bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trace Metal Solubility in Soils and Waters Receiving Deicing Salts
Authors: Amrhein C. , Mosher P. A. , Strong J. E. , Pacheco P. G. 
Published: July 2010

AbstractLaboratory batch incubation studies were carried out to determine the effects of aerobic and anaerobic conditions on the solubility of trace metals in soils and waters treated with the deicing salts calcium magnesium acetate (CMA) and NaCl. The concentrations of trace metals were, in general, not controlled by equilibrium reactions but rather by the relative rates of several simultaneous and sequential reactions. In three soils from CA, NJ, and MI, and water treated with CMA the production of HCO3 from acetate decomposition initially increased the solution concentration of Pb and Zn as PbCO03 and ZnCO03. Eventually, supersaturation with respect to calcite occurred and the concentrations ofCu, Cd, Zn, V, and Cr decreased because of coprecipitation with the calcite. The precipitation of pyromorphite [Pb5(PO4)3Cl] was suspected based on elevated saturation indexes for this mineral. At low redox conditions, the solubilization of Fe‐ and Mn‐oxides increased the concentration of the trace metals that were adsorbed or coprecipitated with these phases. Supersaturation with respect to MnCO3, FeCO3, and VO(OH)2 occurred under low redox conditions. The rate constant for acetate decomposition under anaerobic conditions was 18 times lower than the rate constant for aerobic decomposition. This suggests that if a soil received a high loading of CMA, low O2 conditions could occur and CMA might leach to groundwater. There is evidence that the use of CMA could result in Pb and Zn mobilization as neutral ion pairs with carbonate.
Leaching of Nitrogen and Phosphorus from the Biomass of Three Cover Crop Species
Authors: Miller M. H. , Beauchamp E. G. , Lauzon J. D. 
Published: July 2010

AbstractCover crops, although they may reduce the leaching of NO3‐N to groundwater, may increase nutrient concentration in runoff because of biomass leaching during rainfall events. A simulated rainfall study was conducted in the laboratory to determine the effects of freezing alone and freezing plus drying treatments, loading rate, and rainfall intensity on the leaching of NH4‐N, NO3‐N, and inorganic P from the biomass of red clover (Trifolium pratense L.), annual ryegrass (Lolium multiflorum L.), and oilseed radish [Raphanus sativus (L.) var. oleifera Dc Metzg]. Concentration of P increased during early stages of leaching, then decreased slowly but remained greater than 50% of the maximum, even after the equivalent of 6.0 cm of simulated rainfall. Concentrations of NO3‐N were similar to P but changed less during leaching. Weighted mean concentrations of P ranged from less than 2.0 to more than 15 mg L−1. Concentrations were greatest with oilseed radish and least with red clover. Drying the sample in addition to freezing increased the P concentration, particularly in the initial leaching. About 30% of the biomass P was leached from oilseed radish and annual ryegrass, but only about 20% from red clover. Because oilseed radish had a greater biomass P concentration, the total P leached was much greater than for the other two species. Between 5 and 9% of the biomass N was leached as either NO3‐N or NH4‐N from ryegrass and red clover while over 10% was leached from oilseed radish. The results indicate that cover crop species differed markedly in their potential impact on nutrient concentration, particularly P, in runoff. Of the three cover crops tested, oilseed radish has the greatest potential impact and red clover the least.
Hycrest Crested Wheatgrass Accelerates the Degradation of Pentachlorophenol in Soil
Authors: Ferro Ari M. , Sims Ronald C. , Bugbee Bruce 
Published: July 2010

AbstractWe investigated the effects of vegetation on the fate of pentachlorophenol (PCP) in soil using a novel high‐flow sealed test system. Pentachlorophenol has been widely used as a wood preservative, and this highly toxic biocide contaminates soil and ground water at many sites. Although plants are known to accelerate the rates of degradation of certain soil contaminants, this approach has not been thoroughly investigated for PCP. The fate of [14C]PCP, added to soil at a concentration of 100 mg/kg, was compared in three unplanted and three planted systems. The plant used was Hycrest, a perennial, drought‐tolerant cultivar of crested wheatgrass [Agropyron desertorum (Fischer ex Link) Schultes]. The flow‐through test system allowed us to maintain a budget for 14C‐label as well as monitor mineralization (breakdown to 14CO2) and volatilization of the test compound in a 155‐d trial. In the implanted systems, an average of 88% of the total radiolabel remained in the soil and leachate and only 6% was mineralized. In the planted systems, 33% of the radiolabel remained in the soil plus leachate, 22% was mineralized, and 36% was associated with plant tissue (21% with the root fraction and 15% with shoots). Mineralization rates were 23.1 mg PCP mineralized kg−1 soil in 20 wk in the planted system, and for the implanted system 6.6 mg PCP kg−1 soil for the same time period. Similar amounts of volatile organic material were generated in the two systems (1.5%). Results indicated that establishing crested wheatgrass on PCP‐contaminated surface soils may accelerate the removal of the contaminant.
Occurrence of Atrazine and Degradates as Contaminants of Subsurface Drainage and Shallow Groundwater
Authors: Jayachandran K. , Steinheimer T. R. , Somasundaram L. , Moorman T. B. , Kanwar R. S. , Coats J. R. 
Published: July 2010

AbstractAtrazine is a commonly used herbicide in corn (Zea mays L.) growing areas of the USA. Because of its heavy usage, moderate persistence, and mobility in soil, monitoring of atrazine movement under field conditions is essential to assess its potential to contaminate groundwater. Concentrations of atrazine, deisopropylatrazine (DIA), and deethylatrazine (DEA) were measured in subsurface drainage and shallow groundwater beneath continuous, no‐till corn. Water samples were collected from the subsurface drain (tile) outlets and suction lysimeters in the growing seasons of 1990 and 1991, and analyzed for atrazine and two principle degradates using solid‐phase extraction and HPLC. In 1990, atrazine concentration ranged from 1.3 to 5.1 µg L−1 in tile‐drain water and from 0.5 to 20.5 µg L−1 in lysimeter water. In general, concentrations of parent and degradates in solution were atrazine > DEA > DIA. Lesser levels of atrazine were measured in 1991 from Plots 2 and 4; however, greater concentrations of atrazine (6.0–8.4 µg L−1) were measured from Plot 5. Throughout the two growing seasons, atrazine concentration in Plot 5 tile‐drain water was greater than that of Plots 2 and 4, suggesting a preferential movement of atrazine. Concentrations of DIA and DEA ranged from 0.1 to 2.2 and 0.9 to 3.2 µg L−1, respectively, indicating that the degradation products by themselves or in combination with parent atrazine can exceed the maximum contaminant level (mcl) of 3 µg L−1 even though atrazine by itself may be <3 µg L−1. The deethylatrazineto‐atrazine ratio (DAR) is an indicator of residence time in soil during transport of atrazine to groundwater. In Plots 2 and 4, DAR values for tile‐drain water ranged from 0.43 to 2.70 and 0.50 to 2.66, respectively. By comparison, a DAR of 0.38 to 0.60 was observed in Plot 5, suggesting less residence time in the soil.
The Role of Turfgrasses in Environmental Protection and Their Benefits to Humans
Authors: Beard James B , Green Robert L. 
Published: July 2010

AbstractTurfgrasses have been utilized by humans to enhance their environment for more than 10 centuries. The complexity and comprehensiveness of these environmental benefits that improve our quality‐of‐life are just now being quantitatively documented through research. Turfgrass benefits may be divided into (i) functional, (ii) recrcational, and (iii) aesthetic components. Specific functional benefits include: excellent soil erosion control and dust stabilization thereby protecting a vital soil resource; improved recharge and quality protection of groundwater, plus flood control; enhanced entrapment and biodegradation of synthetic organic compounds; soil improvement that includes CO2 conversion; accelerated restoration of disturbed soils; substantial urban heat dissipation‐temperature moderation; reduced noise, glare, and visual pollution problems; decreased noxious pests and allergy‐related pollens; safety in vehicle operation on roadsides and engine longevity on airfields; lowered fire hazard via open, green turfed firebreaks; and improved security of sensitive installations provided by high visibility zones. The recrcational benefits include a low‐cost surface for outdoor sport and leisure activities, enhanced physical health of participants, and a unique low‐cost cushion against personal impact injuries. The aesthetic benefits include enhanced beauty and attractiveness; a complimentary relationship to the total landscape ecosystem of flowers, shrubs and trees; improved mental health with a positive therapeutic impact, social harmony and stability; improved work productivity; and an overall better quality‐of‐life, especially in densely populated urban areas.
A Microcosm for Soil‐Atmosphere Gas Transfer Investigations
Authors: Ewing Lyn L. , Sheppard Marsha I. 
Published: July 2010

AbstractProposed disposal of high‐level nuclear wastes containing primarily inorganic 14C may provide a source of 14CO2 to the atmosphere. Laboratory experiments show that the loss of inorganic 14C is driven primarily by gaseous diffusion and is affected by the pH, porosity, temperature, moisture, and organic matter content of the soil. Two soil microcosms were designed to determine the degassing rate of volatile contaminants for the top 0.3 m of soil, the depth generally defined as the root zone in environmental assessment models. The performance of the system was evaluated in an investigation of the major factors affecting the transport of 14CO2 across the soft‐atmosphere boundary. These microcosms were used in a flow‐through system that allowed for manipulation and monitoring of parameters such as airflow, air moisture levels, air‐CO2 concentration and soil temperature and soil moisture with soils of different pH and organic matter content. The performance of the microcosms was assessed for 14CO2 using soil slurries and soil columns. The evolved 14CO2 was trapped in a series of NaOH gas traps, which were frequently sampled and analyzed. Profiles of soil moisture content, soil temperature and 14C activity could be established. This laboratory system was useful in estimating the rate at which 14CO2 is released from soil. Other traps could be tested for use with other soil contaminants.
Soil Tillage Effects on Ammonia Volatilization from Surface‐Applied or Injected Animal Slurry
Authors: Sommer S. G. , Ersbøll A. K. 
Published: July 2010

AbstractAmmonia (NH3) losses from cattle (Bos sp.) and pig (Sus scrofa) slurry applied to a harrowed and unworked soil were studied in seven field experiments from October 1990 to December 1991. In one experiment slurry was directly injected into the soil and hi six experiments slurry was surface‐applied. Ammonia losses were measured with a wind tunnel system. From directly injected slurry applied to a recently harrowed soil, NH3 losses were 30% of the losses from an unworked soil. Harrowing the soil immediately before surface application of the slurry reduced losses to less than 50% of the losses from an unworked soil. The accumulated NH3 loss from slurry applied in the field was described with a Michaelis‐Menten‐like equation, showing the NH3 loss reaction modeled adequately as a first‐order reaction. The effect of treatment, soil conditions, or environmental conditions on NH3 loss pattern from slurry applied in the field may therefore be treated statistically by comparing the parameters in the Michaelis‐Menten equation.
Photosynthetic and Growth Responses of Two Broad‐Leaf Tree Species to Irrigation with Municipal Landfill Leachate
Authors: Shrive S. C. , McBride R. A. , Gordon A. M. 
Published: July 2010

AbstractA study was undertaken to investigate leaf photosynthesis and stem growth responses of saplings of two broad‐leaf tree species to irrigation with municipal solid waste (MSW) leachate in a northern temperate climate at Ontario, Canada. The objective was to quantify plant stresses or changes in plant productivity that could be attributed to this low technology option for the treatment and disposal of groundwater contaminated by municipal refuse. Red maple (Acer rubrum L.) and hybrid poplar [Populus spp. nigra × maximowiczii (NM6)] were subjected to two consecutive seasons of leachate irrigation in a three factor, RCBD split‐plot field experiment. The three factors were irrigant type (MSW leachate, water), mode of application (spray, surface trickle, subsurface irrigation), and rate of application (3.5, 7.0, and 14.0 mm d−1). The main treatment plots in each of three blocks were split into subplots planted to different tree species. In the second irrigation season, the mean seasonal photosynthesis rates increased for irrigated saplings of both species relative to rain‐fed control saplings, irrespective of irrigant type. Mean seasonal photosynthesis rates for red maple increased with irrigant application rate, but were unaffected by irrigant type. Incremental stem diameter and height growth for this species were largely unaffected by the experimental treatments. Mean seasonal photosynthesis rates for hybrid poplar were unaffected by either irrigant type or application rate, but stem growth did increase significantly with leachate irrigation. The mode of irrigant application was not a significant factor in explaining plant response for either species. Direct exposure of leaves to potentially phytotoxic compounds in MSW leachate (volatile organics, and inorganics including metals) by spraying did not induce phytotoxic symptoms in the saplings. Irrigation of a MSW leachate of relatively high ionic strength can be carried out successfully on clay soils under Ontario climatic conditions without causing significant adverse effects on saplings of these tree species. Treatment and disposal of MSW leachates in tree plantations may offer a low technology, low cost option to municipalities.
Transport of Chlorsulfuron through Soil Columns
Authors: Veeh R. H. , Inskeep W. P. , Roe F. L. , Ferguson A. H. 
Published: July 2010

AbstractChlorsulfuron [2‐chloro‐N‐[[(4‐methoxy‐6‐methyl‐1,3,5‐triazin‐2‐yl)amino]carbonyl]‐benzenesulfonamide] is an anionic sulfonylurea herbicide with high soil persistence; consequently, there is interest in predicting its mobility hi agricultural soils. The objectives of this study were to determine the transport characteristics of chlorsulfuron in disturbed and undisturbed soil columns and evaluate the capabilities of LEACHM (Leaching Estimation and Chemistry Model) for predicting chlorsulfuron transport. Soil column experiments were conducted with two Montana soils (Amsterdam silt loam, file‐silty, mixed Typic Haploboroll, and Haverson silty clay loam, fine‐loamy, mixed (calcareous), mesic Ustic Torrifluvent) under unsaturated flow conditions. Unit gradient was established in all columns by balancing surface water input to outflow at the bottom of each column through a stainless steel porous plate connected to a vacuum chamber containing a fraction collector. A nonlinear least squares approach (CXTFIT) was used to fit breakthrough curves (BTCs) for Br− and 14C‐labeled chlorsulfuron using the linear equilibrium adsorption model (i.e., local equilibrium assumption or LEA model) and the bicontinuum model (i.e., nonequilibrium assumption). Observed Br− BTCs were best described by the bicontinuum model indicating physical nonequilibrium due to immobile water regions. Observed chlorsulfuron BTCs demonstrated both chemical and physical nonequilibrium during transport. The best fit to observed chlorsulfuron BTCs was obtained with the bicontinuum model using the dispersion coefficient optimized (i.e., fixed) from the Br− BTCs. LEACHM was used to generate predicted BTCs for chlorsulfuron utilizing independently measured or estimated soil physical parameters as input data. Predicted BTCs utilizing the Br−‐derived dispersion coefficient (D) and the bicontinuum model‐derived partition coefficient (Koc) did not adequately reflect observed BTCs primarily because the current version of LEACHM has no capability for accepting input parameters relating to nonequilibrium conditions. The D and Koc values for chlorsulfuron BTCs derived from the LEA model improved predictions; however, it is important to note that LEA‐derived D and Koc values for chlorsulfuron BTCs essentially compensate for nonequilibrium behavior. Finally, the experimentally determined chlorsulfuron BTCs confirmed the high mobility of this chemical at neutral soil pH values.
Seasonal Variation in Methane Emission from Stored Slurry and Solid Manures
Authors: Husted Søren 
Published: July 2010

AbstractMethane (CH4) is an important greenhouse gas and recent inventories have suggested that livestock manure makes a significant contribution to global CH4 emissions. The emission of CH4 from stored pig slurry, cattle slurry, pig solid manure, and cattle solid manure was followed during a 1‐yr period. Methane emission was determined by dynamic chambers. Emission rates followed a In‐normal distribution for all four manures, indicating large spatial and seasonal variations. Monthly geometric means for pig slurry, cattle slurry, pig solid manure, and cattle solid manure varied from 0.4 to 35.8, 0.0 to 34.5, 0.4 to 142.1, and 0.1 to 42.7 g CH4 m−3 d−1, respectively. For slurries CH4 emission rates increased significantly with storage temperatures, the Q10 value ranging from 3.4 to 5.7 depending on slurry type. The presence of a natural surface crust reduced CH4 emission from slurry by a factor of 11 to 12. Surface crust effects declined with increasing slurry temperature. Solid manures stored in dungheaps showed significant heat production. Pig solid manure temperatures were maintained at 30 to 60 °C throughout most of the year, while cattle solid manure temperatures were close to ambient levels until late spring, when heat production was initiated. Methanogenesis in solid manure also increased with increasing temperatures. For pig solid manure, CH4 emission rates peaked at 35 to 45 °C. No distinct temperature optimum could be detected for cattle solid manure, however, temperatures rarely exceeded 45 °C. The Q10 values for dungheaps ranged from 2.7 to 10.3 depending on manure type and Q10 temperature interval. Annual CH4 emissions from pig slurry, cattle slurry, pig solid manure, and cattle solid manure were estimated at 8.9, 15.5, 27.3, and 5.3 kg animal−1 yr−1, respectively. The annual emission of CH4 from stored animal manure in Denmark is estimated at 28 000 Mg yr−1.
Use of Mine Fills for Biological Renovation of Domestic Wastewater
Authors: Peterson C. E. , Reneau R. B. , Hagedorn C. 
Published: July 2010

AbstractDevelopment of Appalachian coal mining regions has been severely hampered by lack of domestic waste disposal technologies suited to fills. This research was conducted to evaluate the potential for biological renovation of domestic wastewater in fills produced from mining operations. Soil‐fill (a mixture of Jefferson, fine‐loamy, siliceous, mesic Typic Hapludult and Muskingom, fine‐loamy, mixed, mesic Typic Dystrochrept soils) and spoil‐fill (blasted rock material associated with the Taggart Marker and Low Splint Bench coal seams) were used in this study. Septic tank effluent (STE) and sand filter effluent (SFE) were applied to soilfill columns at four loading rates (0, 5.4, 10.8, and 21.6 L m−2 d−1) and spoil‐fill columns at one loading rate (21.6 L m−2 d−1) for a period of 20 wk. Fecal coliform numbers were reduced by 89 to 99% after passing SFE and STE through the fill columns. Coliform counts in effluent from the soil‐ and spoil‐fill columns were lower where SFE was applied as compared with STE. There were no significant differences between coliform counts in effluent from soil‐fill and spoil‐fill columns, although, there was a trend toward higher counts in effluent from the spoil‐fill columns. When soil‐fill columns were considered, coliforms were reduced more effectively (at the highest loading rate) in columns receiving SFE when compared with columns receiving STE. This study indicates that selected fills may be used when consideration is given to wastewater treatment and loading rate.
Boron Release from Fly Ash and its Uptake by Corn
Authors: Kukier U. , Sumner M. E. , Miller W. P. 
Published: July 2010

AbstractThe increasing costs of disposing of fly ash create an urgent need to find potential uses, one of which is land application to improve physical or chemical properties of soils. Because fly ash contains considerable amounts of B, which is often deficient in Southeastern soils, B release from fly ash and its uptake by corn (Zea mays L.) were investigated initially under greenhouse conditions. Two fly ashes from Georgia were tested as a source of B for corn grown on two soils of different texture (Cecil: clayey, kaolinitic, thermic Typic Kanhapludult, and Lakeland: thermic, coated Typic Quartzipsamment). Fresh (unweathered) fly ash was applied to Cecil soil at rates equal to 0.0, 3.1, 6.3, 12.5, 25, 50, and 100 g kg−1 soil, while the Lakeland soil being sandier received one‐half of these rates. Hot water extractable B content of fly ash increased with decreasing pH and both soils showed a linear relationship between fly ash rate and hot water extractable soil B. Soil pH was the main factor influencing B release from fly ash in soil‐fly ash systems (at given fly ash rate). Increased rates of B application in fly ash resulted in much higher tissue B contents and caused marked reductions in growth on both soils. Tissue B contents on the sandy Lakeland soil were higher at the same ash rate than on the heavier Cecil soil. Hot water extractable soil B is a good diagnostic criterion for evaluation of B availability to plants on fly ash amended soils.
Naturally Occurring Radionuclides in Agricultural Products: An Overview
Authors: Hanlon Edward A. 
Published: July 2010

AbstractLow levels of naturally occurring radionuclides exist in phosphatic clays, a by‐product of phosphatic mining and beneficiation processes. Concerns about these radionuclides entering the human food chain were an immediate research priority before the phosphatic clays could be reclaimed for intensive agricultural purposes. Efforts included the assembly of a large body of data from both soils and plants, part of which were produced by the Polk County (Florida) Mined Lands Agricultural Research/Demonstration Project (MLAR/DP). Additional detailed studies involving dairy and beef cattle (Bos taurus) were conducted by researchers working with the MLAR/DP. A national symposium was conducted in which data concerning the MLAR/DP work and other research projects also dealing with naturally occurring radionuclides in agriculture could be discussed. The symposium included invited review papers dealing with the identification of radionuclide geological origins, the geochemistry and movement of radionuclides within the environment, mechanisms of plant uptake, entry points into the food chain, and evaluation of dose and risk assessment to the consumer of low levels of radionuclides. The risk to human health of an individual obtaining 0.1 of his or her dietary intake from crops produced on phosphatic clays increased by 1 in 5 × 106/yr above a control individual consuming no food grown on phosphatic clays. Leaf tissues were found to be generally higher than fruit, grain, or root tissues. The natural range in radionuclide content among various food types was greater than the difference in radionuclides content between the same food produced on phosphatic clays vs. natural soils.