bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological Monitoring of an Agricultural Food Chain: Soil Cadmium and Lead in Ruminant Tissues
Authors: Brams Eugene , Anthony William , Weatherspoon Lindsey 
Published: July 2010

AbstractLow‐level contamination of a sandy soil with toxicants Cd and Pb at 0.01 to 9.0 and 3.0 to 54.0 mg kg−1 soil induced a significant toxicant accumulation in sudan‐sorghum hay [Sorghum sudanense (Piper) Stapf‐S. bicolor (L.) Moench] (0.5–5.0 and 0.2–1.5 mg kg−1 dry biomass), respectively. Ingestion of 22 to 222 mg Cd kg−1 body wt. by pregnant dairy goats (Capra hircus) from the consumption of hay over 98 d resulted in a significant, but relatively diminutive accumulation of Cd in the doe livers (0.01–0.02 mg kg−1) and brain cortex (0.002–0.007 mg kg−1) fresh wt., but not in doe kidneys and blood averaging 0.028 and 0.002 mg Cd kg−1 fresh tissues, respectively. Fetal blood and liver accumulated 2.0 and 4.0 mg Cd kg−1 fresh tissue, respectively, and fetal kidney exhibited a weak response (0.03–0.47 mg Cd kg−1 fresh tissue) to Cd ingested by the pregnant does. Consumption of 240 to 1230 µg Pb kg−1 body wt. induced 1.0 to 43.0 mg Pb kg−1 fresh tissue in the doe brain cerebellum, but not in the doe liver and blood averaging 0.09 and 0.017 mg Pb kg−1 fresh tissue, respectively. Fetal liver and blood averaged 0.043 and 0.014 mg Pb kg−1 tissue. Only minuscule amounts of soil Cd and Pb were retained in the select animal tissues via the ingestion of this hay. Only one‐ten‐millionth of labile soil Cd and Pb, respectively, accumulated in the select tissues of the pregnant does via the hay pathway. All these amounts were comparable to the norm. If these select animal tissues were used as food, no deleterious effect to human health should be induced.
Influence of Binary Interactions of Arsenate, Molybdate, and Selenate on Yield and Composition of Alfalfa
Authors: Khattak Riaz A. , Haghnia G. H. , Mikkelsen R. L. , Page A. L. , Bradford G. R. 
Published: July 2010

AbstractArsenic (As), selenium (Se), and molybdenum (Mo) are known to coexist in the soil solution as anions and thus may exert antagonistic or synergistic effects on their absorption by and translocation within plants. To evaluate the effects of binary interactions [As(V) × Se(VI), Se(VI) × Mo(VI) and As(V) × Mo(VI)] on growth and composition of alfalfa (Medicago sativa L.), three glasshouse sand culture experiments were conducted. Treatments applied in the half‐strength Hoagland's solution alone and in all possible factorial combinations for a given interaction consisted of 0, 0.25, 0.5, and 1.0 mg As(V) L−1 added as Na2HAsO4; 0 , 0.5, and 1.0 mg Se(VI) L−1 added as Na2SeO4; and 0.01, 1, 3, and 5 mg Mo(VI) L−1 added as Na2MoO4. Shoots were harvested three times and roots at the termination of the experiment. Plant tissues were dried, weighed, digested and analyzed for total As, Se, and Mo. Added Mo(VI) concentrations in the nutrient solutions had no significant effect on the tissue yield of alfalfa. Arsenic showed some adverse effect on shoot and root yields. The highest Se(VI) treatment decreased alfalfa shoot yield by 13.7 to 44.2% and root yield by 33% to 56.1%. The tissue As, Se, and Mo concentrations increased correspondingly with the increasing solution concentrations. At equal levels in the solution, alfalfa accumulated Se > Mo ≫ As. Increasing As(V) in solution caused significant increases in shoot Se concentrations and uptake, whereas solution Se(VI) showed a strong antagonistic effect on As uptake. The Se treatments significantly (P ~ 0.05) increased concentrations and uptake by shoot and root at all levels of solution Mo, except 0.01 mg L−1 where 1.0 mg Se L−1 increased Mo concentration, but had no significant effect on Mo uptake. Increasing Mo levels in the nutrient solution showed no significant effect on Se concentration and uptake by root. However, at 1.0 mg Se(VI) L−1, shoot Se concentration increased significantly at 3.0 and 5.0 mg Mo L−1. The solution As(V) showed no significant effect on tissue Mo at 0.01 and 1.0 mg Mo(VI) L−1 but increased Mo concentrations in shoots significantly (P ≤ 0.05) at 3.0 and 5.0 mg Mo(VI) L−1. These interactions may help to understand the complex interactions in soilplant systems. Based on the observed elevated tissue concentrations of As, Se, and Mo, these results might have important environmental implications for phytotoxicity to plants and foraging animals.
Vertical and Lateral Components of Soil Nutrient Flux in a Hillslope
Authors: Gaskin J. W. , Dowd J. F. , Nutter W. L. , Swank W. T. 
Published: July 2010

AbstractThe vertical and lateral components of chemical flux during storm events were investigated in a Typic Hapludult to assess their importance in understanding the effects of atmospheric deposition on hillslope sites. Vertical and lateral water flux were calculated from soil water potential data and hydraulic conductivity curves. Throughfall, stemflow, forest floor leachate, and soil solution from the BA, Bt, and BC horizons were sampled and analyzed for SO4, NO3‐N, Cl, HCO3, H, K, Ca, Mg, and Na. Total lateral flow as a ratio of total vertical flow averaged 0.23 and 0.30 in the A and BA horizons, respectively, indicating lateral fluxes were an important path of nutrient movement in the surface horizons. The highest lateral flow occurred in the A horizon during dry antecedent moisture conditions and in the BA horizon during wet antecedent moisture conditions. Fluxes of all ions except HCO3, NO3‐N, and H peaked in the forest floor leachate and the BA soil solution, then decreased with depth. Decreases of SO4 flux between the BA and BC horizons could not be explained by the lag of solute movement or by lateral solute losses, demonstrating the system was an effective SO4 sink.
Comparison of Tracer Mobilities under Laboratory and Field Conditions
Authors: Everts Christopher J. , Kanwar Rameshwar S. , Alexander E. Calvin , Alexander Scott C. 
Published: July 2010

AbstractTransport of bromide, nitrate, lithium, and Rhodamine WT were compared in a repacked soil column and in a tile drained in a cropped field. Breakthrough of lithium and Rhodamine WT in a soil column was delayed by adsorption as compared to nitrate and bromide in the same column. When applied with irrigation water above a tile drain line, concentrations of all the tracers peaked in tile water 70 min after the start of an irrigation, then declined as irrigation continued. Tile flow responded to irrigation by increased flow and increased tracer concentration within 25 min after the start of an irrigation. Total percentage of tracers reaching tile flow from two tracer irrigations were 3.0, 2.5, 0.46, and 0.15%, respectively, of the nitrate, bromide, lithium, and Rhodamine WT applied with irrigation water. Of these losses, 67% of the cation‐exchanged lithium and 83% the adsorbed Rhodamine WT removed in tile flow during 56‐h of tile flow did so within 1 h after the irrigation ended. Proportion of nitrate and bromide losses in tile flow during the same time period were 40 and 35%, respectively.
Development and Testing of Open‐Top Chambers for Exposing Large, Perennial Plants to Air Pollutants
Authors: Mandl Richard H. , Laurence John A. , Kohut Robert J. 
Published: July 2010

AbstractTo study the effects of air pollutants on large perennial plants, two designs of large, open‐top chambers were tested in wind runnel studies and subsequent field trials. Flow visualization of air patterns in the wind tunnel showed that a frustum and inner baffle plate covering 50% of the top surface provided the best exclusion capabilities. This was quantified by measurement of pollutant distribution in scale models. Prototype chambers were erected around grape (Vitus sp.) vines in a commercial vineyard and evaluated over two growing seasons. Exclusion efficiencies of 80 to 95% were found during the test period. The rain shadow caused by the frustum was significant with losses greatest near the walls. The average increase in leaf temperature between ambient and within the chamber was 2.5 °C. Light intensity was reduced 14 and 22% in the circular and rectangular chamber, respectively. Although there is some modification of the plant environment, the chambers provide a suitable environment during the growing season for air pollution studies with large perennial plants.
Mechanism of Pyrite Oxidation in Aqueous Mixtures
Authors: Brown A. D. , Jurinak J. J. 
Published: July 2010

AbstractThe rate of pyrite oxidation in aqueous mixtures was studied at 25 °C for periods up to 3 wk. Dissolved plus citrate‐dithionite‐extractable Fe was used to measure the extent of reaction. Pyriteoxidation rate was independent of time (zero order) in the presence of NaClO4, CaCO3, and NaHCO3. Oxidation rate was a linear function of substrate concentration. Oxidation rates increased with pH. Solutions of Cl−, SO2−4, and diethylenetriamine pentaacetic acid (DTPA) inhibited pyrite oxidation. The data are consistent with a surface‐controlled reaction with Fe3+ as the rate‐controlling oxidant. The effect of OH−, Cl−, SO2−4, and DTPA on oxidation rates is explained by the relative reactivity of each of these in ligand exchange during an inner‐sphere electron transfer. It is suggested that OH− is the rate‐determining bridging ligand between Fe3+ and the pyrite surface. This reaction is compatible with recently proposed surface‐reaction mechanisms.
Chemical Effects of Saline Irrigation Water on a San Joaquin Valley Soil: I. Column Studies
Authors: Thellier Catherine , Sposito Garrison , Holtzclaw Kenneth M. 
Published: July 2010

AbstractA glasshouse soil column experiment was performed to characterize salinity and sodicity developed from waters of differing composition applied to a representative soil from the San Joaquin Valley of California. The soil column experiment was designed to simulate physicochemical conditions in a field experiment conducted in the western San Joaquin Valley, where an Entisol above a shallow, saline aquifer was irrigated with waters of varying quality. Columns 0.46 m long containing the Entisol were leached with “California Aqueduct water” (EC = 0.72 dS m−1, SAR = 4 molc 1/2m−3/2) or with saline “well water” (EC = 8 ds m−1, SAR = 13 molc 1/2m−3/2) for periods up to 1 yr. When a simulated “aquifer” was 0.43 m below the soil surface, leaching with aqueduct water produced a positive downward gradient of soluble salt concentrations and exchangeable Na, whereas leaching with well water produced a dramatic increase of sodicity at the soil surface and a zone of soluble bivalent cation accumulation about 0.2 m below. These effects reflected the combined influence of the applied water quality and evaporative capillary rise from the saline “aquifer.” After the simulated “aquifer” was withdrawn, soil saturation extracts indicated equilibration with the applied waters after 0.5 to 1 yr, the rate being greater under leaching with aqueduct water. The saturation extract and drainage effluent for the soil receiving aqueduct water became more dilute, producing calcite dissolution and increasing exchangeable Ca, with a consequent decline in sodicity. The soil receiving well water showed an increase in exchangeable Na at the expense of exchangeable Ca, with little or no change in exchangeable K and Mg. At the completion of the experiment, the soil irrigated with well water had become more saline and sodic but, since EC was sufficiently high as compared to SAR, no major permeability problems with the soil were expected. Therefore, from the results of this study, the reuse of saline drainage water would appear to be suitable for agricultural purposes provided that salt‐tolerant crops were grown.
Chemical Effects of Saline Irrigation Water on a San Joaquin Valley Soil: II. Field Soil Samples
Authors: Thellier Catherine , Holtzclaw Kenneth M. , Rhoades J. D. , Sposito Garrison 
Published: July 2010

AbstractRepresentative samples were collected from the surface horizon of an Entisol in field plots that had received applied waters of differing quality over a 5‐yr period while cropped with cotton (Gossypium sp.), wheat (Triticum sp.), and sugarbeets (Beta vulgaris L.). Irrigation was either with California Aqueduct water, saline well water, or a 1:1 mixture of the two. The soil samples were analyzed for saturation extract electrolytic conductivity (ECe); soluble and exchangeable cations; and carbonate and gypsum content. Both salinity and sodicity increased in the soil samples with decreasing applied water quality, and all of the samples were more saline and sodic and contained more calcite than at the initiation of the field experiment. The samples from plots receiving well water had developed values of ECe and sodium adsorption ratio (SARe), as well as an exchangeable sodium percentage‐SARe relationship, identical to those observed after 1 yr in a companion soil column experiment. The samples from plots receiving aqueduct water were more saline and sodic than in the corresponding soil column experiment, however, probably because of less effective leaching in the field experiment. These results confirmed the hypothesis that the chemical properties of the field soils would be determined by the interplay between the applied water and evaporative capillary rise from the shallow aquifer. Since the increased salinity of the soil samples compensated for their increased sodicity, no permeability problems were expected, and irrigation with saline water should be successful for salt‐tolerant crops if leaching were adequate.
Control of Arborescent Vegetation below Power Lines with Wastewater Sludge
Authors: Grenier Yvon , Couillard Denis 
Published: July 2010

AbstractA 1‐yr field study was conducted to determine whether fertilization with wastewater sludge could favor growth of herbaceous and shrub species to inhibit or eliminate the growth of tree species under power lines. Results show that a significant proportion of the trees died: mortality ranged from 35 to 100% on plots that received 160 Mg ha−1 of sludge, and ranged from 0 to 31% on control plots. The surviving trees showed accelerated growth. Means of height increments ranged from 17 to 86 cm on plots receiving 80 Mg ha−1 of sludge, and ranged from 5 to 31 cm on control plots. Sludge applications also decreased regeneration success of trees in the current year, with a minimum of 0.8 and a maximum of 7.0 new seedlings per 12.5 m2 on treated plots, as compared to 14.0 new seedlings on control plots. With the short duration of this preliminary study, it is concluded that the herb and shrub strata did not have sufficient time to fully develop in a single growing season and that the hypothesis remains to be verified.
Growth and Elemental Content of Slash Pine 16 Years after Treatment with Garbage Composted with Sewage Sludge
Authors: Jokela E. J. , Smith W. H. , Colbert S. R. 
Published: July 2010

AbstractLandspreading of organic wastes remains an environmentally acceptable option for recycling nutrients. This study assessed tree growth and elemental tissue concentrations in a slash pine (Pinus elliottii Engelm.) plantation treated 16 yr previously with four rates (0, 112, 224, 448 Mg ha−1) of municipal garbage composted with sewage sludge. Tree growth was significantly greater where garbage compost was applied. Stem wood biomass increased from 55.7 to 94.7 Mg ha−1, a 1.7‐fold increase over the control for the heaviest garbage application rate. Annual tree basal area increment responses were also largest and most long‐lasting (up to 9 yr) for the 448 Mg ha−1 rate. Significant but modest treatment associated increases in concentrations of N, P, B, Fe, Al, and Zn in pine tissues (foliage, stem wood), and P and Ca in Rubus spp., a dominant understory plant, were found after 16 yr. Analysis of pine xylem tissues corresponding to the juvenile and post‐crown closure growth phases revealed significantly higher concentrations of K, Ca, Mg, Cu, Al, and Zn in the latter period. Results suggest that landspreading and recycling degradable organic wastes in forests can increase tree and understory growth without long‐term deleterious ecosystem effects. The applicability of these results to a typical community in a forested landscape is illustrated.
Leaf Gas Exchange of Maize Plants Fumigated with Sulfur Dioxide
Authors: Gerini O. , Guidi L. , Lorenzini G. , Soldatini G. F. 
Published: July 2010

AbstractLeaf gas exchange was measured in maize (Zea mays L.) plants that had been exposed continuously for a period of 4 wk to a range of SO2 concentrations applied in fumigation chambers. Exposure to a constant SO2 level of 43 and 71 nLL−1 induced a decrease in the apparent photosynthesis and quantum yield, and an increase in the stomatal conductance and transpiration rate in comparison to the charcoal‐air filtered controls. This would suggest that the reduction in photosynthesis observed was mainly due to nonstomatal components, i.e., the direct effect of SO2 on the mesophyll.
Geochemical Factors Controlling the Mobilization of Inorganic Constituents from Fossil Fuel Combustion Residues: I. Review of the Major Elements
Authors: Mattigod S. V. , Rai Dhanpat , Eary L. E. , Ainsworth C. C. 
Published: July 2010

AbstractLarge quantities of fossil fuel combustion (FFC) wastes, such as fly ash, bottom ash, flue gas desulfurization (FGD) sludge, and oil ash are being disposed of on land. There is a need to accurately assess the mobilization of elements that results from the weathering of these wastes. To help meet this need, available data on physical, chemical, mineralogical, extract, and leachate characteristics have been compiled and reviewed, and a comprehensive approach to understanding how major elements are mobilized from fossil fuel wastes is described. Many of the physical properties of fly ashes overlap those of bottom ashes; similar data for FGD sludge and oil ashes are sparse. One taxonomic and three utilitarian classification schemes have been proposed for fly ashes. However, no taxonomic system is applicable to all FFC wastes. The ranges of concentrations of Al, Ca, and Fe found in these wastes were within the ranges of their concentrations in soils. Concentrations of K, Na, Mg, and S in some FFC wastes may exceed their highest concentrations in soils. The matrix of fly ashes consists principally of quartz, glass, and mullite. As minor components in fly ashes, anhydrite, lime, periclase, hematite, and magnetite are reported frequently. A minor fraction of many of the major elements may also be present in a glassy phase. The principal compounds in FGD sludges are sulfites, sulfates, carbonates, and hydroxides of Ca. The oil ashes contain mainly sulfates and oxides of Al, Na, Fe, and Mg. Water extracts of FFC wastes contain significant fractions of Ca, Mg, K, and Na, a fact that confirms the presence of these elements in highly soluble forms. Leaching studies conducted using fly ash columns have shown that initial leachates contain high concentrations of Ca, Na, K, and S and that as leaching continues these concentrations decline and reach steady states. Usually only negligible fractions of Si, Al, Fe, and Mg are leached from fly ash columns. In this article, a comprehensive approach is suggested, one that combines thermochemical principles with chemical and mineralogical data to predict the upper limits of elemental concentrations that can be attained in leachates from weathering FFC wastes. This thermochemical approach has shown that secondary solid phases may control concentrations of Al, Ca, and S measured in extracts of fly ashes and FGD sludges and in pore waters from fly ash lysimeters at a field site. Characterization of weathered wastes and improved thermochemical data for secondary solid phases in these wastes will be useful for understanding and predicting the chemistry of leachates.
Tracked Vehicle Impacts on Vegetation at the Pinon Canyon Maneuver Site, Colorado
Authors: Shaw R. B. , Diersing V. E. 
Published: July 2010

AbstractThe effects of military tracked vehicle maneuvers on the vegetation of the Pinon Canyon Maneuver Site (PCMS), southeastern Colorado, were assessed from 1985 to 1987. Tracking decreased plant basal and litter cover and increased bare ground. The immediate effect of tracking was to reduce perennial warm‐season grasses [primarily blue grama, Bouteloua gracilis (H.B.K.) Lag. ex. Griffith] followed by the invasion of annual cool‐season grasses [sixweeks grass, Vulpia octoflora (Walt.) Rybd., and little barley, Hordeum pusillum Nutt.] and annual warm‐season forbs [sunflower, Helianthus annuus L., russian thistle, Salsola iberica Sennen & Pau, and kochia, Kochia scoparia (L.) Schrab.]. In untracked areas, herbaceous plant composition did not change; however, litter increased and bare ground and basal cover decreased. Changes in cover in untracked areas was attributed to above average precipitation and the cessation of domestic livestock grazing. Overall (tracked plus untracked areas), total cover increased on PCMS, but the proportion of annual cover also increased. Woody plant density decreased an average of 9% from 1985 to 1987. Long‐term management of the soil and vegetative resources of PCMS are discussed.
Biodegradation of a Gas Oil Applied to Aggregates of Different Sizes
Authors: Mott Stella C. , Groenevelt Pieter H. , Voroney R. Paul 
Published: July 2010

AbstractLand treatment of oily wastes involves repeated application and tillage cycles to promote biodegradation of the waste. Tillage intensifies greater than current practices would result in smaller aggregates, promote oil‐soil interaction, and likely improve waste biodegradation. Due to the cyclical nature of treatment, it was unclear whether the obvious effect of oil‐soil mixing after application or the more subtle effect of soil surface preparation before the next application would be the primary effect of increased tillage intensity. Previously untreated soil was sieved into aggregates of the following size ranges: coarse (19–25 mm in diam.), medium (5–10 mm), and fine (1–2 mm). Oily waste, emulsified in sufficient water to bring the soil to 25% water content, was evenly applied to the surface of aggregates from each size range. Treated and untreated samples were incubated for 14 d at 25°C. Biodegradation was measured by CO2 entrapment in KOH. After 14 d, the coarse and medium aggregates were ground to approximately 2 mm. Incubation of all samples was resumed without further waste application. A one‐component exponential model regression indicates that application to fine aggregates resulted in a larger available mineralizable carbon pool, with more CO2 produced from treated fine aggregates. The effects are attributed to the larger available surface area. Although grinding caused a CO2 flush lasting several days, the pregrinding pattern was soon reestablished. The laboratory results suggest that waste biodegradation is inversely proportional to aggregate size before application, and that soil surface preparation into fine aggregates may be more beneficial than tillage after application.
Lead Mobility within the Xylem of Red Spruce Seedlings: Implications for the Development of Pollution Histories
Authors: Donnelly John R. , Shane John B. , Schaberg Paul G. 
Published: July 2010

AbstractDevelopment of Pb pollution histories using tree ring analyses has been troubled by possible mobility of Pb within stem xylem. In a 2‐yr study, we exposed red spruce (Picea rubens Sarg.) seedlings to Pb during one growing season, with Pb excluded in either the previous or following growing season. Lead levels within xylem rings and bark were subsequently determined using atomic absorption analyses. Lead concentrations in tissues from exposed seedlings were significantly higher than controls, and significant Pb concentrations were found in xylem formed during periods of Pb exclusion. Routes of Pb movement are uncertain, but were most likely acropetal from temporary storage sites in the roots.