bluuebunny/crossref_metadata_2025_split huggingface dataset:
Topographic Influences on Soil Water and Spring Wheat Yields on Reclaimed Mineland
Authors: Schroeder S. A. 
Published: July 2010

AbstractTopographic positions on undisturbed soils affect available soil water and crop yields. Reclaimed minelands are required by regulation to have productivity levels “equal to or greater than” premine levels. Since a normal reclamation technique is to place uniform depths of topsoil and subsoil across the topography, this technique often changes the topsoil and subsoil depths from the premine condition. The objective of this research was to determine if these changes in topsoil and subsoil depths have resulted in effects on soil water and crop yields unlike those documented for undisturbed soils. This study was initiated on reclaimed mineland in 1986 at two North Dakota coal mines where topographic positions (summit, shoulder, backslope, and footslope) were monitored for 6 yr for available water at planting, spring wheat (Triticum aestivum L.) yields, and soil water recharge from harvesting to planting the following year. Results showed that downslope topographic positions had nearly 300% more available soil water at planting (0‐ to 1.2‐m depth due to greater recharge) and generally significantly greater (P = 0.10) spring wheat yields than upslope positions. Relationships between total water use and wheat yields were similar to those found for undisturbed soils. These results seem to suggest that the uniform depths of replaced topsoil and subsoil have not affected soil water and wheat yields differently on reclaimed minelands than on undisturbed landscapes in a semi‐arid climate.
Soil Ventilation: Effects on Microbial Populations in Gasoline‐Contaminated Subsurface Soils
Authors: Hickey W. J. 
Published: July 2010

AbstractShort‐ and long‐term effects of vapor extraction (VE) in an unsaturated subsurface soil and in situ biodegradation of gasoline were evaluated in a field study. Subsurface temperature, moisture, solid‐ and gas‐phase contaminant levels, atmospheric gases, nutrient levels, and microbial population densities were measured during and after soil VE for 462 d. Microbial activity, based on in situ O2 consumption rates, measured 7 d after VE started averaged 3.8% O2 d−1; by Day 62 these rates dropped to 0.2% O2 d−1. Soil VE was stopped on Day 180 and about 70 d elapsed before renewed, low‐level (0.05% O2 d−1) activity was detectable. Following a second round of VE, average O2 consumption rates increased to 0.11% O2 d−1. Microbial population densities did not consistently reflect activity changes measured by O2 consumption. Activity increases in the latter part of the study were not adequately accounted for by changes in subsurface moisture levels, temperature, or contaminant vapor concentrations. At the study's completion, 400 kg of gasoline was volatilized from the soil and another 139 kg estimated to be biodegraded in situ. A two‐phase process is proposed to account for the effects of VE on microbial activity. The initial phase is characterized by declining microbial activity levels in response to substrate reduction. Microbial activity slowly increases as a result of interactions between gasoline vapor concentrations and possibly changes in degradative activities of the microbial population. More work is needed to identify the gasoline constituents serving as substrates for microbial populations before and after ventilation.
Minesoil Properties of 15 Abandoned Mine Land Sites in West Virginia
Authors: Johnson C. D. , Skousen J. G. 
Published: July 2010

AbstractThe characteristics of minesoils on abandoned mine land (AML) often dictate which plant species will invade and establish from nearby undisturbed areas. This study measured physical and chemical minesoil properties on 15 AML sites in northern West Virginia and matched these properties to vegetation cover. Fifteen sites ranging in age from 13 to 35 yr old were selected from three surface‐mined coal beds (Pittsburgh, Freeport, and Kittanning). On each site, three 1 m‐deep pits were dug and minesoil samples were extracted from two horizons, and vegetation was sampled in three 100‐m2 plots near the pits. Minesoils on Freeport sites had more rock fragments and sand than either Pittsburgh or Kittanning sites. No particle‐size changes with depth or age were evident between horizons in any minesoil. Acidity increased and pH decreased with minesoil age on Pittsburgh and Kittanning minesoils due to the oxidation of pyritic materials near the soil surface. A cluster analysis distinguished three minesoil types on these sites. Minesoil type A had low acidity and high CEC. Minesoil type B had high acidity and moderate CEC. Minesoil type C had high rock fragment content, low to moderate acidity, and low CEC. Minesoil type A was completely covered by herbaceous plants and trees, while minesoil types B and C were generally covered by trees. Based on our minesoil analyses and other studies, barren AML sites may not require complete redisturbance for revegetation but may be revegetated by adjacent plant species if surface amendments are applied.
Test of the LEACHP Model for Predicting Atrazine Movement in Three Minnesota Soils
Authors: Khakural B. R. , Robert P. C. , Koskinen W. C. , Sorenson B. A. , Buhler D. D. , Wyse D. L. 
Published: July 2010

AbstractLeaching Estimation and Chemistry Model‐pesticide (LEACHP) was evaluated for predicting atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) movement in sandy loam (sandy, Typic Hapludoll), silt loam (fine‐silty, Typic Hapludoll), and clay loam (fine‐loamy, Typic Haplaquoll) soils under moldboard and chisel plow tillage practices. Atrazine distribution in the root zone was measured by analyzing soil cores. Model predictions were compared with observed atrazine concentrations in the soil profiles on various dates after application (two to three growing seasons). Model performance was evaluated by testing whether model predictions fall within a specified factor of true values and using Goodness‐of‐Fit tests (maximum error, root mean squared error, coefficient of determination, modelling efficiency, coefficient of residual mass). LEACHP predicted depth of peak atrazine concentration in the soil profile accurately in all three soils (under both moldboard [MB] and chisel plow [CP] treatments and at all sampling dates). It predicted depth of atrazine movement and atrazine concentrations in the soil profile reasonably well in the Estherville soil (sandy, mixed, mesic Typic Hapludoll) except some disparities between measured and predicted concentrations in 1988 because of the difficulty in recovering representative samples. In Port Byron (fine‐silty, mixed, mesic Typic Hapludoll) and Webster soils (fine‐loamy, mixed, mesic Typic Haplaquoll), depth of atrazine movement and atrazine concentrations in the soil profile were predicted reasonably well during relatively dryer years (1988 and 1989). In a relatively wet year (1987), however, the model did not predict significant amounts of atrazine at depths >45 cm, whereas, 2.5 to 27.5 µg kg−1 of atrazine were detected in soil samples during earlier sampling dates (43, 73 DAA in Port Byron and 14, 43 DAA in Webster soils). Overall performance of the model was similar in both tillage treatments (MP or CP). Considering the broad range in soil properties and climatic conditions used in testing, the model performed well.
Effects of Ozone and Water Deficit on Field‐Grown Soybean: I. Leaf Gas Exchange
Authors: Vozzo Steven F. , Miller Joseph E. , Pursley Walter A. , Heagle Allen S. 
Published: July 2010

AbstractOzone (O3) and water deficit can suppress net carbon exchange rate (NCER) of plant tissues, but little is known concerning their combined effects on NCER of field‐grown plants. Soybean [Glycine max (L.) Merr. ‘Young’] plants were exposed to two soil moisture regimes (providing well‐watered and periodically water‐deficient conditions) and three levels of O3 in open‐top field chambers throughout the growing season. Seasonal (12 h d−1) mean O3 concentrations were 0.018, 0.059, or 0.085 µL L−1. Measurements of NCER, transpiration (Tn), and stomatal resistance (Rs) were conducted periodically on center leaflet of the fifth or sixth trifoliolate from the apex. During vegetative and early reproductive growth, less visible foliar injury due to O3 occurred on water‐deficient plants. Ozone usually suppressed leaflet NCER and leaflet WUE (NCER/Tn). Leaflet NCER was usually suppressed and WUE increased in water‐deficient treatments during water deficit episodes. Diurnal measurements illustrated that leaflet NCER was limited in water‐deficient plants when leaf water potential fell to about −1.1 MPa. On two occasions under low photosynthetically active radiation, NCER was greater for leaflets in water‐deficient treatments than in well‐watered treatments. Significant O3 × H2O interactions for NCER were infrequent on individual days, although water deficit suppressed response to O3 when data were analyzed over the season.
Leaching of Nitrate, Atrazine, and Metribuzin from Sugarcane in Southern Louisiana
Authors: Southwick L. M. , Willis G. H. , Johnson D. C. , Selim H. M. 
Published: July 2010

AbstractWe have studied the leaching losses of NO3, atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine], and metribuzin [4‐amino‐6‐(1,1‐dimethylethyl)‐3‐(methylthio)‐1,2,4‐triazine‐5(4H)‐one] applied to sugarcane (Saccharum officinarum L.) planted in Mississippi River alluvial soil in southern Louisiana. Nitrogen (122 kg/ha) and atrazine (2.24 kg/ha) were applied in June, and atrazine (2.24 kg/ha) and metribuzin (1.12 kg/ha) were applied in December; losses through a Sharkey clay (very fine, montmorillonitic, nonacid, thermic Vertic Haplaquepts) into subsurface drains (5.5‐ and 10.9‐m spacing) were measured for about 100 d in both seasons. Five days after application NO3‐N appeared in its highest concentrations (5–11 mg/L) in the drain water; after this first event, concentrations remained below 10 mg/L throughout the summer season. After application in the summer atrazine appeared in the subsurface drains at its highest seasonal concentrations (114–144 µg/L) on the day of application; after 4 to 7 wk these concentrations remained below 3.0 µg/L. Total losses in the summer amounted to 3 to 8% of the NO3 application and 0.6 to 1.2% of the atrazine application. Almost 50% of the NO3 leaching into the subsurface drains occurred after Day 76, whereas 82% of the atrazine leached into the drains by Day 8. After the winter application, high concentrations of atrazine (67–81 µg/L) and metribuzin (52–94 µg/L) were measured within 8 d. Similarly, large concentrations of atrazine occurred in the drain water throughout the winter season. The much higher concentrations of atrazine during the winter study, compared with the summer, coincided with soil surface concentrations that were 3 to 10 times those of the summer. Total losses during the winter were 0.4 to 2.0% (atrazine) and 0.4 to 1.7% (metribuzin) of the applications. Evidence for preferential flow into the drains of the NO3 and the herbicides is presented.
Effects of Diet on Ungulate Excretion of Enterococcus spp., Streptococcus bovis, and Streptococcus equinus in Feces
Authors: Darby Neal W. , Mosley Jeffrey C. , Davitt Bruce B. , Bohach Gregory A. 
Published: July 2010

AbstractWe compared fecal streptococci (FS) quantities and species composition excreted by native and domestic ungulates that were consuming various feed rations. Group 1 was comprised of elk (Cervus elaphus), white‐tailed deer (Odocoileus virginianus), and bighorn sheep (Ovis canadensis) fed alfalfa (Medicago sativa) hay. Group 2 consisted of elk, cattle (Bos spp.), mule deer (Odocoileus hemionus), domestic sheep (Ovis aries), and horses (Equus caballus) grazing separate grass paddocks of similar botanical composition. Group 3 had four subgroups of cattle each fed a different feed ration: (1) grain and silage; (2) hay, grain, and silage; (3) hay; and pasture. The FS were isolated from ungulate species in each group using the membrane filter technique. Filters were placed on KF streptococcus agar and all pink to red colonies were counted. The FS composition was determined by randomly selecting 20 colonies from each filter and then identified by using growth characteristics and C source utilization. Forage samples were analyzed for crude protein (CP) and neutral detergent fiber (NDF). Ungulates did exhibit some differences in FS quantities and composition, however, all FS species were present in most all ungulates and occurrences were highly variable. Nutritive quality of ungulate diets on grazed forage did not greatly affect the quantities and composition of FS excreted, but trends were difficult to discern because of the high variability of FS samples. Botanical composition of ungulate diets altered both FS quantities and composition. The FS quantities from cattle were greatest when cattle were fed grain rations and smallest when cattle consumed hay or pasture forage. Streptococcus bovis proliferated in feces of cattle fed grain and silage rations while S. equinus and Enterococcus durans dominated on pasture and hay diets. We concluded that the use of FS as indicators of fecal pollution from specific ungulates is unreliable in most cases because of the effects of forage nutritive quality and botanical composition.
Chlorimuron Adsorption, Desorption, and Degradation in Soils from Conventional Tillage and No‐Tillage Systems
Authors: Reddy Krishna N. , Zablotowicz Robert M. , Locke Martin A. 
Published: July 2010

AbstractNo‐tillage (NT) and other conservation management practices designed to enhance plant residue accumulation can affect the herbicides fate in soil. This study was designed to evaluate adsorption, desorption, and degradation of chlorimuron {ethyl 2‐[[[[(4‐chloro‐6‐methoxy‐2‐pyrimidinyl)amino]carbonyl]amino] sulfonyl]benzoic acid} in soils collected from long‐term conventional tillage (CT) and NT plots. Soils were Miami silt loam (fine‐silty, mixed, mesic, Typic Hapludalf) and Drummer silty clay loam (fine‐silty, mixed, mesic, Typic Endoaquoll) from Illinois, and Dundee silt loam (fine‐silty, mixed, thermic Aeric Ochraqualf) from Mississippi. Adsorption was determined on five concentrations of 14C‐chlorimuron (0.22–12.26 µmol kg−1) equilibrated for 72 h. Desorption in four cycles (1, 24, 24, and 24 h) was measured for samples initially sorbed at 2.60 µmol kg−1. Adsorption Kf values ranged from 0.56 to 6.53 and were higher in NT compared with CT soils. The N values were less than unity in all soils. Desorption was hysteretic and the total amount desorbed in four desorptions ranged from 18 to 51% of that sorbed. Desorption Kf values ranged from 0.60 to 2.74 and were higher in NT compared with CT soils. After 63 d incubation of 14C‐chlorimuron, 44 to 54% of applied remained as extractable chlorimuron and 10 to 16% of applied mineralized to 14CO2 among the soils. Half‐life of over 2 mo and relatively low mineralization suggests poor adaptability of native microbial populations to chiorimuron as substrate. Differences in the chlorimuron degradation pattern were minor between NT and CT soils, despite NT soils in general having greater organic C, microbial populations, and soil enzyme activity compared with CT soils.
Shoot and Root Development of Tall and Hard Fescues in Two Different Soils
Authors: Brar G. S. , Palazzo A. J. 
Published: July 2010

AbstractTall (Festuca arundinacea Schreb.) and hard fescue [Festuca ovina var. longifolia (L.) Koch] are among the most widely sown grasses used to stabilize disturbed soils in both the cool‐humid and transition climatic zones of the USA. Our objective was to evaluate the root and shoot development of two turfgrasses grown in sand and silt loam soils. Significant differences in leaf area, plant height, shoot and root dry matter, root depth (RD), root branching (RB), and root length (RL) were recorded with tall fescue compared with hard fescue. Greater leaf area, leaf number, plant height, shoot and root dry matter, and RL were observed when the grasses were grown in a silt loam soil. Greater RD and root/shoot ratio were recorded in sandy soil. Both turfgrass species and soil texture affected leaf area, leaf number, plant height, shoot dry matter, RD, RL, RB, root dry matter, and the root/shoot ratio. Significant correlations were obtained for shoot dry matter with root dry matter and RL; leaf area with shoot dry matter and root dry matter; root dry matter with TRL and RB; RD with root/shoot ratio; RL with leaf area; and RB with TRL and RD. Turfgrasses and soil types had an significant impact on shoot and root development. A greater understanding of early root development for these grasses will assist in developing techniques for establishment and persistence under disturbed soils and adverse climatic conditions.
Biodegradation of Phenol, 2,4‐DCP, 2,4‐D, and 2,4,5‐T in Field‐Collected Rhizosphere and Nonrhizosphere Soils
Authors: Boyle Jay J. , Shann Jodi R. 
Published: July 2010

AbstractThis study investigated xenobiotic biodegradation in rhizosphere soil collected from field‐grown plants, grouped for analysis as monocots or dicots. Microbial activity was highest in monocot rhizosphere soils, followed by dicot rhizosphere soils and, finally, nonrhizosphere soils. No differences were seen between these soils in the mineralization of phenol or 2,4‐dichloropbenol (2,4‐DCP), but there were differences in 2,4‐dichlorophenoxyacetic acid (2,4‐D) and 2,4,5‐trichlorophenoxyacetic acid (2,4,5‐T) mineralization. The rate constants for 2,4‐D or 2,4,5‐T mineralization in nonrhizosphere soil were lower than those for either rhizosphere soil. Monocot rhizosphere soil mineralized these compounds faster than dicot rhizosphere soil. Thus, soils that had a prior association with a plant showed significantly increased rates of mineralization for the more recalcitrant compounds tested. In addition, this enhanced mineralization in the rhizosphere appeared to be dependent on the type of plant involved.
Analysis of Cobalt(II)EDTA and Cobalt(III)EDTA in Pore Water by Ion Chromatography
Authors: Taylor D. L. , Jardine P. M. 
Published: July 2010

AbstractMonitoring and restoration activities at contaminated waste facilities throughout the USA have identified complicated mixtures of organic and inorganic contaminants in soil and groundwater. Inorganic contaminants are sometimes associated with various chelating agents (termed co‐contaminants), which alter the geochemical behavior of the contaminants in subsurface environments. Until recently, the significance of the chelating agents was usually dismissed, and they were not routinely measured as part of environmental compliance programs. A method is presented for separating and quantifying the common subsurface co‐contaminant species of CoEDTA in aqueous solution. Cobalt(II)EDTA and Co(III)EDTA are separated by an ion chromatograph using a carbonate, bicarbonate eluant, and quantified in the presence of common pore‐water inorganic anions using electrical conductivity and visible light detectors. The chromatograph detects Co(II)‐EDTA to 0.6 µmol L−1 with a linear range >4000 µmol L−1. Cobalt‐(III)EDTA is detected to 1.8 µmol L−1 with a linear range >860 µmol L−1. The method has application in basic scientific research and environmental restoration activities.
Soil Erosion Contribution to Pesticide Transport by Furrow Irrigation
Authors: Agassi M. , Letey J. , Farmer W. J. , Clark P. 
Published: July 2010

AbstractMovement of pesticides from fields in runoff water and on sediment can degrade surface waters. Research typically found that because of the high water‐to‐sediment ratio, the total amount of pesticide in water greatly exceeded that associated with sediment. These observations suggested that erosion control would have little effect in reducing pesticide transport from the field. A laboratory study was conducted in a miniature furrow system to determine whether reduction in erosion would contribute to a reduction of napropamide [2‐α‐naphthoxy)‐N,N‐diethylpropionamide] transport. Variable erosion was created by polymer addition to the water combined with using variable water flow rates. Bromide was used as a nonsorbing independent tracer. Napropamide transport was linearly related to the amount of fine soil particulates eroded. Bromide transport was independent of the amount of erosion, and the percentage of the applied Br− removed in the runoff was less than that of napropamide. The results indicate that reduction in erosion of fine particulates will result in reduced transport of sorbed pesticides from the field.
Dissolved Organic Carbon In Northern Hardwood Stands With Differing Acidic Inputs and Temperature Regimes
Authors: Liechty Hal O. , Kuuseoks Eimar , Mroz Glenn D. 
Published: July 2010

AbstractWe monitored concentrations and fluxes of dissolved organic carbon (DOC) in throughfall and forest floor solutions in two northern hardwood stands located at the northern and southern end of a latitudinal acidic deposition and air temperature gradient in the Great Lakes Region to determine if DOC levels are altered by regional and temporal variation in acidic inputs and temperature. Amounts of precipitation received at the two sites were similar, but precipitation pH and air temperature, respectively, averaged 4.83 and 13.9°C at the northern gradient site and 4.29 and 15.1°C at the southern gradient site. Volume weighted DOC concentrations in throughfall were significantly greater at the northern (20.5 mg L−1) than the southern (15.9 mg L−1) site, but these differences in DOC levels were caused by the differing amounts of throughfall passing through the canopy of the two sites rather than levels of precipitation acidity or air temperature. Temporal variation in the levels of DOC in throughfall was not related to the variation in either precipitation acidity or air temperature. Like throughfall, levels of DOC in forest floor solutions were not found to be altered by acidic inputs. However, DOC in these solutions increased with seasonal increases in soil temperature. A regression equation relating seasonal variation in soil temperature and forest floor concentrations of DOC estimated that an observed 2.1°C difference in soil temperature at the two sites during the growing season could represent as much as 3.7 mg L−1 difference in forest floor solution concentrations of DOC.
Simulating Saline Water Management Strategies with Application to Arid‐Region Agroforestry
Authors: Letey J. , Knapp Keith C. 
Published: July 2010

AbstractIrrigation projects have greatly increased agricultural productivity in arid and semiarid regions, but they frequently contribute as well to saline high water tables, which must be mitigated by a drainage system. Drainage waters, sometimes contaminated by toxic elements, can lead to environmental degradation if not properly managed. One option is to irrigate salt‐tolerant plants with drainage water to further increase the salt concentration while reducing the volume that would ultimately require treatment or disposal. Transient and steady‐state models were used to simulate the consequences of applying saline drainage water to eucalyptus trees (Eucalyptus camaldulensis) under conditions typical to the San Joaquin Valley of California. Simulated results agreed well with limited field data. High evapotranspiration and large tree growth require application of large amounts of water, leading to large, deep percolation volumes. Degradation of soil physical properties by saline water could reduce the transmission of water through soil. This limits the quantities of irrigation water that can be applied, with consequent poor tree growth and low evapotranspiration.