ribonuclease caused a decrease of the peak in the P‐diester region, indicating that at least a part of the P‐diesters is in the form of RNA. Results of a dialysis experiment appeared to indicate that P‐diesters were broken down from the molecular weight >1000 material to their lower molecular weight components during sludge digestion. The peaks appearing in the 31P NMR spectra of sludge‐borne phospholipids were tentatively assigned to phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, and phosphatidylglycerol or diphosphatidylglycerol.
Adsorption of Sulfate by Kaolinite and Amorphous Iron Oxide in the Presence of Organic Ligands
Authors: Inskeep William P.
Published: July 2010

The ability of soils to adsorb SO4 is an important factor in determining the effect of acidic deposition on the transport of H+ and cations in terrestrial ecosystems. However, the role of soluble organic acids and humic substances on the adsorption of SO4 is poorly understood. Consequently, this study was conducted to determine the effects of soluble organic ligands on the adsorption of SO4 by amorphous iron oxide (AIO) and kaolinite (KGa‐2). Adsorption experiments were conducted by titrating 50 mM K2SO4 with suspensions of KGa‐2 (146‐583 m2L−1) or AIO (324 m2L−1) in 0.01 M KCl, at pH 4.3 and 25 °C. Sulfate adsorption was studied over a range in total SO4 of 0.01 to 2.5 mM in the absence and presence of organic ligands including Seward humic and fulvic acid, tannic acid, citric acid, oxalic acid, and gallic acid. Sulfate adsorption capacities in the absence of organic ligands were 3.5 and 1.3 µmolc m−2 at 324 m2L−1 AIO and 583 m2L−1 KGa‐2, respectively. Humic and tannic acid present at 1.4 to 3.6 mM total soluble C reduced SO4 adsorption by KGa‐2 at total SO4 levels below 0.12 mM. Humic, tannic, citric, gallic, and oxalic acid were all effective at inhibiting SO4 adsorption by AIO. In several cases the percent of SO4 adsorbed was reduced from near 100 to zero at total SO4 levels below 0.12 mM. The amount of inhibition was related to the quantity of oxygen‐containing functional groups added rather than the total soluble C. These results indicate that organic acids compete for SO4 adsorption sites and that the presence of organic acids in soil solutions will influence SO4 adsorption capacities.
Heavy Metal Concentrations During Ten Years of Sludge Treatment to an Old‐Field Community
Authors: Levine M. Beth , Hall A. Tilghman , Barrett Gary W. , Taylor Douglas H.
Published: July 2010

Heavy metal concentrations were determined in three trophic levels of an old‐field community treated for 10 consecutive years with sewage sludge. The study site consisted of sludge‐treated, fertilizer‐treated, and control plots. Cadmium concentrations were highest each year in soils, vegetation, meadow vole (Microtus pennsylvanicus Ord.) livers, and earthworms (Lumbricus rubellus Hoffmeister, L. terrestris L.) from sludge‐treated plots. Mean Cd concentrations in sludge decreased from 59.0 mg kg−1 in 1978 to 19.8 mg kg−1 in 1987, whereas Cd concentrations in soil increased from 1.13 mg kg−1 in 1979 to 1.94 mg kg−1 in 1987. Plant species in sludge plots had significantly higher Cd concentration values than those collected from fertilizer or control plots. No yearly increase in Cd content was observed in meadow vole liver or kidney. Cadmium concentrations in earthworms were significantly greater in 1981 (139.2 mg kg−1) than in 1987 (60.9 mg kg−1). Copper concentrations were highest in soils, giant foxtail (Setaria faberii Hermm.), and earthworms from sludge‐treated plots. Mean Cu concentrations in sludge ranged from 320.0 mg kg−1 in 1978 to 380.6 mg kg−1 in 1984. Copper concentrations in soil ranged from 14.7 mg kg−1 in 1979 to 36.9 mg kg−1 in 1986. Vegetation in sludge plots concentrated Cu less than vegetation in fertilizer or control plots. Cu concentrations in meadow vole liver decreased from 5.0 to 3.1 mg kg−1 and in kidneys from 4.9 to 3.3 mg kg−1 in 1978 and 1987, respectively. Copper concentration in earthworms ranged from 17.1 mg kg−1 in 1981 to 23.0 mg kg−1 in 1987. Although Pb concentrations in sludge declined from 473.0 mg kg−1 in 1978 to 243.0 mg kg−1 in 1987, mean Pb concentrations in soil increased from 19.0 mg kg−1 in 1979 to 48.4 mg kg−1 in 1986. However, only giant foxtail in sludge‐treated plots significantly concentrated Pb. Mean Pb concentrations in earthworms ranged from 8.06 mg kg−1 in 1986 to 16.8 mg kg−1 in 1987. Mean Zn concentrations in sludge ranged from 865.8 mg kg−1 in 1987 to 1281.0 mg kg−1 in 1984. Zinc concentrations in soils increased from 52.4 mg kg−1 in 1979 to 107.2 mg kg−1 in 1987. Zinc concentrations varied substantially among plant species; mean Zn concentrations in 1987 ranged from 41.0 mg kg−1 for Rubus frondosus Bigel. (a perennial) to 97.3 mg kg−1 for giant foxtail (a summer annual). Zinc concentrations in earthworms decreased from 1218.5 mg kg−1 in 1981 to 615.5 mg kg−1 for 1987. The detritivore trophic level bioconcentrated heavy metals more than producer or primary consumer levels.