bluuebunny/crossref_metadata_2025_split huggingface dataset:
Small Mammal Soil Burrowing as a Radionuclide Transport Vector at a Radioactive Waste Disposal Area in Southeastern Idaho
Authors: Arthur W. John , Markham O. Doyle 
Published: July 2010

AbstractDuring 1978 and 1979, small mammals excavated a total mass of 12,450 kg soil to the 36‐ha surface of a solid radioactive waste disposal area in southeastern Idaho. Elevated concentrations of 238Pu, 239,240Pu, and 241Am were detected in excavated and surface soils in the waste disposal area. The inventory of 66 µCi (90Sr, 137Cs, 238Pu, 239,240Pu, and 241Am) transported to the surface of the waste disposal area by small mammal excavations was significantly (P ≤0.05) greater than the 20 µCi estimated to occur in excavated soils at a control area where no radioactive waste was disposed. Seventy‐seven percent of the radioactivity in soil excavated to the surface of the waste disposal area by small mammals was 238Pu, 239,240Pu and 241Am; 98% of the radioactivity in excavated soil in the control area was 90Sr and 137Cs. Small mammal burrowing is a mode of transuranic radionuclide transport to the surface of the waste disposal area; however, the total amount of plutonium in excavated soils was only 0.05% of the amount estimated to occur in waste disposal area surface soils in 1974.
Decomposition of Sewage Sludge Compost in Soil: IV. Effect of Indigenous Salinity
Authors: Tester C. F. , Parr J. F. 
Published: July 2010

AbstractTo determine the effects of indigenous salinity on rates of compost decomposition and nitrogen transformations, a sewage sludge‐woodchip compost was leached with water. Leached and unleached composts were mixed with a loamy sand at rates of 0, 112, and 224 t ha−1 (dry wt), equivalent to 5 and 10% of the dry soil weight, and incubated at 25°C in a constant atmosphere of CO2‐ and NH3‐free air for 160 d. Rates of compost C decomposition and N mineralization were determined by monitoring an air stream for CO2 and NH3 evolution, and by measuring changes in the extractable organic and inorganic fractions of C and N in soil with time.The initial rate of CO2 evolution from the soil amended with leached compost lagged behind that of the soil amended with unleached compost. However, after 33 d of incubation, the leached compost treatments mineralized C at a faster rate, and after 160 d had evolved 14 and 32% more CO2 for the 112 and 224 t ha−1 rates, respectively. The initial lag may have resulted from partial removal of the more readily decomposable water‐soluble C by leaching. The total cumulative compost C evolved as CO2 from the unleached and leached compost mixtures after 160 d of incubation were about the same, i.e, 14% and 16%, respectively. However, the amounts of net N mineralized in the unleached and leached systems were greatly different. Approximately 14% of the N in the unleached compost had mineralized after 160 d, whereas the soil amended with leached compost exhibited a net immobilization of mineral N. These results indicate that salts and other compounds that are present in sewage sludge compost (water soluble) can inhibit compost decomposition when added to soil, and enhanced decomposition results in more immobilization of mineral N when these inhibitory compounds are removed by leaching.
Mineralization of Nitrogen in Sewage Sludges
Authors: Parker Chris F. , Sommers Lee E. 
Published: July 2010

AbstractMineralization of organic N is one of the principle factors governing the annual amount of sewage sludge applied to agricultural cropland. The mineralization of sludge organic N was studied in a Fincastle silt loam soil treated with 24 sewage sludges obtained from sewage treatment plants in several regions of the United States. The mineralization of sludge organic N was determined during a 16‐week incubation by analysis of inorganic N in (i) leachates from soil‐sludge‐sand mixtures and (ii) subsamples of unleached soil‐sludge mixtures. The nonleached procedure gave slightly higher estimates of mineralizable N in most sludges (average of 17 and 16% N mineralized by nonleached and leached procedures, respectively). The approximate amounts of mineralizable N in sludges expressed as a percentage of organic N were: raw and primary, 25%; waste‐activated, 40%; anaerobically digested, 15%; and composted, 8%. Inorganic N released from sludges by autoclaving in 0.01M CaCl2 or extracting with H2SO4 + KMnO4 was not highly correlated with N mineralization. Sludge organic N content was a reasonable predictor of mineralization of sludge N added to soils. The following regression equation was found to describe the mineralization of sludge organic N in soil: % of added sludge N mineralized = 6.37 × % sludge organic N + 4.63 (r = 0.77). To calculate the appropriate sludge application rates for agronomic crops, the percentage of sludge N mineralized during the initial cropping season should be related either to the process used for sludge treatment or to the concentration of organic N in the sludge.
Behavior of Chromium in Soils: V. Fate of Organically Complexed Cr(III) Added to Soil
Authors: James Bruce R. , Bartlett Richmond J. 
Published: July 2010

AbstractOrganically complexed Cr(III) added to soils may remain soluble, whereas the free Cr(III) metal ion would quickly become adsorbed and/or hydrolyzed and precipitated in the absence of soluble, complexing ligands. To separate these two phenomena, a laboratory procedure was developed to simulate the disposal of Cr(III)‐containing organic wastes in soils, and to investigate the solubilities of organic complexes of this heavy metal after addition to soil. The method involves adding Cr(NO3)3 to solutions of organic ligands adjusted to a pH between 3 and 8 to form inorganic hydrolyzed species and organic complexes at each pH. After measuring soluble Cr vs. pH, moist soil is added to bring the pH of each Cr‐ligand system to 6.5–7.0, thereby precipitating nncomplexed, inorganic Cr(III), and labile Cr(III)‐organic complexes. Subtracting Cr(VI) formed from total soluble Cr in the soil suspension gives a relative measure of organically complexed Cr(III) originally present in the aqueous systems at each pH.Citric acid, diethylenetriaminepentaacetic acid (DTPA), fulvic acids, and water‐soluble organic matter from air‐dried soil kept Cr(III) in solution above pH 5.5, and prevented its immediate removal by soil.Added Cr‐citrate remained soluble for at least 1 y in limed samples of an Ultic Hapludalf Ap horizon incubated at field capacity moisture. Because organic acids similar to those studied here may be found in sewage sludge, animal manures, and industrial wastewater, these results should be useful in predicting the fate of Cr(III) added to soils amended with such wastes.
Assessment of Heavy Metal Equilibria in Sewage Sludge‐Treated Soil
Authors: Behel David , Nelson Darrell W. , Sommers Lee E. 
Published: July 2010

AbstractThe objective of this research was to determine the effects of sewage sludge on speciation of metals in the soil solution. Sewage sludge was applied to an acid soil (pH ≈ 5) as a single treatment in 1971, or as annual treatments from 1971 through 1974 in amounts totaling from 50 to 800 t/ha. Surface soil samples were obtained from the plots in 1977 and the soil solutions were analyzed for Zn, Cd, Cu, Ni, Pb, Mn, Fe, Ca, Mg, Al, Na, K, PO4, SO4, Cl, pH, and organic C. The metal and ligand species in the soil solutions were calculated with the computer program GEOCHEM. Application of sludge increased soil solution concentrations of Zn, Mn, and Cd, while Cu, Ni, and Pb were present in most solutions at levels below the detection limits of the analytical methods used. Cadmium, zinc, and manganese in the soil solution appeared to exist predominately as the free ion. Complexation by inorganic and organic ligands ranged from 9 to 37%, 3 to 22%, and 3 to 31% of the total soluble Cd, Zn, and Mn, respectively, depending on the model used to represent metal interaction with soluble organic C. Cadmium was complexed with organic ligands to a greater extent than were zinc or manganese. Sulfate, phosphate, and chloride formed inorganic complexes with Cd, Zn, and Mn, but they constituted < 10% of the total metal present. Speciation of Zn and Cd into free metal ion and complexed forms was essentially the same in the soil solution, regardless of metal concentrations in solution and rate or frequency of sludge application. The solubility and DTPA extractability of Cd were increased to a greater extent by a single application of sludge than by multiple, annual additions.
The Effect of Soil Redox Potential and pH on the Reduction and Production of Nitrous Oxide
Authors: Smith C. J. , Wright M. F. , Patrick W. H. 
Published: July 2010

AbstractExperiments were conducted in controlled redox systems to assess the effects of pH and Eh on N2O reduction and production. Soil/water suspensions (ratio 1:3) were incubated at pH 5, 6, 7 and 8.5, and the redox potential (Eh) was controlled at selected potentials between −200 and +350 mV. Maximum N2O reduction was measured at pH 6 and 7. The critical Eh for N2O reduction and production occurred at +250 mV for pH 6, 7, and 8.5, and +300 mV for pH 5. Although N2O reduction began at a higher potential at pH 5, the rate of reduction was slightly lower under anoxic conditions at this pH. Alkaline conditions did not change the critical redox potential, but the rate of N2O reduction was lower. The data also demonstrate that soil can act as a sink for N2O under anoxic conditions.
Proxy Variables from Pollution Control
Authors: Daines David R. , Heady Earl O. 
Published: July 2010

AbstractWhere the level of pollution from one farm cannot be reliably measured or estimated, environmental policies may be difficult to formulate and enforce. For this situation, a policy approach is suggested, which focuses on variables other than direct output of pollution. The use of proxy variables is illustrated in an analysis of alternative policies for controlling agricultural soil loss in the United States. An interregional programming model of U.S. agriculture is used to analyze and compare the proxy variable approach to direct limits and taxes on gross soil loss, with soil management practices employed as proxy variables. In achieving targeted soil loss reductions, the soil management practice policy would be less costly to society than a direct limit of 12.5 t/ha of soil loss, but a tax on each t of soil loss would be the least costly approach, assuming that soil loss could be easily quantified.
Hybrid Differences in Estimation of Preharvest Occurrence of Bright Greenish‐Yellow Fluorescence and Aflatoxin in Corn
Authors: Lillehoj E. B. , Manwiller A. , Whitaker T. B. , Zuber M. S. 
Published: July 2010

AbstractReplicate, 200‐g kernel samples were acquired from 26 corn (Zea mays L.) hybrids of the 1980 South Carolina yield trials to study the interrelationships between moisture at harvest, bright greenish‐yellow (BGY) fluorescence, and aflatoxin concentrations. A modification of the BGY fluorescence detection method was developed to increase the accuracy of the rapid estimation of aflatoxin levels through a quantitative assessment of fluorescent material in finely ground samples. Ground samples from all of the test hybrids contained some BGY‐fluorescing particles, and > 90% of them contained aflatoxin. Although an elevated toxin level was only detected in kernels of a single hybrid, results based on the averages of hybrids in three hybrid maturity groups (short‐, mid‐, and full‐season) showed that kernels of the short‐season hybrids contained elevated levels of moisture, BGY fluorescence, and aflatoxin. Variation in moisture levels apparently was related to staggered planting dates of the three maturity groups to facilitate flowering at about the same time. Regression analyses showed significant associations between kernel moisture, BGY fluorescence, and aflatoxin. The results were considered in the context of development of rapid techniques for assessment of regional, preharvest aflatoxin contamination of corn.
Nitrogen‐15‐Labeled Nitrate Transport in a Soil with Fissured Shale Substratum
Authors: Rose C. W. , Chichester F. W. , Phillips I. 
Published: July 2010

AbstractPublished data on the fate of 15N‐labeled fertilizer applied to 4 Coshocton, Ohio, monolith lysimeters showed a series of declining NO3−‐N concentration maxima in the lysimeter percolate during 3 winter drainage periods subsequent to the single 336 kg/ha fertilizer application. A possible explanation of these concentration maxima as arising from the leaching of previously immobilized and subsequently mineralized N was quantitatively inadequate. In this study, we sought an alternative explanation of these observations.The lowest meter in the 2.44‐m deep monolith profile of Keene silt loam consisted of fissured shale bedrock, and analysis of mass conservation of 15N‐labeled inorganic N in the fissured layer provided an explanation of these observed annually periodic concentration maxima. Some of the calculated flux of labeled N into the top of the fissured layer was shown to be stored within the layer, and to reappear in subsequent annual winter drainage periods. Two possible mechanisms, which allowed such temporary storage, were identified: storage within the pore space of the crack system, and storage in micropores of the weathered rock by lateral diffusion from solution contained in the cracks.
Atmospheric Sulfur Deposition, Neutralization, and Ion Leaching in Two Deciduous Forest Ecosystems
Authors: Richter D. D. , Johnson D. W. , Todd D. E. 
Published: July 2010

AbstractIn the 1981 water year, bulk precipitation was primarily a solution of dilute H2SO4, and SO42‐ was the dominant anion in tbroughfall and soil leachates in two eastern Tennessee deciduous forests. Ecosystem inputs of SO42‐, which included dry deposition of forest canopies, may have been up to 40% greater than input estimates based on atmospheric deposition sampling in open areas. Volume‐weighted mean annual pH of bulk precipitation was 4.3; of throughfall 4.8; and of leachates from O2, A1, and B21 soil horizons about 6.0. At both sites, strong acids in precipitation were largely neutralized prior to rainwater's infiltration into mineral soil.Base cations that exchanged with H+ (hydrogen ions) in acid precipitation were almost entirely supplied by forest canopies and litter layers, and did not come directly from exchangeable mineral soil pools. Annual fluxes of HCO3− alkalinity from B21 horizons, about 0.42 and 0.51 kmol (−) ha−1 (keq ha−1) at the two sites, indicated that the natural H+ input from the partial ionization of H2CO3 was of similar magnitude to H+ input in bulk precipitation in 1981 [0.60 kmol(+)ha−1]. However, even in these infertile soils with low cation exchange capacities (CEC) [<7.2 cmol (NH4+) kg−1 (meq/100 g) in surface 50‐ or 80‐cm soil], exchangeable bases were more than two orders of magnitude greater than annual H+ input in bulk precipitation, and represented a substantial reserve for base cations in canopies and litter layers that exchanged with H+ in acid rain. Furthermore, inputs of H+ from acid precipitation were equal to about 0.4% of the base cations that are biologically cycling and immediately available in these ecosystems. Although poorly quantified, mineral weathering and deep rooting will supply, over time, substantial amounts of additional base cations for biologic cycling. Both soils are base‐poor Udults and classified as sensitive to acid rain, but the deposition, cycling, and soil data presented in this report indicate that leaching remains a process affecting cation reserves and soil development only over the very long term.
Nitrogen Loss From a High‐Fertility, Rotational Pasture Program
Authors: Owens L. B. , Van Keuren R. W. , Edwards W. M. 
Published: July 2010

AbstractA beef cattle‐pasturing system involving four rotationally grazed summer pastures (SG) and four pastures used rotationally for winter grazing/feeding (WGF) was studied on sloping upland watersheds in Ohio to determine effects of livestock management on N levels in water. Both summer and winter areas annually received 224 kg N/ha as NH4NO3 fertilizer. Surface runoff was collected automatically during runoff events, and subsurface flow was sampled from spring developments on a weekly basis. Although seasonal N concentration and transport in surface runoff tended to be greater in the area occupied by the cattle, N concentration and transport in runoff from the two areas were quite similar and did not significantly impair water quality, based on U.S. Public Health Standards. The NO3‐N concentration in the subsurface flow from the WGF area was higher than in the subsurface flow from the SG area. The NO3‐N concentration in the subsurface flow from both areas increased progressively throughout the study period, and reached levels as high as 18 mg/L. The subsurface flow provided the main pathway for N transport, with the surface transport being approximately 20 and 14% of the total N transport from the SG and WGF areas, respectively. The amount of sediment‐N transported was very small because of low soil loss.
PCB Partitioning in Sediment‐Water Systems: The Effect of Sediment Concentration
Authors: Horzempa L. M. , Di Toro D. M. 
Published: July 2010

AbstractThe effect of sediment concentration variations on polychlorinated biphenyl (PCB) sorption to natural lake sediment (Saginaw Bay, Mich.) and montmorillonite clay has been investigated. In studies utilizing tritiated 2,4,5,2′,4′,5′‐hexachlorobiphenyl (HCBP), partition coefficient values for adsorption isotherms (πa) were found to increase as sediment concentrations (m) were decreased from m = 1000 mg/L to m = 50 mg/L. HCBP adsorption to montmorillonite (m = 1000 mg/L, πa = 2900 L/kg; m = 50 mg/L, πa = 10 600 L/kg) appeared to be more sensitive to sediment concentration than did adsorption to the Saginaw Bay sediment (m = 1000 mg/L, πa = 9900 L/kg; m = 50 mg/L, πa = 17 100 L/kg). Evidence suggests that these variations are not the result of nonlinear isotherms. Although variations in solution chemical composition and kinetic effects were found to affect partitioning, neither factor appeared to adequately account for the magnitude of the observed sediment concentration effect. In experiments in which sediment concentrations were decreased (m = 1000 mg/L to 10 mg/L) while equilibrium aqueous HCBP concentrations were maintained at approximately constant levels, πa values for adsorption increased. The behavior was in conformity with the isotherm results. The observed behavior might be due to direct solid phase interactions between suspended particles. The occurrence of such interactions in natural waters could have potentially significant implications for efforts to predict sediment‐water PCB distributions.
Loss of Fall‐Applied 2,4‐D in Spring Runoff from a Small Agricultural Watershed
Authors: Nicholaichuk W. , Grover R. 
Published: July 2010

AbstractThe loss of 2,4‐D (2,4‐dichlorophenoxyacetic acid) applied in fall to wheat (Triticum aestivum L.) stubble on fields of Wood Mountain loam soil in semiarid southwestern Saskatchewan was measured in surface runoff from snow. The range of runoff volumes over the 6‐y period was representative of runoff observed over a 30‐y period at the same location.The loss of 2,4‐D was greater from the treated stubble compared with fallow, which served as the control. The average loss from the control of 1.3 g/ha gives an indication of background limits that can be expected if 2,4‐D is applied a year earlier.The 2,4‐D loss in snowmelt runoff is similar to losses in rainfall runoff from a severe storm soon after application.The 6‐y average loss was 4.1% of the amount applied (0.42 kg/ha). Correlation analysis showed the amount of loss to be a function of runoff.The average flow‐weighted mean concentration of 31 µg/L was well below the USEPA maximum permissible level of 100 µg/L, and slightly above the U.S. National Academy of Sciences and National Academy of Engineering objective of 20 µg/L for drinking‐water standards.
Yield Reduction of Soybean Due to Exposure to Sulfur Dioxide and Nitrogen Dioxide in Combination
Authors: Amundson Robert G. 
Published: July 2010

AbstractTwo soybean [Glycine max (L.) Merr.] cultivars, ‘Beeson’ and ‘Hark,’ were grown in the field and exposed to SO2 alone and in combination with NO2 in open‐top chambers supplied with charcoal‐filtered air to remove ambient O3. The exposures were for 56 midday hours during the pod‐filling period at concentrations of approximately 481 or 1335 µg m−3 SO2 with or without 115 µg m−3 NO2.3 Visible injury was produced only on plants exposed to the higher SO2 concentration, but senescence was accelerated in several treatments (i.e., control about the same as low SO2 < low SO2 + NO2 < high SO2 < high SO2 + NO2. The treatments of high SO2 alone reduced the yields of Hark 26% and Beeson 9%; NO2 with high SO2 reduced the yields 35% for Hark and 31% for Beeson. The lower concentration of SO2 alone reduced the yields of Hark 20% and Beeson 6%; the presence of NO2 at the lower SO2 concentration did not increase the effect on yield reduction in either cultivar. These results suggest that (in the absence of ambient O3) NO2 in combination with SO2 can reduce soybean yield more if the SO2 dose is above a threshold value.
Sewage Sludge Application to Calcareous Strip‐Mine Spoil: II. Effect on Spoil and Corn Cadmium, Copper, Nickel, and Zinc
Authors: Pietz R. I. , Peterson J. R. , Hinesly T. D. , Ziegler E. L. , Redborg K. E. , Lue‐Hing C. 
Published: July 2010

AbstractMetal concentrations in calcareous strip‐mine spoil and corn tissue (Zea mays L.) were examined in a long‐term field experiment using anaerobically digested sewage sludge. A total of 258 dry Mg ha−1 of sludge were applied to the highest sludge treatment from 1973 to 1977. Sewage sludge significantly increased the amounts of 0.1M HCl‐extractable Cd, Cu, Ni, and Zn in the spoil (0–15 cm). Spoil pH, 7.8, was not significantly affected by sludge applications, but yearly pH varied significantly.Cadmium and zinc concentrations in leaves and grain were significantly increased each year by sludge applications. In 1977, 28.7 µg Cd g−1 and 200 µg Zn g−1 were observed in leaves from the highest sludge treatment. Grain Ni concentrations were significantly increased after application of 258 Mg ha−1 of sludge. Significant (P ≤0.01) increases were observed for the total plant uptake of Cd and Zn from 1974 to 1977 and Ni in 1977. The order of metal enrichment for corn was Cd > Zn > Ni > Cu.Regression analyses showed that for Cd, Ni, and Zn the cumulative application in sludge and the 0.1M HCl‐extractable amounts from spoil were the most significant variables relating to the additive increases of these metals in corn tissue. The spoil mineral composition and pH appeared to be important in determining why Cd, Ni, and Zn availability did not decrease rapidly with time.
Performance of Goats and Lambs Fed Corn Silage Produced on Sludge‐Amended Soil
Authors: Dowdy R. H. , Bray B. J. , Goodrich R. D. , Marten G. C. , Pamp D. E. , Larson W. E. 
Published: July 2010

AbstractAn animal feeding study was conducted to measure the effects of feeding corn (Zea mays L.) silage grown on sludge‐amended vs. conventionally fertilized soil on the performance of dairy goats (Capra hircus) and market lambs (Ovis aries). Annual applications of 0, 15, 30, and 45 Mg/ha of sewage sludge (105–186 mg Cd/kg) produced corn silage that contained high levels of bioaccumulated Cd (5.26 mg/kg, year III). Zinc accumulated in the silage to a lesser extent, which resulted in undesirably low Zn/Cd ratios. In vitro digestible dry matter, cell wall constituents, acid detergent fiber and lignin, and silica accumulation were not affected by sludge fertilization.Dry matter intake, daily milk production, and feed efficiency of dairy goats were not affected by 3 y of continuous consumption of high Cd silage. Market lambs fed sludge‐fertilized corn silage tended (P < 0.05, year II) to have higher daily gains than did those fed control silage, whereas feed efficiency (kilograms gain ÷ kilograms feed) was not affected by sludge fertilization.