bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrification in Sludge‐Amended Michigan Forest Soils
Authors: Burton Andrew J. , Hart James B. , Urie Dean H. 
Published: July 2010

AbstractNet nitrification following liquid sludge application to four Michigan forest types was studied by aerobically incubating intact cores containing the forest floor and upper 10 cm of mineral soil. Significant net nitrification occurred in cores receiving surface applications of anaerobically digested municipal sludge (22.3 g N m−2). Core NO3‐N contents at 8 wk were 4.7, 5.3, 4.9, and 2.0 g m−2 for aspen (Populus spp.), northern hardwoods, oak (Quercus spp.), and pine (Pinus spp.) forest types, respectively. Net nitrification did not occur during 8‐wk incubations of untreated control cores or cores receiving surface applications of sludge sterilized by freeze‐drying (24.5 g N m−2) or liming (25.7 g N m−2), suggesting that the nitrifiers responsible for net nitrification in cores receiving the anaerobically digested sludge were added with the sludge. Nitrate content at 8 wk in cores from an oak field site receiving anaerobically digested sludge (43.0 g N m−2) 33 mo prior to incubation was 72% of that in oak site soil cores treated immediately prior to incubation (22.3 kg N m−2), indicating that nitrifying populations introduced with sludge 33 mo prior were still viable. Nitrate content at 8 wk in oak cores was 77% lower when sludge was incorporated. Nitrate contents in incubated soil cores could not be used to directly predict NO3 concentrations in soil leachate and groundwater beneath sludge‐treated plots at the four field sites. Results indicate that nitrification and potential for NO3 leaching following sludge application to acid forest soils are influenced by sludge type, forest type, and history of prior sludge applications.
Definition of Adverse Effects for the Purpose of Establishing Secondary National Ambient Air Quality Standards
Authors: Tingey David T. , Hodsett William E. , Henderson Sandra 
Published: July 2010

AbstractUnder the Clean Air Act, the USEPA establishes ambient air quality standards to protect public welfare from known or anticipated adverse effects from criteria air pollutants. Although adversity is simply defined (i.e., opposed to one's interest; harmful), its determination is fraught with difficulties. The definition depends on one's view point; society has established that some effects are more serious than others. There is a view that ecological effects are adverse only if they can be expressed in economic terms. This leads to the conclusion that mitigative actions need not be taken unless the costs of the action are offset by sufficient benefits. Adverse effects, however, should be viewed in a broader societal content, i.e., the total benefits from ecological systems.
The Removal of Barium Ion from Solution using Datura innoxia Mill. Suspension Culture Cells
Authors: Jackson Paul J. , Torres Agapito P. , Delhaize Emmanuel , Pack Elizabeth , Bolender Sarah L. 
Published: July 2010

AbstractPlant suspension culture cells derived from Datura innoxia (Mill.) anthers rapidly remove Ba2+ from solution. Free Ba2+ is removed as a result of a strong interaction with a component of the cell wall. Binding to this component occurs over a wide range of pH and salt concentrations and does not require active metabolism. Cells will remove Ba2+ from nutrient media or from waste solutions that cannot support cell growth. Implications for the use of plant cell suspension cultures to remove this and other toxic ions from industrial effluent are discussed.
Nutrient and Sediment Losses from Turfgrass
Authors: Gross C.M. , Angle J.S. , Welterlen M.S. 
Published: July 2010

AbstractThe contribution of turfgrass fertilizer to surface and groundwater pollution is not well documented. Two studies, at separate locations, were therefore initiated to examine losses of nutrients and sediment via leaching and runoff from turfgrass. Treatments included fertilizer applied in a liquid and granular form and an unfertilized control. Sodded tall fescue (Festuca arundinacea Schreb.)/Kentucky bluegrass (Poa pratensis L.) plots were fertilized at a rate of 220 kg N ha−1 yr−1 in metered applications of urea. Runoff was collected and analyzed for volume, suspended and soluble solids, NH4‐N, NO3‐N, total N, PO4‐P, total soluble P, and total P. Runoff losses of sediment and all nutrients were extremely low. Runoff losses of total N were significantly (P ≤ 0.05) higher when comparing the liquid and granular treatments to the control, although there was no difference between fertilizer treatments. Losses for all forms of P and sediment did not significantly differ with regard to treatment. Soil percolate (0.75 m depth) was collected monthly from the various treatments. Percolate NO3‐N concentrations from the liquid and granular treatments did not differ significantly, although both were significantly higher than the untreated control. Soil cores (2.1 m depth) were collected every spring and fall in 0.30‐m increments. Nitrate‐N concentrations generally decreased with depth; however, the granular treatment exhibited a higher soil NO3‐N concentration than either the liquid or control treatments. These results indicate that when compared with agronomic row crops, nutrient and sediment losses from turf via runoff, and leaching are very low.
Long‐Term Swine Lagoon Effluent Applications on ‘Coastal’ Bermudagrass: II. Effect on Nutrient Accumulation in Soil
Authors: King Larry D. , Burns J. C. , Westerman P. W. 
Published: July 2010

AbstractApplication of effluent from animal manure lagoons to cropland is an effective method of utilizing the nutrients in the effluent and minimizing groundwater and surface‐water pollution. The objective of this study was to determine the effect of land application of effluent from a swine (Sus scrofa domenticus) manure lagoon on selected soil chemical properties at the end of an 11‐yr study. Effluent was applied at rates to supply approximately 335, 670, and 1340 kg of N ha−1 yr−1 to ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.) on a Paleudult soil from 1973 through 1983. Soil cores taken to a depth of 210 cm were analyzed for H2O‐extractable NO3‐N and Mehlich 1‐extractable P and cations. Nitrate‐N concentrations (1‐5 mg kg−1) with the two lower rates were similar to concentrations where no effluent was applied. At the high effluent rate, NO3‐N concentrations were elevated, particularly in the subsoil, and 540 kg NO3‐N ha−1 was present in the profile. Phosphorus increased with loading rate and at the high rate, P concentrations (450 mg kg−1) in the 0‐ to 15‐cm zone was 10 times the level above which no response to P fertilization would be expected. Potassium concentration increased with loading rate throughout the profile. Magnesium accumulation was inversely related to effluent loading rate in the 0‐ to 15‐cm zone, but accumulation in the subsoil was directly related to loading rate. Comparison of profile nutrient distributions at the high rate for Years 6 and 11 showed no appreciable accumulation of NO3‐N during the period. Accumulation of other nutrients during this 5‐yr period was P, 210%; K, 200%; Ca, 140%; Mg, 60%; and Na, 10% as compared with Year 6. Soil pH was decreased by the high effluent rate but did increase from 4.2 at Year 6 to 5.0 at Year 11 due to the increased rate of application of basic cations during that period. The high rate poses a groundwater pollution hazard because of the large quantity of NO3‐N present in the profile. In previous years, appreciable NO3‐N was also present at the medium rate, but NO3‐N was low at this rate in Year 11. The high P concentrations in the surface soil increase the potential for runoff transport of P, which might pose a surface‐water pollution problem.
Application of Ecological Classification to Environmental Effects Analysis
Authors: Jensen Mark E. , McNicoll Cecilia H. , Prather Martin 
Published: July 2010

AbstractThe Northern Region of the USDA‐FS has developed an efficient and consistent method for assessing environmental effects of management practices on the soil and vegetation resources it administrates. Ecological classification and analysis constitute the basis of this method. Because many of the management activities in the region alter the present vegetation of a site (and consequently its values for a variety of resource uses) an understanding of plant succession relationships is critical to proper effects analysis. The ecological approach to effects analysis presented in this paper has proven effective in the Northern Region and is applicable to other wildland areas.
Salinity and Boron Tolerances of Candidate Plants for the Removal of Selenium from Soils
Authors: Parker D.R. , Page A.L. , Thomason D.N 
Published: July 2010

AbstractAgricultural drainage water from the west side of the San Joaquin Valley, CA is highly salinized, and is often contaminated with an assortment of metals and metalloids, including Se. Among proposed disposal options, vegetation management may be a critical component of remediation strategies designed to reduce soil or sediment concentrations of Se to safe levels. Soil salinity (mostly sodium sulfate) and B pose serious limitations to the use of many plant species. We screened a number of cultivars or lines of species from the genera Astragalus, Leucaena, Medicago, Trifolium, Elymus, Elytrigia, Festuca, Leymus, Oryzopsis, Psathyrostachys, Puccinellia, and Sporobolus for tolerance to salinity and B using solution culture methods. Considerable variation in tolerance to salinity, both within and across species, was observed during seed germination. Electrical conductivities required to produce a 50% reduction in germination (EC50) ranged from 5 to 30 dS m−1. Boron levels up to 4.0 mM had only minimal effects on germination. The most promising genotypes, representing some 15 species, were then tested for salinity and B tolerance during the seedling growth stage. Lines of five species (Astragalus bisulcatus, A. racemosus, Elytrigia pontica, Puccinellia dlstans, and Sporobolus airoides) appeared most promising; all exhibited EC50 values > 20 dS m−1 and were unaffected by B concentrations up to 4.0 mM during seedling growth. Astragalus bisulcatus and A. racemosus are considered primary accumulators of Se; their tolerance of high salinity and B daring seedling growth make them particularly good candidates for remediation of Se‐enriched soils and sediments.
Microlysimeter Soil Columns for Evaluating Pesticide Movement through the Root Zone
Authors: Fermanich K. J. , Daniel T. C. , Lowery B. 
Published: July 2010

AbstractField approaches to studying pesticide movement are subject to numerous variables of the environment, many of which are difficult and expensive to monitor. This study describes the design, construction, operation, and performance of intact microlysimeter soil (Plainfield loamy sand—mixed, mesic, Typic Udipsamment) columns used to examine the mobility of two insecticides through soil from two tillage plots (conventional‐moldboard plow and no‐till tillage). Field leaching conditions were approximated by simulating a moisture and temperature regime characteristic of a natural soil profile. Measured daily and seasonal temperature fluctuated according to a pattern characteristic of a field soil. Evapotranspiration (ET) from the soil columns was 61% of the total water applied and was nearly equal to the ET measured (63%) from field lysimeters of this soil planted to corn (Zea mays L.). Variation in cumulative drainage was small; total drainage from all columns was within a range of 3.9 cm. There was no significant difference in the transport of bromide (conservative tracer) through columns from the two tillage plots. Bromide leachate loss was 62 and 63% of the amount applied for conventional‐moldboard plow and no‐till columns, respectively. Intact soil columns established in a microlysimeter fashion provided a means to compare the movement of agricultural chemicals under controlled conditions in the greenhouse that approximate conditions/processes in the field.
Laboratory Measurements of Diffusion Coefficients for Trichloroethylene and Orthoxylene in Undisturbed Tuff
Authors: Fuentes H. R. , Polzer W. L. , Smith J. L. 
Published: July 2010

AbstractExploratory laboratory research was performed to evaluate the fate of two organic contaminants in the unsaturated zone of the Bandelier Tuff at Los Alamos National Laboratory chemical waste site. Studies concentrated on vapor phase diffusion for trichloroethylene and orthoxylene known to occur in significant amounts at the site. This research was undertaken in support of the geohydrological characterization of the unsaturated zone and ultimately to facilitate environmental transport predictions. In these vapor phase diffusivity studies a laboratory method was developed for direct measurement of gaseous diffusion through undisturbed cores of Bandelier Tuff. Core preparation required careful handling to maintain the in situ structure of the tuff samples, which were mostly cohesionless. Effective diffusion coefficients were calculated from a one‐dimensional steady‐state solution of Fick's first law. Effective diffusion coefficients for the target organics were determined for samples from two locations within each of two lithologic units of the Bandelier Tuff at two average extreme moisture contents, 1 to 3% and 12 to 15% (by mass). The higher moisture content decreased the flux of the organics by approximately one order of magnitude. Differences among effective diffusion coefficients between sampling locations and lithologic units were not significant for each organic at a 5% significant level. Results provide an insight on the effect of moisture content, but data are needed to further develop or validate a relationship between diffusion and moisture content.
Railway Right‐of‐Way Contaminants in the Lower Mainland of British Columbia: Polycyclic Aromatic Hydrocarbons
Authors: Wan Michael T. 
Published: July 2010

AbstractBallast from five railway rights‐of‐way and the adjacent ditches flowing to salmon streams in the Lower Mainland of British Columbia, Canada, were sampled in 1989 to determine the occurrence and levels of 16 selected polycyclic aromatic hydrocarbons (PAH). Reference and background levels of PAH in ditches leading to fish streams were obtained from pristine parklands and agricultural lands. PAH levels in sediments reported by Goyette and Boyd (1989) for Burrard Inlet (Inner Harbour), the commercial harbour of Vancouver, British Columbia, were used for comparison. All 16 PAH were found in the ballasts and ditch sediments/water of the five railway rights‐of‐way. In the ballasts, total levels of the 16 PAH varied from 1.562‐58.773 g/m2, averaging 18.069 g/m2. The mean concentration of the total 16 PAH in ditch sediments was 213.47 µg/g (range, 1.89‐1168.71 µg/g). PAH were not consistently found in ditch water at all study sites, but at sites where they occurred, the selected 16 compounds had an average total concentration of 606.9 ug/L (range, 1‐3515.9 µg/L). PAH were not detected in the ditches of pristine parklands but low concentrations were detected in some agricultural samples. The total level of the 16 PAH in sediments from railway ditches were respectively 205 and 40 times higher than levels found in the sediments of farmland ditches and Burrard Inlet. Some biological implications of PAH‐contaminated sediments and water from railway ditches discharging into fish habitats are discussed.
The Measurement of Bioavailable Phosphorus in Agricultural Runoff
Authors: Sharpley Andrew N. , Troeger W. W. , Smith S. J. 
Published: July 2010

AbstractThe role of sediment‐bound or particulate P in agricultural runoff in accelerating the biological productivity of surface water can be assessed if the biological availability of particulate P (PP) is known. Previous research has indicated amounts of P extracted from deposited river and lake sediments by 0.1 M NaOH to be correlated with P uptake by the alga Selenastrum capricornutum. This study investigates a modification of this extraction to allow routine quantification of potentially bioavailable particulate P (BPP) content of agricultural runoff from the Reddish Prairies and Rolling Red Plains land resource areas. In the proposed method, 20 mL of unfiltered runoff is shaken with 180 mL of 0.11 M NaOH for 17 h and BPP concentration calculated by subtraction of the soluble P (SP) concentration of the runoff sample. Total bioavailable P concentration (TBP) of runoff can be represented by BPP plus SP concentration. Growth of P‐starved S. capricornutum, incubated for up to 29 d with runoff sediment from nine watersheds, as the sole P source, was correlated (r2 = 0.76 to 0.95) with potentially BPP content of the added sediment. Sample dilution had no effect on the amount of P extracted from runoff sediment by NaOH across a range in sediment concentration of the extraction medium, equivalent to that observed for 95% of the runoff events. If the sediment concentration of runoff exceeds 20 g L−1, a smaller runoff sample is used in the extraction. The results indicate the applicability of the proposed extraction method to quantify the bioavailability of P transported in agricultural runoff.
Water Quality Impacts Associated with Sorghum Culture in the Southern Plains
Authors: Sharpley Andrew N. , Smith S. J. , Williams J. R. , Jones O. R. , Coleman G. A. 
Published: July 2010

AbstractNonpoint‐source pollution of surface water by the transport of sediment, N, and P in agricultural runoff is one of the nation's major water quality concerns. Consequently, concentrations and amounts of sediment, N, and P in runoff from Conventional Till (CT), Reduced Till (RT), and No Till (NT), sorghum [Sorghum bicolor (L.) Moench.] watersheds in the Southern Plains, were measured during a 5‐yr period to evaluate water quality impacts of sorghum culture. Mean annual sediment and total N and P loss in runoff from NT (281, 0.76, and 0.28 kg ha−1 yr−1, respectively) and RT (523, 0.99, and 0.37 kg ha−1 yr−1, respectively) were lower than from CT sorghum (8877, 7.28, and 2.5 kg ha−1 yr−1, respectively). In contrast, tillage effects on soluble N and P losses were generally small and less consistent, although soluble P concentrations exceeded limits associated with accelerated eutrophication (0.01 mg L−1). Predicted losses of soluble P and particulate N and P using desorption kinetics and enrichment ratio relationships were not significantly different from measured values for all tillage practices (r2 ranged from 0.66 to 0.99). Overall, conservation tillage (NT and RT) reduced sediment, N, and P transport in runoff relative to CT and thereby lessened the potential impact of sorghum culture on surface water quality in the Southern Plains.
Hydraulic Conductivity and Nitrogen Removal in an Artificial Wetland System
Authors: McIntyre Beverly D. , Riha Susan J. 
Published: July 2010

AbstractA greenhouse study using aquatic macrophytes rooted in sand was conducted to test if the presence of belowground plant material increases or maintains permeability in horizontal subsurface flow systems constructed for wastewater treatment. Nutrient solutions low in suspended solids (SS) and biochemical oxygen demand (BOD) were substituted for actual wastewater. Three batch applications of NH4‐N and three of NO3‐N were added for 48‐h periods at concentrations of approximately 20, 55, and 80 mg L−1 to assess the ability of these systems to remove N. Saturated hydraulic conductivity, Ks, was monitored over 236 d in boxes of sand planted with two different aquatic macrophytes—Typha glauca Godr. and Scirpus acutus Muhl. The Ks decreased over time in the vegetated and nonvegetated (control) systems. The decrease was significantly greater in the vegetated systems (55%) than in the control (41%). Despite these decreases, Ks at the end of the study was still high (0.62 cm s−1) even in the vegetated systems. The vegetated systems were significantly more effective than the nonvegetated at removal of NH4‐N and NO3‐N. No significant difference was noted in the N removal efficiency of the two plant species. Our results suggest that artificial wetlands using sand can be used to remove N from wastewater, but decreased soil permeability may occur.
Nitrification Potential in Reclaimed Coal Mine Spoils and Soils in the Semiarid Southwest
Authors: Sorensen D. L. , Fresquez P. R. 
Published: July 2010

AbstractThe functioning of the N cycle within mining wastes is necessary for revegetation and long‐term stability of the disturbed ecosystem. In view of this, an undisturbed area and eight reclaimed topsoil‐covered and without‐topsoil spoil areas at the San Juan coal mine in northwestern New Mexico (Fruitland formation, Upper Cretaceous period) were analyzed for initial N contents and nitrification rates to determine the potential of these disturbed but reclaimed areas to cycle N. The age of the reclaimed area varied from 0.2 to 8 yr. Total N, NH+4‐N, and NO−3 NO−2‐N concentrations were significantly higher (P ≤ 0.05) in without‐topsoil spoil areas than in the undisturbed soil or in any of the topsoil‐covered areas. Initial, potential nitrification activity was highest in a 5‐yr‐old reclaimed spoil area that also had the highest extractable NH+4‐N. Ammonium and nitrite oxidation activities were measurable in all of the reclaimed areas and in the undisturbed control. Rates of initial NH+4 and NO−2 oxidation were not well correlated but were similar in magnitude. Mixing as much as 0.75 kg kg−1 spoil material with soil delayed, but did not inhibit, nitrification.
Preferential Solute Transport through Macropores in Large Undisturbed Saturated Soil Columns
Authors: Singh Piyush , Kanwar Rameshwar S. 
Published: July 2010

AbstractSix large undisturbed soil columns (61 cm in length, 15 cm in diameter) were collected from three no‐till and three conventional tillage field plots. The side walls of these columns were sealed with either plaster of paris or paraffin wax to eliminate wall effects. After these columns were saturated with CaSO4 (0.005 M), CaCl2 (0.005 M) was applied at the surface and the effluent was collected at the bottom. Effluent samples were later analyzed for Cl (chloride) concentrations. The Cl breakthrough‐curves (relative Cl concentration vs. relative pore volume) were developed and the degree of preferential flow analyzed. Shape and other breakthrough‐curve parameters, such as immobile pore‐water fraction and initial breakthrough, indicated the occurrence of preferential flow through all columns. The degree of preferential flow, however, was greater in no‐till than in conventional tillage columns (average immobile pore‐water fraction was 56% for no‐till and 49% for conventional tillage columns).