bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Response of Radish to Nitrogen Dioxide, Sulfur Dioxide, and Ozone, Alone and in Combination
Authors: Reinert R. A. , Gray T. N. 
Published: July 2010

AbstractEffects on radish (Raphanus sativus L.) cv. ‘Cherry Belle’ of nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3) alone and in combination at 0.2 or 0.4 ppm of each pollutant were studied. There was no difference in foliage or root weight of radish between exposure durations of 3 or 6 hours, and no significant interaction of hours with air pollutant and concentration. Ozone reduced root dry weight more at 0.4 ppm than at 0.2 ppm. Sulfur dioxide depressed the root/shoot ratio at both 0.2 and 0.4 ppm; however, when NO2 and SO2 were both present there was synergistic depression of the root/shoot ratio at 0.4 ppm. The average O3‐induced reduction in root weight of radish (1.75 g fresh and 101 mg dry, per plant) was additive in the presence of NO2 and SO2. The weight of the root was reduced even though the foliage was the direct receptor of the pollutant stress.
Effect of pH and Redox Potential on Concentration of Dissolved Nutrients in an Estuarine Sediment
Authors: De Laune R. D. , Reddy C. N. , Patrick W. H. 
Published: July 2010

AbstractA study was conducted on sediment suspensions maintained under conditions of controlled pH (5.0, 6.5, and 8.0) and redox potentials (−200, 0, 250, and 500 mV) to determine the effect of these parameters on concentrations of dissolved organic C, P, NH4+, Fe, and Mn in an estuarine sediment. Concentration of these nutrients was strongly influenced by changes in sediment pH and redox potential. Dissolved organic C increased from 42 µg ml−1 at pH 5.0 and 500 mV, to 93 µg ml−1 at pH 8.0 and −200 mV. Soluble P, NH4+, Fe, and Mn concentrations increased with decreasing sediment redox potential and pH. Phosphorus concentrations ranged from 0.002 µg ml−1 at pH 8.0 and 500 mV, to 0.215 µg ml−1 at pH 5.0 and −200 mV. Iron and manganese concentrations ranged from <0.1 µg ml−1 at pH 8.0 and 500 mV, to 101 and 13 µg ml−1, respectively, at pH 5.0 and −200 mV.
Utilization Efficiency of Nitrogen from Sewage Effluent and Fertilizer Applied to Corn Plants Growing in a Clay Soil
Authors: Feigin A. , Feigenbaum Sala , Limoni Hedva 
Published: July 2010

AbstractEffects of irrigation with secondary municipal sewage effluents on N availability in a fertilized soil were studied in a greenhouse experiment using 15N as a tracer. Corn (Zea mays) was grown in a clay soil with ammonium‐N added as solid fertilizer, sewage effluent, and a mineral solution.Between 55 and 69% of the ammonium sulfate‐15N was taken up by the corn plants. Between 21 and 32% of the fertilizer‐N was recovered as organic‐N in the soil after 43 days, while negligible amounts of exchangeable‐NH4 and NO3 were detected. Losses of ammonium sulfate‐N applied to the soil before seeding, probably through denitrification, ranged between 6 and 15%. Similar results were obtained whether the fertilized soil was irrigated with demineralized water, sewage effluent, or a mineral solution simulating the mineral composition of the sewage effluent.About 61% of the tagged ammonium‐N applied as sewage effluent was taken up by the corn plants, and 14% was immobilized in the organic fraction of soil. About 24% of the effluent‐tagged‐ammonium‐N was lost, apparently through both denitrification and volatilization. The corresponding loss from the mineral‐solution‐tagged‐N was about 17%. The simultaneous application of C and N by sewage effluents was probably responsible for the increased losses of N through denitrification found in the effluent‐tagged‐ammonium‐N treatment.Recovery of N, in plant and soil, from ammonium sulfate incorporated into the soil before planting was somewhat greater than that of sewage effluent ammonium‐N, and was not affected by irrigation with sewage effluent.
Effects of Nitrapyrin on Nitrate Movement in Soil Columns
Authors: Owens L. B. 
Published: July 2010

AbstractThe purpose of the study was to consider the possible benefits of a nitrification inhibitor to control nitrate leaching in soils. Sandy loam soil cores were taken in 1‐m‐long polyvinyl chloride cylinders. After prewetting the cores, nitrapyrin (a nitrification inhibitor)‐treated urea was incorporated into the top 10 cm of three cores, and untreated urea was incorporated into the top 10 cm of three cores. The columns were leached periodically with distilled water. After 91 days, 1 and 9.7% of the applied N had leached from the nitrapyrin‐treated and untreated cores, respectively; after 144 days, 41.9 and 53.0%, respectively, of applied N had been leached. Short‐term studies indicated that further work using a nitrification inhibitor to reduce nonpoint source nitrate additions to ground water is justified.
Influence of PCBs in Water on Uptake and Elimination of DDT and DDE by Lake Trout
Authors: Hesselberg Robert J. , Nicholson Lawrence W. 
Published: July 2010

AbstractResearchers predicted that several hundred years would be required before DDT (1,1,1 trichloro‐2,2‐bis [P‐chlorophyl] ethane) and its metabolites were likely to decrease to nondetectable levels in Lake Michigan. But following the ban on DDT in 1970, residues of total DDT in Lake Michigan lake trout (Salvelinus namaycush) declined rapidly from 10.5 µg/g in 1970 to 5.7 µg/g in 1976. During this period, polychlorinated biphenyls (PCBs) were being detected in lake trout tissues at about 20 µg/g. It was hypothesized that the high level of PCBs being accumulated by fish may have influenced uptake and elimination of DDT and DDE (1,1‐dichloro‐2,2‐bis [p‐chlorophenyl] ethylene) by fish. To test this hyphophesis, fingeriing lake trout were exposed to various combinations of DDT, DDE (100 ng/liter), and PCBs (100 and 500 ng/liter) in water for 12 weeks. After DDT and DDe exposures were completed, exposure to PCBs was continued for an additional 16 weeks to measure any effect PCBs may have on the elimination of DDT and DDE by fish. Accumulation and elimination rates of DDT and DDE were compared. It was found that PCBs did not influence the accumulation or elimination rates of DDT or DDE in lake trout and therefore should not have had a major influence on the decline of DDT in lake trout.
The Hubbard Brook Ecosystem Study: Biogeochemistry of Lead in the Northern Hardwood Forest
Authors: Smith William H. , Siccama Thomas G. 
Published: July 2010

AbstractThe average annual Pb input to the northern hardwood forest at the Hubbard Brook Experimental Forest in central New Hampshire was 266 g ha−1 year−1 based on 4 years of records. Lead output via streamwater and eroded particulate matter was 5.0 and 1.1 g ha−1 year−1, respectively. Lead concentration in precipitation averaged 22 µg liter−1 and showed a significant decline over the 4 sample years (1975–1978).Lead input to the ecosystem via meteorological vectors is accumulated in the forest floor. Total current Pb content of the forest floor was 8.6 kg ha−1 and showed no significant differences along the elevation gradient of the watershed (400–800 m). Lead concentration in the forest floor was maximum on the ridge due to a minimum forest floor mass relative to the rest of the watershed. Within the forest floor, maximum Pb concentration is in the fermented (F) layer.Total Pb content of the forest biomass (stems ≥ 10 cm dbh) was 1,248 g ha−1. Lead concentration in the biota was in the following order: lichens (213 µg g−1) > mosses (190 µg g−1) > tree twigs (26 µg g−1) > roots (20 µg g−1) > bark (19 µg g−1) > leaves (7 µg g−1) = bracket fungi (7 µg g−1) > wood (0.7 µg g−1).Disturbance of the forest ecosystem through harvest cutting, other than through increased runoff, increased erosion, and transport of particulate matter, does not alter the biogeochemistry of Pb and does not result in increased mobility and export of Pb due to gross or subtle alterations of the behavior of Pb in the ecosystem.
Effects of Dairy Manure on Phosphorus Concentrations and Losses in Tile Effluent
Authors: Hergert G. W. , Klausner S. D. , Bouldin D. R. , Zwerman P. J. 
Published: July 2010

AbstractDissolved phosphorus concentrations and losses in effluent from a tile‐drained silt loam were compared before and after manuring. Effluent samples were collected from 0.33‐ha tile‐drained plots for 4 years before and 3 years during consecutive annual dairy manure applications of 35 or 200 wet metric tons/ha. Plots had received fertilizer P in years prior to manuring. More than 95% of the effluent samples had dissolved molybdate reactive P (DMRP) concentrations < 30 ppb before manuring. During the 3 years the manure was applied, 53 and 92% of the effluent samples contained < 30 ppb P for the 200‐ and 35‐metric‐ton applications, respectively. The flow‐weighted DMRP concentrations in tile effluent were 116, 441, and 97 ppb for 200 metric tons of manure/ha per year, and 22, 10, and 9 ppb for 35 tons/ha per year, respectively, during the 3 years manure was applied.The tile flow accounted for about 40% of the drainage water lost from the plots, but the P contents of tile flow were 10% of total dissolved P losses in surface runoff. P additions from 30 to 40 wet metric tons/ha of manure would be adequate to meet crop needs but should not produce excessively high P concentrations in tile flow.
Nitrogen Balances for an Effluent Irrigation Area
Authors: Lund L. J. , Page A. L. , Nelson C. O. , Elliott R. A. 
Published: July 2010

AbstractAn 8.5‐ha pasture irrigated with secondary sewage effluent was studied to determine the fate of N applied in the effluent. Soils of the Corralitos series (Typic Xeropsamment) at nine plots were sampled twice to evaluate the spatial and temporal variations in the field water contents and NO3‐N and Cl concentrations in the unsaturated zone below the root zone. Field water contents varied in space but not in time. Mean NO3‐N concentrations in the soil solution ranged from 15.4 to 32.4 mg liter−1 and varied significantly in space and time. Mean Cl concentrations varied in a similar manner. Averages of N balances developed for three of the nine plots attributed 32, 60, and 9% of the N applied in the effluent to crop removal, leaching, and gaseous losses, respectively.
Sand‐Filter Trenches for Purification of Septic Tank Effluent: II. The Fate of Nitrogen
Authors: Kristiansen Rolv 
Published: July 2010

AbstractIn some areas septic systems are suspected to cause an increased content of ground‐water N. For that reason, turnover of N in sandfilter trenches for septic tank effluent was investigated from July 1976 until November 1977 in three pilot‐plant sand filters operated at 12–15°C (unit A) and ambient temperature (units B and C), and at loading rates of 4–6 cm/day (A and C) and 12–18 cm/day (B). Results from chemical analysis of N in sand and water were compared to redox and other soil properties.Insignificant amounts of N were found to be removed from the effluent passing through the filters. Nitrification in the cold season was significantly affected by the sand temperature in equally loaded units. Nitrification occurred between 7.5 and 27 cm below the crust in unit A, which also had the highest clogging intensity. In the other units nitrate was predominately found near the bottom air vent. This was due to low clogging intensities leading to low contents of air‐filled pore spaces.Nitrogen bound in the microbial biomass, adsorbed to the cation exchange complex, and bound in dead organic material could amount to about three months of loading of N from a single‐family home to a standard 20‐m sand filter. Because of aerobic conditions and lack of suitable energy sources in zones containing nitrate, insignificant denitrification occurred in the sand‐filter trenches.Intermittent loading or recycling of nitrified effluent are suggested as methods of improving denitrification in septic systems.
Enzyme Activities in Revegetated Surface Soil Overlying Spent Paraho Process Oil Shale
Authors: Sorensen D. L. , Klein D. A. , Ruzzo W. J. , Hersman L. E. 
Published: July 2010

AbstractTechniques for covering Paraho retorted oil shale with surface soil to allow more efficient revegetation have been evaluated for 2 years in the Piceance Basin of Colorado. In this study, several key microbiological parameters related to soil development and biogeochemical cycling processes have been monitored to evaluate possible relationships between surface soil management and soil microbiological responses.Surface soil of 30‐, 61‐, and 91‐cm depths placed directly over Paraho processed oil shale showed appreciable reduction in nitrogenase (acetylene reduction), dehydrogenase, and phosphatase activities as compared with surface soil not in contact with processed shale. The decreased nitrogenase and dehydrogenase activities in these soils placed directly over the processed shale at the various depths were not significantly different (P ≤ 0.05). With a 30‐cm coarse rock capillary barrier between 61 cm of soil and the processed shale, the soil had nitrogenase and phosphatase activities which were not significantly lower (P ≤ 0.05) than the control soil. Interactive effects of seeding mixtures and fertilization on nitrogen fixation potential were also suggested, with introduced species plot soils not showing decreased nitrogen fixation potentials that were observed with the native species plots. These field results suggest that a capillary barrier may allow better maintenance of microbial processes in soils placed over Paraho retorted shale during revegetation.
The Release of Soil Phosphorus to Runoff in Relation to the Kinetics of Desorption
Authors: Sharpley A. N. , Ahuja L. R. , Menzel R. G. 
Published: July 2010

AbstractThe release of P from surface soil to runoff water under simulated rainfall conditions was investigated for five soils at several rates of fertilizer P application. A simplified kinetic model proposed earlier, describing the desorption of soil P, adequately described both the concentration of soluble P in runoff during an event and mean values for successive events. During an event the logarithm of soluble P concentration decreased linearly as the logarithm of time increased. Mean soluble P concentrations of individual runoff events increased linearly with amount of desorbable P in the surface soil (top 0.5 cm), while the effect of increased rain intensity on concentrations could be explained by a power function related to water/soil ratio. The average depth of runoff‐surface soil interaction calculated from the data using the kinetic model ranged from 1.5 to 3.0 mm for the five soils, and was significantly related to degree of soil aggregation. These depths agreed closely with those determined using 32P as a tracer in earlier studies. The depth of interaction increased with increase in soil slope, kinetic energy of the raindrops, and, to a lesser extent, rainfall intensity. The use of the kinetic model would improve modeling of soluble P loading in runoff.
Greenhouse Evaluation of Solum and Substratum Materials in the Southern Illinois Coal Field: I. Forage Crops
Authors: Dancer W. S. , Jansen I. J. 
Published: July 2010

AbstractMore than 75% of the surface‐mined coal in Illinois is produced in southern counties, where soils have a very strongly acid and nutrient‐deficient subsoil that limits root penetration and water availability.Slightly acid (pH 6.2) C1‐material and mildly alkaline glacial till (pH 7.5) overburden strata are readily available in these coal fields, and could be used in post‐mining soil construction. Our objective is to identify overburden materials that can be used as an alternative to the very strongly acid (pH 4.7) subsoil. This study compared the growth of three forage test crops on representative Weir silt loam topsoil (Ap) and subsoil (B2), with deeper C1‐material (B3 and C1 strata), and Illinoian glacial till (IIIC stratum). All of the overburden materials studied significantly responded to lime and fertilizer with topsoil supporting the best plant growth without amendment.The very strongly acid subsoil was shown to be inferior to the leached C1‐material found immediately below it. Amendment with high levels of lime and fertilizer was required to achieve maximum productivity on the native subsoil. Blending the subsoil with the C1‐material was shown to be a viable alternative to liming it, and provided a more desirable texture as well.
Reclamation of Quartz Sand‐Tailings from Phosphate Mining: I. Tropical Forage Grasses
Authors: Mislevy P. , Blue W. G. 
Published: July 2010

AbstractPhosphate mining in Florida produces waste products of phosphatic colloidal material and quartz sand. Quartz sand‐tailings disposal areas cover 20–60 ha and support no vegetation. A split‐plot field experiment was conducted to study the production, quality, and nutrient concentration of five tropical grasses: (i) ‘McCaleb’ stargrass (Cynodon aethiopicus Clayton et Harlan), (ii) ‘Transvala’ digitgrass (Digitaria decumbens Stent.), (iii) ‘Pensacola’ bahiagrass (Paspalum notatum Flugge), (iv) ‘Ona’ stargrass (Cynodon niemfuensis Vanderyst var. niemfuensis), and (v) ‘Callie’ bermudagrass (Cynodon dactylon var. aridus Harlan et deWet), grown on four amended sand‐tailing treatments. These treatments were: (i) sand‐tailing control (SC), (ii) colloidal phosphate (CP) at 336 metric tons/ha, (iii) CP at 336 metric tons/ha + oven‐dry sewage sludge (SS) at 45 metric tons/ha, and (iv) CP at 336 metric tons/ha + top soil (TS) at 1,460 metric tons/ha.Generally all grasses produced highest dry matter yields when grown on CP + SS and CP + TS amended sand‐tailing treatments during the first 2 years of the experiment; however, during the 3rd year no difference (P <0.05) was obtained among amendment treatments. Highest forage production during all 3 years was obtained from Callie bermudagrass (average of 14.4 metric tons/ha). Amendment treatments had no effect on forage quality (in vitro organic matter digestion [IVOMD] and crude protein) of perennial grasses, with Transvala digitgrass usually averaging the highest percentage IVOMD and crude protein. Transvala digitgrass also contained the highest nutrient concentrations (P, 0.39%; K, 1.55%; Ca, 0.62% and Mg, 0.26%).
Reclamation of Quartz Sand‐Tailings from Phosphate Mining: II. Forage Legumes
Authors: Mislevy P. , Blue W. G. , Brolmann J. B. 
Published: July 2010

AbstractQuartz sand‐tailings are a waste product from the phosphate mining industry in southwest Florida. A split‐plot field experiment was conducted to study the performance of the tropical forage legumes: (i) ‘Siratro’ (Macroptilium atropurpureum (DC.) Urb.), (ii) ‘Florida’ Carpon desmodium (Desmodium heterocarpon (L.) DC), (iii) ‘Caribbean’ stylo 7303 (Stylosanthes hamata (L.) Taub.), (iv) ‘Stylo mix’ (31 cultivars) (Stylosanthes spp.), and (v) ‘Florida 66’ alfalfa (Medicago sativa L.), a temperate legume, on four amended sand‐tailing treatments. These treatments were: (i) sand‐tailings control (SC), (ii) colloidal phosphate (CP) at 336 metric tons/ha incorporated, (iii) CP at 336 metric tons/ha + oven‐dry sewage sludge (SS) at 45 metric tons/ha incorporated, and (iv) CP at 336 metric tons/ha + top soil (TS) at 1,460 metric tons/ha incorporated.Siratro, stylo mix, and alfalfa all demonstrated rapid emergence and development on sand‐tailings, especially when seeded on the SC and CP treatments. These three species also produced the highest (P < 0.05) yields during the initial harvest season.The first winter after establishment, a freeze at the experimental site killed all entries except alfalfa and Siratro. Throughout the remainder of the study alfalfa outyielded siratro by 250% on all treatments except CP + TS treatments, where alfalfa plants died in 1977.Forage quality measurements (in vitro organic matter digestion and crude protein) of alfalfa were higher (P < 0.05) than those for Siratro, with little difference in forage quality between sand‐tailing treatments. The P, K, Ca, Mg, Mn, Cu, and Zn concentrations in the forage of both legume species were more than adequate for good animal performance. The double‐acid‐extractable P (4,520 kg/ha) and Ca (8,540 kg/ha) were extremely high on all treatments.
Effects of Simulated Acid Rain on Glucose Mineralization and Some Physicochemical Properties of Forest Soils
Authors: Strayer Richard F. , Alexander Martin 
Published: July 2010

AbstractTo study the effects of acid rain, samples of forest soils were exposed to a continuous application of 100 cm of simulated acid rain (pH 3.2–4.1) at 5 cm/hour, or to intermittent 1‐hour applications of 5 cm of simulated acid rain three times per week for 7 weeks. The major effects of the simulated acid rain were localized at the top of the soil and included lower pH values and glucose mineralization rates, and higher exchangeable Al and total and exchange acidity. The acidity penetrated further in the more acid soils. The mineralization of 14C‐glucose was measured at concentrations of 1.5–54 µg glucose/g of soil. Glucose mineralization in the test soils (pH values of 4.4–7.1) was inhibited by the continuous exposure to simulated acid rain at pH 3.2 but not at pH 4.1. The extent of inhibition depended on the soil and the initial glucose concentration. Exposure of one soil to 7 weeks of intermittent applications of simulated acid rain at pH 3.2 reduced the mineralization rate at the three glucose concentrations tested. These data suggest that acid rain may have a significant impact on microbial activity.
Sediment Yield from a Mississippi Delta Cotton Field
Authors: Dendy F. E. 
Published: July 2010

AbstractSediment yield from flat (0.2% slope) delta fields was measured during a 33‐month study. Annual erosion rates were higher than anticipated, ranging from a maximum 12 metric tons ha−1 for a year of above normal rainfall to a minimum 5 metric tons ha−1 for a year of slightly below normal rainfall. Highest sediment concentrations in runoff occurred in the spring during the seedbed preparation and planting season when the soil was bare of vegetative cover, freshly plowed, and highly susceptible to erosion. Lowest concentrations occurred in September and October when vegetative cover was good.Sediment particle size data from selected storms showed that about 83% of the sediment removed from the fields was < 2 µm in diameter and nearly all, 98% was < 16 µm. Field soils were composed of 24% clay, 23% silt, and 53% sand, so considerable enrichment of fine particles occurred during the erosion process. This indicates that most sediment deposits in streams and lakes of the area are composed of fine materials and that gradual enrichment of coarse particles in the soils is occurring over long periods of time.
Comparative Uptake of Actinides by Plants and Rats from the Shoreline of a Radioactive Pond
Authors: Garten Charles T. 
Published: July 2010

AbstractTo compare the bioaccumulation of several actinide elements by plants and rats from a contaminated pond shoreline, concentrations of 233U, 238U, 241Am, 244Cm, and 239Pu were measured radiochemically in shoreline sediment, emergent macrophytes, cotton rats (Sigmodon hispidus), and soil and fescue grass (Festuca sp.) collected 3–5 m away from the shoreline, of a former low‐level liquid radioactive waste pond. The relative extractability of actinides from the shoreline sediment using 1M HNO3 and 0.01M HCl was U > Am = Cm > Pu. Actinide concentrations in shoreline plants, expressed as geometric means, were 2–150 times greater than in fescue collected away from the pond shoreline. Concentrations of actinides in rat gastrointestinal tracts were greater than or equal to concentrations in shoreline plants. From a comparison of plant/sediment and rat‐carcass/sediment or rat‐carcass/plant concentration ratios, the conclusion is that the relative uptake of actinides by plants and rats from the pond shoreline was Pu < Am ≤ Cm < 233U = 238U.