bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behavior Assessment Model for Trace Organics in Soil: I. Model Description
Authors: Jury W. A. , Spencer W. F. , Farmer W. J. 
Published: July 2010

AbstractA mathematical model is introduced for describing transport and loss of soil‐applied organic chemicals. The model assumes linear, equilibrium partitioning between vapor, liquid, and adsorbed chemical phases, net first order degradation, and chemical movement to the atmosphere by volatilization loss through a stagnant air boundary layer at the soil surface. From these assumptions and the assumption of steady state upward or downward water flow, an analytic solution is derived for chemical concentration and volatilization flux.This model, which is intended to classify and screen organic chemicals for their relative susceptibility to different loss pathways (volatilization, leaching, degradation) in the soil and air, requires knowledge of the organic carbon partition coefficient (Koc), Henry's constant (KH), and net, first‐order degradation rate coefficient or chemical half‐life to use on a given chemical.Illustration of the outputs available with the model is shown for two pesticides, lindane (γ‐1,2,3,4,5,6‐hexachlorocyclohexane) and 2,4‐D [(2,4‐dichlorophenoxy)acetic acid], which have widely differing chemical properties. Lindane, with a large Koc, large KH, and small degradation rate coefficient, is shown to be relatively immobile, persistent, and susceptible to volatilization. 2,4‐D, with a small Koc, small KH, and large degradation rate coefficient, is mobile and degrades rapidly, but is only slightly susceptible to losses by volatilization.
Fate of Oxygen and Refractory Organics in Marmot Basin Streams: Seasonal Variations
Authors: Telang S. A. , Hodgson G. W. 
Published: July 2010

AbstractA conceptual process reactor model with input‐output functions developed for the mountain streams of the Marmot Basin (Alberta, Canada) showed seasonal trends in the conversion of organic matter. Based on mass balance data, organic compounds (e.g., tannins and lignins), and total organic C showed net gains in the stream waters in winter; in spring, the compounds tend to be depleted in waters; in the fall, humics and tannins and lignins underwent net depletion. The indicated changes of accumulation and depletion ranged from +95 to −42% of incoming mass. The chemical O2 demand showed gains in the stream waters throughout the season. The biological O2 demand showed little change throughout the seasons. Photochemical processes appeared to be important processes in the conversion of organic matter in clear, cold mountain streams of the Marmot Basin. Biological uptake of refractory compounds appeared to be a minor process.
Mobility and Retention of Heavy Metals in Sandy Soils
Authors: Miller W. P. , Mc Fee W. W. , Kelly J. M. 
Published: July 2010

AbstractThe sandy soils of industrialized northwestern Indiana are contaminated with aerially deposited Cd, Zn, Cu, and Pb, which are retained largely in the upper 5 cm of soil. To evaluate the leaching of these metals, intact soil cores of the Oakville (Typic Udipsamment) series sampled from forested sites in this area were leached in the laboratory with acidified or metal‐containing solutions corresponding to 1 or 10 y of simulated rainfall. Metals in the leachate were below detection limits, and analyses of core sections showed that the applied Cd, Zn, Cu, and Pb were concentrated in the litter layer and top 2.5 cm of soil. Adsorption experiments performed on 0‐ to 2.5‐cm samples of Oakville soil containing initial levels of 5 µg Cd, 1000 µg Zn, 100 µg Cu, and 200 µg Pb/g soil demonstrated that these soils could retain up to twice the amounts of metals initially present. A similar soil with lower pH and less organic matter adsorbed less of all the metals, while showing higher retention of Cu and Pb compared with Cd and Zn. Sequential extraction of the sorbed metals showed that chelation by organic matter (Na4P2O2‐extractable) and surface reaction with carbonates and/or Fe oxides (EDTA‐extractable) were the most likely retention mechanisms in the Oakville soil, although adsorption on cation exchange sites was observed for Cd and Zn at high loading rates.
Detection of Aspergillus Flavus and Aflatoxins in Cotton and Corn by Ultraviolet Fluorescence
Authors: Marsh Paul B. , Simpson Marion E. 
Published: July 2010

AbstractA 1954 report from the Beltsville Agricultural Research Center recorded the observation of a bright greenish‐yellow fluorescence or “BGYF” in raw cotton (Gossypium hirsutum L.) fiber and linked it to a previously unrecognized boll rot caused by Aspergillus flavus Link ex Fr.). Nine surveys employing the fluorescence as a detection device on U.S. cotton fiber produced during 1957 to 1981 showed this boll rot mostly in especially hot growing areas in southern California, Arizona, and Texas. The BGY‐fluorescing substance was produced in pure‐culture incubations of A. flavus on live never‐dried cotton fiber from unopened bolls. Evidence indicated it is caused by interaction between kojic acid from the fungus and peroxidase from the fiber. The fluorescence in field‐grown lint or seed‐fuzz is often accompanied by variable but generally high levels of A. flavus‐produced aflatoxins in the seeds bearing such fiber; presence of the fluorescence may be used as a presumptive test for aflatoxins. A 1968 report from Beltsville showed that the BGY fluorescence can also be generated by A. flavus in pure culture on live milk‐stage corn (Zea mays L.) kernels. Others later observed it in corn in the field and used it in corn‐aflatoxin investigations. A rapid presumptive test for aflatoxins in commercial corn, based on the BGY fluorescence, has been extensively used. Aspergillus flavus field infection and the BGY fluorescence in cotton and corn are influenced by the semithermophillic, semixerophytic, and wound‐parasitic characteristics of the fungus.
Nutrient Cycling in an Agricultural Watershed: I. Phreatic Movement
Authors: Lowrance R. Richard , Todd Robert L. , Asmussen Loris E. 
Published: July 2010

AbstractMuch of the runoff from agricultural fields in the southeastern Coastal Plain is carried to a stream channel system in a shallow phreatic aquifer. This subsurface runoff often passes through a band of riparian forest before becoming streamflow. It is hypothesized that the riparian ecosystem acts as a nutrient sink and reduces the concentrations and loads of nutrients in the shallow aquifer before the nutrients reach the stream channel. Concentrations and loads (kg/m2) of NO3‐N, NH4‐N, organic N, dissolved molybdate‐reactive P1 total P, Ca, Mg, K, Cl, and SO4‐S were measured in shallow phreatic wells at 37 locations on an agricultural watershed near Tifton, Ga. Total water volume moving off the watershed in subsurface flow was < 1% of streamflow with corresponding small amounts of nutrients. Nitrate‐N, Ca, and Mg had significantly higher concentrations in field wells than in forest or streamside wells. Concentrations of Cl were not reduced as water moved from field to forest. Processes within the riparian zone apparently converted primarily inorganic N from fields (76% NO3‐N, 6% NH4‐N, 18% organic N) into primarily organic N in streamside wells (10% NO3‐N, 14% NH4‐N, and 76% organic N). Concentration differences between field and forest wells indicated the riparian forest's ability to act as a sink for NO3‐N, Ca, Mg, K, and SO4‐S. Due to their role as nutrient sinks, riparian forests are important in maintaining stream water quality on agricultural watersheds.
Dissipation of Picloram in Storm Runoff
Authors: Mayeux H. S. , Richardson C. W. , Bovey R. W. , Burnett Earl , Merkle M. G. , Meyer R. E. 
Published: July 2010

AbstractThe extent of progressive decrease in concentration of the herbicide picloram (4‐amino‐3,5,6‐trichloropicolinic acid) in intermittent streamflow was determined during runoff‐producing storms. Maximum concentrations of picloram were 48 and 250 mg/m3 in initial runoff water leaving a sprayed 8‐ha area in 1978 and 1979. Concentration decreased with distance from the treated area in proportion to the size of adjacent, untreated watershed subunits, which contributed runoff water to streamflow. Picloram concentrations usually decreased with each successive runoff event; an exception occurred when unusually large quantities of runoff (8.7 cm) diluted concentrations to levels less than those observed in the succeeding event (1.4 cm runoff). About 6% of the applied picloram left the treated area during a period of 1 month when conditions were especially conducive to transport of the herbicice in surface runoff water.Rapid dilution of picloram was observed after direct introduction of the herbicide near the upper end of a larger stream during rising stage of flow. Maximum concentrations at 90, 1170, and 5400 m downstream from the point of introduction of 1270 g of picloram were 13 720, 470, and 5 mg/m3, respectively. The calculated quantity of picloram which was detected at the 5400‐m sampling point in streamflow was only 0.13% of that introduced. Mixing of water during streamflow and additions of uncontaminated water along the channel apparently reduced picloram concentration to below that detectable by gas chromatography.
Effect of Composted Municipal Sewage Sludge on Growth and Elemental Composition on White Pine and Hybrid Poplar
Authors: Mc Intosh M. S. , Foss J. E. , Wolf D. C. , Brandt K. R. , Darmody R. 
Published: July 2010

AbstractA field study was conducted to determine the benefits of land application of composted municipal sewage sludge to white pine (Pinus strobus L.) and hybrid poplar (Populus deltoides spp., P. angulata × P. trichocarpa) growth. Composted municipal sewage sludge was disked into a Chester silt loam (Typic Hapludult—fine loamy, mixed, mesic) at rates of 0, 150, and 300 dry Mg/ha. White pine seedlings and hybrid poplar cuttings were grown for 3 y on the plots which had been seeded with ‘Kentucky 31’ tall fescue (Festuca arundinacea Schreb.).White pine growth was not affected by the compost treatments. Poplar growth, however, increased as a result of the compost application. After 3 y, the average hybrid poplar heights were 233, 443, and 483 cm for the 0, 150, and 300 Mg/ha treatments, respectively. The height differences between the control and the compost‐amended plots were due to a faster growth rate and a longer growth period of the trees on the compost‐amended plots. Hybrid poplars grown on the compost‐amended soil had higher concentrations of N and K and a lower concentration of Zn in the leaves than the control. No consistent differences in elemental composition of the white pine needles were apparent.
The Effect of Chloride on the Availability of Cadmium
Authors: Bingham F. T. , Sposito Garrison , Strong J. E. 
Published: July 2010

AbstractCadmium complexes readily with chloride and sulfate; hence, increases in soil salinity may influence its availability. To evaluate the effect of chlorinity, a major component of soil salinity, the following study was undertaken. A greenhouse experiment was conducted with Swiss chard (Beta vulgaris Cicla) as the biological indicator of available Cd in soil at pH 4.0 and pH 7.0 and treated with three levels of Cd(NO3)2 combined with five levels of CaCl2. The soil solution was analyzed for cations and anions; these analyses were used as input data to chemically speciate Cd in the soil solution. Under these treatments, the total concentration of Cd in the soil solution, CdT, was found to exist principally as Cd2+ and CdCl+. Multiple regression analysis of leaf Cd data in relation to the concentration of CdT, Cd2+, and CdCl+ showed leaf Cd to be primarily a function of the Cd2+ concentration.
The Effect of Four Terrestrial Herbicides on the Productivity of Artificial Stream Algal Communities
Authors: Kosinski Robert J. , Merkle Morris G. 
Published: July 2010

AbstractArtificial streams containing algal communities derived from a spring and an agriculturally impacted stream were used to assess the effect of 0.1, 1, and 10 mg kg−1 atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine], trifluralin (α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine), MSMA (monosodium methanearsonate), and paraquat (1,1′‐dimethyl‐4,4′‐bipyridylium cation) on the productivity (photosynthesis and respiration) of stream algae. The importance of induced resistance to the herbicides was evaluated by comparing the responses of the spring and stream algae and by determining if allowing the streams to be colonized for 3 weeks in the presence of 0.01 mg kg−1 of the herbicide under test would modify response by selecting for a more resistant flora. Productivity was measured by open‐water oxygen methods for 3 weeks before and 3 weeks after herbicide injection. The communities derived from both the spring and the stream were dominated by diatoms, and responded similarly to trifluralin, atrazine, and MSMA, but had divergent responses to paraquat. Trifluralin had no effect on productivity. Photosynthesis was significantly depressed by 1 and 10 mg kg−1 atrazine and by 10 mg kg−1 MSMA, and there were indications of a slight inhibition by 0.01 mg kg−1 atrazine. Paraquat at 10 mg kg−1 had little effect on the spring‐derived communities but caused severe inhibition of the stream‐derived algae. There was little evidence that exposure to 0.01 mg kg−1 herbicide during colonization modified the response of the algae to any of the herbicides.
Algal Availability of Phosphorus in Suspended Stream Sediments of Varying Particle Size
Authors: Dorich R. A. , Nelson D. W. , Sommers L. E. 
Published: July 2010

AbstractThe availability of sediment P to algae was evaluated in several water stable aggregate‐size fractions of suspended stream sediments collected from an agricultural watershed in northeastern Indiana. Sediments were collected during a storm event, separated into the <2, 2 to 20, 20 to 53, 53 to 212, and > 212 µm size fractions, sterilized by γ irradiation, and incubated for 2 weeks with algae. Algal‐available P (Paa) was determined by measuring decreases in the NaOH‐ and HCl‐extractable inorganic P (Pi) fractions in sediment during the incubation period. The initial concentrations of P in the NaOH‐ and HCl‐extractable Pi fractions were not related to aggregate size. All aggregate‐size fractions had similar Paa concentrations. Nearly equal proportions of sediment Pi (avg 79%) and total P (avg 43%) in aggregate fractions were available to algae, possibly resulting from the similar distribution of primary particle sizes in all aggregate‐size fractions. More than 93% of Paa originated in the NaOH‐extractable P fraction. Samples that were affected by septic effluents tended to be higher in certain sediment P parameters (e.g., NaOH‐extractable Pi, total Pi, total P, and Paa concentrations) than samples containing suspended sediment derived from cropland. This study suggests that runoff models may not need to account for the detachment and transport of aggregate‐size classes to predict the movement of algal‐available P from cropland to surface waters.
The Influence of Mount St. Helens Ash on Wheat Growth and Phosphorus, Sulfur, Calcium, and Magnesium Uptake
Authors: Mahler R. L. , Mc Dole R. E. , Fredrickson M. K. 
Published: July 2010

AbstractConcern has been expressed that large amounts of volcanic ash from the 18 May 1980 eruption of Mount St. Helens may have created potential nutrition problems associated with wheat (Triticum aestivum L.) production in eastern Washington and northern Idaho to the extent that adjustments need to be made in soil test correlation data. The objectives of this study were to: (i) determine the effect of varying amounts of volcanic ash, either mixed into or placed on the surface of eight different agronomic soils of northern Idaho on total biomass production of wheat under greenhouse conditions, and (ii) to determine the effect of various soil‐ash mixtures on the nutrient concentration and total uptake of P, S, Ca, and Mg by wheat.Wheat was grown in eight different northern Idaho soils amended with differing levels of volcanic ash (0, 20, 35, 50, and 75%) in the greenhouse. Fertilizer N, P, and S were added to all treatments. Total plant biomass and P, S, Ca, and Mg concentrations and uptake were measured.Increasing amounts of volcanic ash gave no consistent effects on total wheat biomass. Based on biomass yields, soils were placed into four basic categories: (i) those where increasing levels of ash depressed plant growth, (ii) those where increasing ash levels stimulated biomass production, (iii) those where biomass yields were greatest with moderate levels of ash, and (iv) those where biomass yields were mixed.Plant S and P concentrations increased with increasing levels of ash for most soils. The ash did not fix appreciable amounts of P and increased plant‐available S. The ash also enhanced Ca and Mg uptake by plants. There is no evidence to suggest that high levels of ash (700 000 kg/ha) inhibit wheat biomass production. Consequently, there is no need for adjustments in soil test calibration data presently used for fertilizer recommendations for wheat.
Factors Affecting Phosphorus Losses from Cultivated Organic Soils
Authors: Cogger Craig , Duxbury John M. 
Published: July 2010

AbstractLeaching losses of P from organic soils can have a marked effect on water quality. Factors affecting leaching loss of P from cultivated organic soils in western New York State (Carlisle and Palms series) and ways to reduce these losses were investigated. The behavior of P in organic soils from eight sites with annual leaching losses ranging from < 1 to > 30 kg ha−1 y−1 was compared. Inorganic, organic, and total P; P extracted by soil test procedures; percent mineral matter; depth of organic horizons; leaching and adsorption of P; release of P during incubation; and total extractable Al and Fe were compared. A P balance was estimated using field and laboratory data, and cropping and fertilization history. Aluminum, iron, and adsorption equilibria were the best predictors of field leaching losses from these soils. While P loss from these soils is controlled by adsorption reactions, the best way to reduce the loss is through fertilizer management.
Field Performance of Conventional and Alternative Septic Systems in Wet Soils
Authors: Cogger C. G. , Carlile B. L. 
Published: July 2010

AbstractAn 18‐month field evaluation of 15 conventional and alternative septic systems was conducted to determine their effectiveness in soils with high water tables. The alternative designs included four low‐pressure pipe (LPP) systems, two soil replacement systems, and two pressure‐dosed mounds. Water tables were measured and groundwater samples collected monthly from shallow wells placed around each system. The water samples were analyzed for NO3−‐N, NH4+‐N, total Kjeldahl N, total P, and fecal coliform bacteria.All but one of the systems installed beneath the natural soil surface were saturated with groundwater for at least part of the year. Effluent treatment was poorest around systems that were continuously saturated with groundwater, with average levels of 7.3 mg/L NH4+‐N, 1.0 mg/L NO3−‐N, and 1700 fecal coliform most probable number (MPN)/L found in the groundwater in wells 1.5 m from these systems. Systems that were only seasonally saturated generally performed better, with average levels of 2.3 mg/L NH4+‐N, 2.0 mg/L NO3−‐N, and 560 fecal coliform MPN/L in the groundwater. Mean P levels in the groundwater exceeded 1 mg/L around six of the systems. The highest concentrations were associated with the most heavily loaded systems. Levels of all contaminants decreased with distance from the source. The greatest amount of lateral transport occurred when continuous saturation was accompanied by a steep groundwater gradient.Improved treatment was obtained using the LPP alternative, provided site and soil conditions were acceptable. Soil replacement systems did not improve treatment, while one mound failed due to overloading and abuse.
Shallow Groundwater Quality Beneath an Intensive Multiple‐Cropping System using Center Pivot Irrigation
Authors: Hubbard R. K. , Asmussen L. E. , Allison H. D. 
Published: July 2010

AbstractA study was conducted to compare shallow groundwater NO3‐N concentrations under intensive multiple cropping systems with those from under nearby nonagricultural sites. The intensive multiple cropping systems involved center pivot irrigation and sprinkler‐applied fertilizer. The study was conducted on a sandy Coastal Plain soil by weekly measurement and sampling of observation wells located under a center pivot area and at two forest sites. Nitrate‐N concentrations under the center pivot area ranged from < 1 mg/L to about 133 mg/L, with a mean of 20 mg/L (n = 360, SD = 19.5). In contrast, samples from the forest sites had NO3‐N concentrations ranging from < 0.1 mg/L to just over 1 mg/L. Mean NO3‐N concentrations under the center pivot area were found to vary seasonally according to cropping and hydrologic patterns such that the mean values for March–May, June–August, September–November, and December–February were 7, 21, 27, and 21 mg/L, respectively. The lower value for March–May indicated that winter rains leached most of the root zone NO3‐N beneath the wells by March, and that there was a 2 to 3 month lag between spring‐applied N and its appearance in shallow groundwater. The study raises concern about shallow groundwater quality under intense multiple cropping systems on sandy soils. Although studies in this physiographic area of the Coastal Plain have shown that relatively impermeable subsoil horizons cause shallow groundwater to flow laterally to the larger drainage networks, and that alluvial forests then remove most of the N, the results of this study imply that groundwater NO3‐N contamination could be a problem in other physiographic areas having sandy soils lacking such subsoil horizons.
Reduction of Radiostrontium Mobility in Acid Soils by Carbonate Treatment
Authors: Browman M. G. , Spalding B. P. 
Published: July 2010

AbstractDevelopment of chemical treatments to immobilize 90Sr in soil to prevent its leaching from radioactive waste disposed in shallow land burial sites is highly desirable. Six in situ carbonate‐precipitating treatments, varying the amounts of carbonate, alkaline earth cation (Ca or Ba as chlorides), and order of addition were examined for their ability to immobilize radiostrontium in laboratory soil columns. The Na2CO3‐followed by CaCl2‐treatment was most consistently successful at reducing the teachability of radiostrontium by 0.05M CaCl2 from three low organic matter‐acid soils, immobilizing as much as 53% of added radiostrontium. For the high organic matter‐slightly acid soil, Na2CO3 alone, without supplemental Ca or Ba, resulted in the best immobilization (39%); dissolution of soil organic matter and the alkalinity‐induced aggregate dispersion probably interfered with CaCO3 and/or BaCO3 precipitation. Success of the treatments is based primarily on their ability to generate, in situ, Ca(Sr,Mg)CO3 or Ba(Ca,Mg,Sr)CO3 precipitates that exchange radiostrontium very slowly with eluting Ca ions. Allied tests with 137Cs, which is commonly codisposed with 90Sr, indicated that the treatments described did not interfere with the natural tendency of the selected soils to fix 137Cs strongly.