bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Distribution of Natural Radionuclides in Native Soils of Southern Saskatchewan, Canada
Authors: Kiss J. J. , de Jong E. , Bettany J. R. 
Published: July 2010

AbstractLittle information is available on the regional distribution of natural radionuclides in agricultural environments. Surface soil samples were collected from uncultivated, unfertilized sites in the agricultural area of Saskatchewan, Canada, and analyzed for 40K, and daughters of 238U and 232Th. Activities of 40K, 214Bi (238U daughter), and 208Tl (232Th daughter) were normally distributed with means of 480, 19, and 8 Bq kg−1, respectively. Overall, the activities of all three radionuclides decreased as soil texture became coarser, while distinct geographic areas with elevated levels were probably due to local parent material composition. Natural radionuclide levels were significantly correlated to one another and the average ratio of 214Bi/208Tl/40K in native, unfertilized Saskatchewan surface soils was 1:0.45:26.
Fluidized Bed Material Applied at Disposal Levels: Effects on an Apple Orchard
Authors: Korcak R. F. 
Published: July 2010

AbstractAtmospheric fluidized‐bed combustion represents an economical technology for the burning of high S fossil fuel. The combustion residue is a dry, alkaline material resulting from the burning of coal (or other fuel source) and limestone. Although the residue has been assessed as a limestone substitute, the current study examines the potential for disposing of relatively large quantities. Fluidized bed material (FBM) was applied at two rates to the surface area within the rows of an established apple (Malus domestica Borkh.) orchard containing four tree types. The rates were either 9.2 kg/m2 (low rate), 36 kg/m2 (high rate), or untreated control. The tree types used were ‘Spuree Rome’ on M9, ‘Redchief Delicious’ on M9 or M9/MM106, and ‘Sturdeespur Delicious’ on M9. Cumulative yields (kg/tree) were enhanced on three of four tree types over a period of 6 yr. A 15% reduction in yield was noted for Redchief Delicious on M9/MM106 stocks at the high FBM rate. No nutritional related problems were noted for this or any other of the tree types used. Part of the yield reduction noted was due to fruit size differences and/or differential sensitivity of this interstock/rootstock combination to the altered soil chemical properties. Generally, amended soil pH increased to about 7.0 for either rate, and electrical conductivity increased five fold at the high rate of FBM addition. Agricultural utilization of large volumes (up to 112 Mg/ha) of FBM, compared to past research where FBM was used as a lime substitute (2–6 mg/ha), appears to be a feasible alternative. However, rootstock selection for apple may need to consider the resultant changes in soil chemical status from FBM additions.
A Possible Mechanism for Manganese Phytotoxicity in Hawaii Soils Amended with a Low‐Manganese Sewage Sludge
Authors: Hue N. V. 
Published: July 2010

AbstractKnowledge of sludge‐soil interactions is essential for successful utilization of sludges on agricultural lands. To obtain such information, a greenhouse experiment was conducted on three Hawaii soils: a Typic Hydrandept, a Typic Chromustert, and a manganiferous Tropeptic Eutrustox. Each soil received four rates (0, 20, 40, and 80 g kg−1) of a low‐Mn municipal sludge. Lettuce (Lactuca saliva L.) was grown as a test crop. Manganese phytotoxicity unexpectedly occurred in all sludge‐amended treatments of the Oxisol and in the 80 g kg−1 rate of the Vertisol as indicated by reduced dry matter yields and by high plant‐Mn concentrations, which were all greater than 1000 mg Mn kg−1. Soil‐solution Mn also increased, reflecting the problem. In the manganiferous Oxisol, where Mn toxicity was most serious, soil‐solution Mn at transplanting significantly increased from 0.02 to 0.46, 5.57, and 7.26 mg Mn L−1 as sludge rate increased from 0 to 20, 40, and 80 g kg−1, despite a concurrent increase in soil pH from 5.43 to 6.78, 7.91, and 8.10. Four weeks later (at harvest), soluble Mn increased even more drastically from 0.01 in the untreated soil to 57, 640, and 1160 mg Mn L−1 in the 20, 40, and 80 g kg−1 sludge rate, even though soil pH levels of all sludge treatments were essentially equal (pH 5.0). These facts were virtually inexplainable by soil pH, redox conditions or the direct Mn contribution from the sludge. In contrast, Mn complexation by organic ligands (e.g., tartaric, pyruvic, protocatechuic acids), which were found in considerable quantities in the soil solutions of sludge‐amended soils, accounted for 76 to 99% of the soluble Mn, and adequately explained the high and phytotoxic levels of Mn in soil solutions.
Volatilization of Organic Chemicals from Soil as Related to Their Henry's Law Constants
Authors: Spencer W. F. , Cliath M. M. , Jury W. A. , Zhang Lian‐Zhong 
Published: July 2010

AbstractThe output from a pesticide screening model indicated that chemicals with low Henry's Law constants (KH) will tend to accumulate at the soil surface when water is evaporating, resulting in an increased volatilization with time. Volatilization losses and surface distributions of two pesticides with widely differing KH, were measured to test the predictions of the screening model, particularly with respect to the importance of KH in controlling relative volatilization and vapor behavior. Volatilization of prometon (2,4‐bis(isopropylamino)‐6‐methoxy‐s‐triazine], a Category III compound with low KH, increased with time with water evaporating and prometon accumulated at the soil surface. Volatilization of lindane (gamma isomer of 1,2,3,4,5,6‐hexachloro‐cyclohexane), a Category I compound with high KH, decreased with time with or without water evaporating and did not accumulate at the surface with water evaporating. The experimental data confirmed the model predictions that volatilization of chemicals with low KH is controlled by the air‐boundary layer above the soil surface, whereas control of volatilization of Category I chemicals with high KH is within the soil. Accumulation and increased volatilization of compounds with low KH are controlled by boundary layer thickness and water evaporation rate as well as KH. The phenomena of organic chemicals with low KH accumulating at the soil surface following convective movement in evaporating water could greatly enhance their volatilization and increase their availability for photolysis and runoff into surface waters. Sufficient accumulation can occur that changes in adsorption coefficients with concentration must be taken into account in modeling their volatilization.
Radionuclides in Louisiana Soils
Authors: Meriwether John R. , Beck James N. , Keeley Dean F. , Langley M. Pamela , Thompson Ronald H. , Young John C. 
Published: July 2010

AbstractConcentrations of natural and man‐made radionuclides including 40K, 137Cs, and some of the decay products of 238U and 232Th were determined in soil. Samples were taken at a set of permanent radiation monitoring stations and from random points across the state of Louisiana. The concentrations of the radionuclides were found to be correlated with soil suborder: the lowest values found in the Udults of the northern portion of the state and the highest concentrations found in the Aquepts of the flood plains and the Hemists of the coastal marshes, suggesting that processes such as weathering, transport of solids, and dissolution may be fractionating these elements into soils of water environments. The concentration of K was found to vary from 3180 to 24 900 mg kg−1; U varied from 2.3 to 4.0 mg kg−1; and Th from 8.0 to 24.1 mg kg−1. Cesium‐137, the fission product, was found only in the top 15 to 20 cm of the soils with no statistically significant aerial distribution across Louisiana.
Trickle Irrigation of Cotton with Treated Sewage Effluent
Authors: Papadopoulos I. , Stylianou Y. 
Published: July 2010

AbstractThe objectives of this field study, conducted in 1984 through 1986, were to assess the long‐term effects of applying treated municipal effluent (ECw = 2.6 dS m −1; SAR = 12.0) by trickle irrigation on soil N fertility, soil salinity, and yield of cotton (Gossypium hirsutum L. cv. Sindos 1980) under semiarid conditions. Secondary treated effluent was compared with borehole water. Both waters were supplemented with 0, 30, 60, and 90 mg N L−1. The N concentration in the effluent was about 30 mg L−1 during the 3 yr of experimentation. The residual soil NO3‐N and the NO3‐N concentrations in laminae and petioles were in general greater in the effluent‐irrigated crops. With both waters, excessive salt buildup occurred at the periphery of the wetting front. Sodium adsorption ratio (SAR) was reduced beneath the dripper in the surface 15 and 30 cm depth with borehole water and effluent, respectively, but below this depth the reverse occurred. Under the conditions of soil type, climate, and borehole water and effluent qualities used during this experiment, effluent was generally superior to borehole water, particularly at the lower N levels in increasing yields. The seedcotton yield obtained in the first season was significantly greater in the effluent irrigated treatments supplemented with N up to 60 mg L−1; in 1985 and 1986 seasons, yield with treated effluent was significantly higher in comparison with borehole water when additional N of 30 mg L−1 was applied. It can be concluded that municipal‐treated effluent containing 30 mg N L−1 can be used effectively by trickle irrigation systems as a source of irrigation water and N, and with appropriate N and water management, ecological hazards due to NO3‐N are minimized, and salinity and sodicity are maintained at acceptable levels for cotton.
Elution of Selenium from Contaminated Evaporation Pond Sediments
Authors: Alemi M. H. , Goldhamer D. A. , Grismer M. E. , Nielsen D. R. 
Published: July 2010

AbstractSelenium‐contaminated sediments were collected from evaporation ponds at the Kesterson National Wildlife Refuse in California. Columns of undisturbed, freeze‐dried, and air‐dried sediments were each leached with deionized water, California aqueduct water, and saline water. Total Se and inorganic Se were measured in the effluent. Following leaching, the sediment cores were sectioned, extracts were prepared using deionized water, and analyzed for total Se, inorganic Se, and selenite using fluorimetric techniques. Selenium remained immobile in the undisturbed sediments, but freeze‐ and air‐drying increased Se mobility. The maximum concentrations of total Se in the effluent from undisturbed, freeze‐dried, and air‐dried sediments were 32, 7600, and 232 650 nmol L−1, respectively. Microbial activity played an important role in the reduction of Se to immobile and volatile forms. Se recovered in the effluent and from water extraction of the sediments following leaching was highest for deionized water and least for aqueduct water under nonsterilized conditions. The composition of solution did not significantly influence the leaching of Se under sterilized conditions. Introducing Se to previously leached sediments resulted in an increase in water‐extractable Se, particularly near the surface. However, when the concentration of added Se was high (31.70 µmol L−1 in this study), the increase in water‐extractable Se also occurred at greater depths in the sediments.
A Case Study of the Effects of Oil Shale Operations on Surface and Groundwater Quality: I. Sources of Contamination and Hydrologic Controls on Water Composition
Authors: Garland T. R. , Wildung R. E. , Zachara J. M. 
Published: July 2010

AbstractA study was undertaken to determine the effects of the disposal and leaching of retorted shale and other wastes on the water quality of a local drainage at the Rifle Oil Shale Project. An estimated 200 000 t of retorted shale and 146 000 t of raw shale were disposed during a 35‐yr period at the site, located near Anvil Points, CO. Previous studies suggested that operations did not impact the site. However, this investigation revealed elevated salt concentrations in wells, seeps, and surface waters downstream of the site. This investigation included a detailed survey of the potential contaminant and water sources at the site and measurement of inorganic and organic constituents in surface and groundwaters as a function of proximity to the disposal areas and hydrologic factors in the watershed. Sources of the salts were unlined evaporation ponds, subsoils leached by waters from leaking sanitary water system, and leachates from the raw and retorted shale piles, which also serve as artificial water recharge areas. These sources had not been previously detected because prior investigations did not take into account distinct spatial and diurnal fluctuations in flow rate in the surface waters, which alternately diluted and concentrated contaminants contributed by groundwater recharge. Fluctuations in flow rate were shown to result from daily meteorological effects on snowmelt (December–March) and transpiration by vegetation in the watershed (June–December). Detailed assessments of these factors are required before the long‐term effects of an oil shale industry on the Colorado River Basin can be determined.
A Case Study of the Effects of Oil Shale Operations on Surface and Groundwater Quality: II. Major Inorganic Ions
Authors: Garland T. R. , Zachara J. M. , Wildung R. E. 
Published: July 2010

AbstractThe distribution of the major inorganic ions in surface and groundwater, as related to substrata and hydrologic phenomena, was determined in a semiarid watershed representing an important area of oil shale development in northwestern Colorado. Surface and alluvial groundwaters were analyzed with time over a period of 1 yr, both upstream and downstream of an unengineered oil shale disposal site. These observations provided unique insight into the chemical and hydrologic controls on the composition of major ions in ground and surface waters. The primary dissolved species in the surface and groundwaters above and below the disposal site were Na +, Mg2+, Ca2+, SO2−4, and HCO−3. Increases in total salts in alluvial groundwaters below the disposal site were due primarily to Na + and SO2−4. Groundwaters above the disposal site were found to be in near equilibrium with calcite and dolomite; waters below the site were also in equilibrium with gypsum. Concentrations of the other ions measured all increased below the site, but elements lacking major solubility controls in calcareous soil and subsoil, i.e., K++, Li++, CL−, and NO−3, were most elevated. These solutes decreased in concentration down‐gradient from the waste disposal area, but different phenomena controlled their behavior. Concentrations of HCO−3 in alluvial groundwater fluctuated seasonally (+20%), reflecting a combination of biological (microbial and root respiration) and mineral solubility (e.g., CaCO3) controls. Although the primary source of N to groundwater was NH+4‐laden waste water, NO3 − constituted the major N species measured as a result of nitrification in the relatively aerobic groundwater system. Macroions indicative of the influence of the waste disposal site on surface water quality were CL−, K++, and Li++. Lithium could serve as a sensitive indicator of the presence of retorted shale leachate.
Dynamics of Carbon, Nitrogen, and Phosphorus Cycling in a Sawgrass Tidal Marsh with Special Reference to the Aboveground Primary Production
Authors: Hsieh Y. P. 
Published: July 2010

AbstractThe litter‐bag method was used to assess the disappearance rates of organic C, N, and P from the plant detritus of a sawgrass (Cladium jamaicense Crantz) tidal marsh in North Florida. A steady‐state kinetic model was used to simulate the effects of C, N, and P cycling dynamics on the quantity and quality of soil organic matter in the marsh. Four basic parameters were required for the model, namely, (i) net annual primary production of C, N, and P, (ii) soil organic C, N, and P in the biologically active layer, (iii) disappearance rate of dead standing crop, and (iv) disappearance rates of sawgrass C, N, and P from the litter‐bag. The decomposition of sawgrass C, N, and P can be described by a two‐component model through which a labile fraction and a refractory fraction of the primary production are defined. The rate constants of the labile fraction are one to two orders of magnitude greater than those of the refractory fraction. Simulation study indicated that the time required for soil C, N, and P to reach the steady state were 30, 60, and 70 yr, respectively. The simulation also indicated that the C/N ratio of the soil organic matter changed most significantly in the first 10 yr of the marsh development, whereas the N/P ratio remained relatively the same during the same period of time. The C/N and N/P ratios and the mean fraction remaining of soil organic matter all approach their respective steady‐state values, which are 23, 13, and 0.47, respectively. The observed C/N and N/P ratios of the soil organic matter were 21 and 13, respectively. The calculated labile fractions of the sawgrass were 0.34, 0.205, and 0.488 for organic C, N, and P, respectively. The mean retention time of C, N, and P in the labile fraction was 8.5 months. The MRTs of the refractory fractions were 10, 29, and 33 yr for C, N, and P, respectively. The bulk of the soil organic matter consists almost entirely of the refractory fraction of the primary production. According to the simulation, decomposition rate constants of plant detritus were the most significant and sensitive parameters that determine the quantity and quality of the soil organic matter. The annual N and P cycling rates between the aboveground sawgrass and the soil were estimated to be 18.8 g/m2 and 1.9 g/m2, respectively.
Use and Misuse of the DTPA Soil Test
Authors: O'Connor G. A. 
Published: July 2010

AbstractThe DTPA soil test was originally developed to identify near‐neutral and calcareous soils with insufficient available Zn, Fe, Mn, and Cu for maximum yields of crops. It apparently draws on labile pools it was designed to extract and correlates well with plant micronutrient concentrations when the soil metal levels are neither too high nor too low. The soil test reliably reflects metal loadings to soils supplied in a variety of forms, but may not reliably predict plant metal concentrations expected from increased soil loadings. The successes or failures of the soil test noted in the literature can be explained as correct uses or misuses, respectively, of the test. The soil test is best used to identify micronutrient deficient, near‐neutral, and calcareous soils. Whenever one strays from the original design of the test, one should be aware of the possible consequences and pass that awareness on to others.
Groundwater and Soil Leachate Inorganic Nitrogen in a Wisconsin Red Pine Plantation Amended with Paper Industry Sludge
Authors: Bockheim J. G. , Benzel T. C. , Lu Rui‐Lin , Thiel D. A. 
Published: July 2010

AbstractIn late August 1984, a 2.5:1 primary/secondary paper industry sludge was applied to a row‐thinned, 27‐yr‐old red pine (Pinus resinosa Ait.) plantation in central Wisconsin at levels of 32, 63, and 94 dry Mg ha−1 (550, 1120, and 1670 kg N ha−1, respectively). There were positive treatment effects on NO3‐N and NH4‐N in soil leachates and groundwater, but because of sample variability, few of these differences were significant at the p ≤ 0.05 level. Nitrate‐N concentrations exceeded 10 mg L−1 for all treatments at the 10‐, 45‐, and 75‐cm depths, but the potability standard was exceeded at the 165‐cm depth and in groundwater only on plots receiving the medium and heavy applications. Nitrate‐N concentrations generally were greater in the upper 30 cm of the saturated zone than at 60 and 90 cm, suggesting a lack of vertical mixing. Whereas the maximum NO3‐N concentration decreased with depth, the time required for NO3‐N concentrations to exceed 10 mg L−1 for a given treatment and the duration of the period when NO3‐N concentrations exceeded 10 mg L−1 increased with depth. The seasonal trends in inorganic N concentrations in soil water collected at the 10‐ and 45‐cm depths could be explained on the basis of N mineralization as derived from field incubation studies. A regression equation relating maximum NO3‐N in groundwater to N content of the applied sludge indicates that little groundwater degradation will occur at depths of ≥ 5.2 m in central Wisconsin when the N application to pole‐sized red pine is ≤800 kg ha−1 (≤46 dry Mg sludge ha−1).
2,3,7,8‐Tetrachlorodibenzo‐P‐dioxin: Aspects of Its Important Properties and Its Potential Biodegradation in Soils
Authors: Arthur Mickey F. , Frea James I. 
Published: July 2010

Abstract2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) is a persistent xenobiotic compound that has become widely dispersed in the environment. In laboratory animals, TCDD is acutely and chronically toxic, and is a carcinogen, mutagen, and teratogen. In humans, epidemiological studies of residents from Times Beach, MO, and Seveso, Italy, have failed to document significant TCDD‐induced health effects. The environmental persistence of TCDD is due in part to its resistance to microbial attack. The factors responsible for microbial recalcitrance of pesticides are reviewed and related to the recalcitrance of TCDD. It is suggested that a major factor limiting TCDD degradation in the environment is its unavailability to the indigenous microflora. The possibility to decontaminate soils by mobilizing TCDD for attack by soil microorganisms is discussed.
Denitrification below the Crop Rooting Zone as Influenced by Surface Tillage
Authors: Parkin T. B. , Meisinger J. J. 
Published: July 2010

AbstractIn recent years, there has been increased concern over pollution of groundwater by NO3−, yet little is known about microbial N transformations below the crop rooting zone. This study investigated the importance of microbial denitrification below the crop rooting zone of conventional and no‐till corn plots. The soil was a well‐drained Matapeake silt loam located in the Atlantic Coastal Plain. Plots were sampled in 30‐ and 60‐cm depth increments down to the water table, which occurred at ca. 420 cm. Total viable bacteria and numbers of denitrifying bacteria decreased exponentially with increasing soil depth down to 150 cm. From 180 cm to the top of the water table total bacterial numbers were very low (< 100 organisms/gram). No CO2 production activity was observed below the 180‐cm depth in unamended soil incubated aerobically at 25°C for 24 h. Anaerobic incubations with added NO3− and glucose showed no denitrifying activity below the 180‐cm depth. These results indicate that C levels below the rooting zone in this well‐drained, low organic matter soil are too low to support anaerobic conditions necessary for denitrification or to sustain a microbial population. Therefore, denitrification is not a mechanism of significant NO3− loss below the crop rooting zone at this location. Surface tillage practices had little influence on microbial activity below the root‐zone.