bluuebunny/crossref_metadata_2025 huggingface dataset:
Sediment Characteristics of Eleocharis acicularis (L.) R. and S. Sites in Streams and Lakes of Central Pennsylvania
Authors: Kroh Glenn C. , Schein Richard D.
Published: July 2010

Many streams of central Pennsylvania are polluted by sulphuric acid from coal mining operations. The most prevalent organism in these streams is an aquatic macrophyte—Eleocharis acicularis (L.) R. and S. (slender spikerush). An experiment using 32P determined that slender spikerush can absorb nutrients into its roots and transport them to the leaves. Chemical analyses of sediment from 14 spikerush sites indicates that these sedges are “generalists” with regard to the chemical parameters, but have a requirement for a predominantly silt‐clay sediment. As an acid tolerant aquatic macrophyte that can inhabit sediment covering a great range of chemical parameters, slender spikerush is ideally suited both functionally (as a primary producer) and structurally (stabilize alluvial sediment and provide physically heterogeneous niches for periphyton and heterotrophic invertebrates), for projects designed to reclaim mine‐acid polluted streams of central Pennsylvania.
Battery‐Operated Air Sampler for Remote Areas
Authors: Brown K. W. , Wiersma G. B. , Frank C. W.
Published: July 2010

An air sampling system developed to evaluate air quality in biosphere reserves or in other remote areas is described. The equipment consists of a Dupont P‐4000A pump and a specially designed battery pack containing Gates batteries.

This air sampling system was tested in southern Utah and at 10 remote sampling sites in the Great Smoky Mountains National Park. The equipment was backpacked to the remote sampling sites, and was operated continuously at full capacity for a maximum 8‐day period. Except for tampering by curious hikers at one site, the equipment operated satisfactorily.
Modeling Sewage Sludge Decomposition in Soil: I. Organic Carbon Transformation
Authors: Hsieh Y. P. , Douglas Lowell A. , Motto Harry L.
Published: July 2010

Mineralization of an activated and a digested sewage sludge in soil was studied in laboratory incubations. The activated sludge had a much higher mineralization rate than the digested sludge, mainly due to a larger portion of active organic carbon and less stability of the organic matter. After around 2 months of incubation, the mineralization rates of both sludges approached a square foot function of time. The amount of active organic carbon is a characteristic of sewage sludge and is important in determining the aerobic‐anaerobic status of the system. The mineralization of sewage sludges was proportional to the rate of sludge application at least up to 8% in the digested sludge and up to 4% in the activated sludge systems at 22°C. Between 8 and 22°C, the mineralization rate of sludges in soil increased about 1.9 times for every 10°C increase in temperature. Moisture levels between 0.06 and 0.33 bars had no significant effect on mineralization of the sludges. A regression model was developed in the form of an exponential function among the cumulative organic carbon mineralized and factors of time, sludge rate, and temperature. The model requires a minimal number of parameters to define the system and was least biased in regression analysis over a wide range of conditions.
Interaction Between High Levels of Applied Heavy Metals and Indigenous Soil Manganese
Authors: Korcak R. F. , Fanning D. S.
Published: July 2010

The importance of indigenous soil Mn level on plant Mn uptake from metal salt or sewage sludge amended soils was investigated. Twelve soil materials, six surface and six subsurface, were amended with either varying rates of a composite of Cd, Cu, Ni, and Zn sulfate salts, equivalent to the total of these metals present in a digested sewage sludge (Washington, D.C.) at rates of 0–896 dry metric tons/ha or with the sludge itself, at 224 dry metric tons/ha. Corn (Zea mays L.) was grown in the greenhouse for 30 days, 1 year after amendment application. Two pH levels of about 5.5 and 6.5 were maintained during the experiment on the metal salt amended soil materials.

Plant tissue Mn levels increased with the application of Cd, Cu, Ni, and Zn (in combination) as metal salts or as sewage sludge over the range of soil materials used. The amount of increase with a given increase in applied metals was greater for the unlimed than for the limed metal salt treatments. Elevated tissue Mn concentrations were positively and significantly correlated with the indigenous levels of soil Mn. A tissue Mn level of over 3,000 µg/g was observed with unlimed metal salts equivalent to 896 dry metric tons/ha of sludge with Manor Ap horizon soil material. Studies by others suggest that elevation of tissue Mn levels may be related to replacement of Mn from Mn “oxides” by the applied heavy metals.

The interaction between applied heavy metals and indigenous soil Mn may affect guidelines for disposition of metal‐bearing wastes on soils. Soils regarded as acceptable for waste disposition, but which have high native Mn levels, may produce higher plant tissue Mn levels than similar soils with lower native Mn.
Nitrogen Contents of Streams Draining an Agricultural and a Forested Watershed in Central Italy
Authors: Caporali F. , Nannipieri P. , Pedrazzini F.
Published: July 2010

Water samples from an agricultural and a forested watershed (33,180, and 4,090 ha, respectively) were analyzed during the 1979 water year to determine the concentration of NO3‐N, NH4‐N, NO2‐N, and organic‐N. Monthly fluctuations in the concentration of NO3‐N from the agricultural watershed may represent an interaction of organic matter mineralization and N fertilization at the time of seeding. From both watersheds NO3‐N and NH4‐N concentrations do not exceed the upper limits recommended for drinking water.

From both watersheds practically all monthly N losses, calculated as the product of the average flow and the respective average N concentration, occur during late autumn and winter and are more dependent upon total flow than upon concentration and land use. From the forested watershed yearly organic‐N and NO3‐N losses account for the same proportion of total N losses. From the agricultural watershed yearly NO3‐N losses, owing to higher concentrations, are nearly double the organic‐N losses.
Effect of Anhydrous Ammonia Fertilization on Emission of Nitrous Oxide from Soils
Authors: Bremner J. M. , Breitenbeck G. A. , Blackmer A. M.
Published: July 2010

A simple method was developed for accurate injection of anhydrous ammonia in field studies to assess the effects of this fertilizer on emissions of nitrous oxide (N2O) from soils. Use of this method and of a chamber technique for measurement of N2O emissions showed that fertilization of three Iowa soils with anhydrous ammonia (250 kg N/ha) led to a very marked increase in emission of N2O. Emissions of N2O‐N from the fertilized soils in 139 days ranged from 12.1 to 19.6 kg/ha and averaged 15.6 kg/ha. The corresponding emissions from the unfertilized soils ranged from 1.7 to 2.5 kg/ha and averaged 2.0 kg/ha. Most of the N2O evolved from the fertilized soils was produced within 42 days after fertilization, and N2O emissions from these soils 96 days after fertilization were not appreciably greater than those from the corresponding unfertilized soils. The fertilizer‐induced emissions of N2O‐N observed after application of anhydrous ammonia greatly exceeded those detected in similar field studies using other N fertilizers and represented 4.0–6.8% of the fertilizer N applied.
Uranium Conversion and Enrichment Technologies: Sources of Atmospheric Fluoride
Authors: Taylor Fred G. , Hetrick David M. , Conrad M. Clark , Parr Patricia D. , Bledsoe Jean L.
Published: July 2010

To illustrate the proportional hydrogen fluoride (HF) residuals from two nuclear fuel cycle technologies, uranium hexafluoride (UF6) conversion (feed) and enrichment, air, and vegetation monitoring data were obtained from the Paducah (Kentucky) Gaseous Diffusion Plant (PGDP) from 1972 to 1977, during which the feed manufacturing plant and the diffusion cascade were operating. In the spring of 1977 the feed plant was placed on standby such that effluents containing fluoride came only from the gaseous diffusion operation. Monitoring data obtained without emissions from feed manufacturing (1978) were also obtained. Gaseous fluoride was collected in alkaline solution (NaOH) scrubbers until 1974, when they were replaced by chemically treated (K2CO3) filter papers. Air samples were collected weekly (7‐day averaging time) from 10 stations around the facility. Results indicate the absence of routine releases with observed fluoride concentrations randomly distributed. Of the total number of observations during the 6‐year period, 90% of the concentrations were < 1 µg/m3 (7‐day average). Ambient concentrations consisted of infrequent peaks superimposed upon a predominant distribution of lower concentrations. The scatter plot, by station, reflects distributions downwind and upwind from the source and identifies the area of greatest impact. Vegetation monitoring data were obtained for the same period (1972–1978), collected every 2 months from 18 locations. The vegetation data were summarized by scatter plots which reflect air quality data, depict ranges in concentration among the monitoring network, and identify the stations with significant fluoride accumulation.

Ground‐level air (HF) concentrations in the environs of the PGDP were estimated using two dispersion models (Atmospheric Transport Model and Climatological Dispersion Model) and compared to the observed data. The Atmospheric Transport Model estimates were less than the observed concentrations, because the model estimates considered only a single source (gaseous diffusion), whereas the monitoring data incorporated emissions from feed manufacturing and gaseous diffusion operations.
Hydrocarbons of Aquatic and Terrestrial Origin in Mountain Streams of the Marmot Basin
Authors: Telang S. A. , Hodgson G. W. , Baker B. L.
Published: July 2010

The abundance of n‐alkanes in stream waters of the Marmot Creek drainage basin was studied to develop an understanding of the source of hydrocarbons in a pristine mountain stream. The n‐alkanes varied in concentration from 0.02 µg/liter to 0.06 µg/liter and exhibited a bimodal distribution with one grouping in the range of C15–C23 and the other between C25–C32. Carbon preference indices (1.2 and 4.0, respectively) suggested that the first group was largely produced by nonphotosynthetic aquatic organisms and second was from soil and terrestrial vegetation. The contributions from stream and soil were roughly equal. Hydrocarbons in pristine mountain streams thus appeared to be derived both from autochthonous and allochthonous sources. Isoprenoid hydrocarbons were present in lesser abundance than alkane hydrocarbons. Abundance of the isoprenoids relative to n‐alkanes indicated that little, if any, degradation of n‐alkanes occurs in the stream waters. Aromatic hydrocarbons were not present above detection limits of 1 ng/liter.
Salt Release and Movement in Processed Oil Shale
Authors: Fransway D. F. , Wagenet R. J.
Published: July 2010

Salts present as a component of processed, discarded oil shale represent not only a potential environmental hazard, but also a detrimental influence in the reestablishment of vegetation on processed shale disposal sites. The saline characteristics of Paraho processed oil shale were investigated in a two‐phase series of laboratory experiments. The first phase studied the release of salts from two naturally distributed shale particle sizes packed in lysimeters constructed of plastic pipe and subjected to five leaching situations. All the lysimeters were instrumented with a porous‐cup‐vacuum system that allowed periodic nondestructive sampling of the soil solution with depth and time. Electrical conductivity and specific ion concentrations were measured. The second phase of the experiments involved subjecting three particle sizes of shale to a variety of shale/water ratios. The subsequent solutions were analyzed for electrical conductivity (EC) and concentrations of Ca, Mg, Na, K, Cl, and SO4.

The lysimeter experiments demonstrated the highly soluble nature of the salts present in the Paraho processed shale. These salts are primarily composed of Mg, Na, and SO4 and are predominately in the precipitated form, existing external to the shale. The most efficient treatments for removing salt from the upper 60 cm of the shale were those in which large (about 0.5 pore volumes) pulses of water were applied. To reduce the EC to acceptable levels (<4.0 mmho/cm) required application of approximately 2 pore volumes of water.

Results of the batch studies indicate a proportional relationship between dilution ratios and EC on a log‐log scale. Similar EC and dilution ratio relationships were observed for the cation sums. Ion analysis showed Mg and Na to be as much as 93% of the total water‐soluble cations and SO4 to be the dominant anion.
Toxaphene and Sediment Yields in Runoff from a Mississippi Delta Watershed
Authors: Mc Dowell L. L. , Willis G. H. , Murphree C. E. , Southwick L. M. , Smith S.
Published: July 2010

Toxaphene (chlorinated camphene) and sediment concentrations in runoff from a 15.6‐ha watershed, planted to continuous cotton (Gossypium hirsutum L.), were measured from 1973 through 1975 to determine the toxaphene and sediment yields and to define the major mode of toxaphene transport. The watershed, consisting of Sharkey silty clay soil (Vertic Haplaquepts), had been land‐formed to a mean slope of 0.2%. Measurements indicated a linear relationship between toxaphene yield and sediment yield in runoff. Sediment yields were 28.9, 26.3, and 13.4 metric tons/ha in 1973, 1974, and 1975, respectively, when annual rainfall was 37, 50, and 22 cm above the 30‐year average (125 cm). Although no toxaphene was applied in 1973, the residual toxaphene concentration in the soil from previous applications was 3.5 µg/g. Toxaphene yield in 1973 was 117 g/ha. Toxaphene yields in 1974 and 1975, when 10.1 and 11.2 kg/ha of toxaphene were applied, were 97 and 54 g/ha, respectively, amounting to only 1 and 0.5%, respectively, of the amounts applied. In 1975, 93% of the toxaphene yield was attached to the sediments and only 7% was transported in solution. Toxaphene and sediment yields were greatest during the spring tillage‐planting‐cultivating period, but toxaphene concentrations in runoff and sediment were greatest during the summer application period. Improved erosion control practices are needed in the Delta to reduce the loss of valuable topsoil and to reduce the water pollution potential from sediment and toxaphene.
Changes in Soil Physical Properties Due to Organic Waste Applications: A Review
Authors: Khaleel R. , Reddy K. R. , Overcash M. R.
Published: July 2010

Land application of organic wastes such as animal manure, municipal wastes, and sewage sludge could alter the soil physical properties. Repeated substantial applications of waste increase the soil organic matter percentage. The available data on effects of waste applications on soil physical properties such as bulk density, water holding capacity at both field capacity and wilting point, and saturated hydraulic conductivity were summarized. Based on data from 12 different sources, 21 soil types, 7 waste types, and 8 crop types, a linear regression analysis of observed increases in soil organic C as a result of waste applications on percent reduction in bulk density indicated a highly significant relationship (r2 = 0.69**). The results of an exponential multiple regression analysis of percentage sand and increase in organic C percentage on the percent increase in water holding capacity indicated that approximately 80% of the observed variations in percent increases in water holding capacity, at both field capacity and wilting point, could be attributed to variations in soil texture and soil organic C increases. The data on hydraulic conductivity as well as on infiltration rates are very limited and are not sufficient for quantitative analyses. The limitations of the available data were discussed in terms of identifying future research needs.
Disruption of Hardwood Nutrition by Sulfur Dioxide, Nickel, and Copper Air Pollution Near Sudbury, Canada
Authors: Lozano F. C. , Morrison I. K.
Published: July 2010

Foliage from each of four hardwood species—white birch (Betula papyrifera Marsh.), red oak (Quercus rubra L.), red maple (Acer rubrum L.), and trembling aspen (Populus tremuloides Michx.)—growing on sites severely and moderately damaged by fumes and dustfall and on control sites near Sudbury, Ontario, and soil from beneath the trees were sampled and analyzed for various chemical constituents. Results indicated that on sites damaged by fumes and dustfall, soils were impoverished with respect to organic matter content, exchangeable bases (particularly Ca and Mg), and trace elements (particularly Mn and Zn). Levels of S, Fe, Cu, and Ni were also increased. Foliage analysis provided additional support for the proposition that soils contained near toxic to toxic levels of Ni and Cu. If conditions improve, however, with respect to suppression of Ni or Cu supply, tree growth could be limited by the availability of Ca, Mg, or Mn, or even of N or P.
Comparative Uptake of Uranium, Thorium, and Plutonium by Biota Inhabiting a Contaminated Tennessee Floodplain
Authors: Garten Charles T. , Bondietti Ernest A. , Walker Raymond L.
Published: July 2010

The uptake of 238U, 232Th, and 239Pu from soil by rescue, grasshoppers, and small mammals was compared at the contaminated White Oak Creek floodplain in East Tennessee. Comparisons of actinide uptake were based on analyses of radionuclide ratios (U/Pu and Th/Pu) in soil and biota. U:Pu ratios in small mammal carcasses (shrews, mice, and rats) and bone samples from larger mammals (rabbit, woodchuck, opossum, and raccoon) were significantly greater (P ±0.05) than U/Pu ratios in soil (based on 8M HNO3 extractable). There was no significant difference between Th/Pu ratios in animals and soil. The order of actinide accumulation by biota from the site relative to contaminated soil was U > Th ≈ Pu.
The Sorption of Soluble Phosphorus by Soil Material during Transport in Runoff from Cropped and Grassed Watersheds
Authors: Sharpley A. N. , Menzel R. G. , Smith S. J. , Rhoades E. D. , Olness A. E.
Published: July 2010

The adsorption of soluble P by surface soil and suspended sediment material during transport in surface runoff under field and simulated laboratory conditions was investigated. The soluble P concentration of surface runoff from several Southern Plains cropped and grassed watersheds decreased with an increase in sediment concentration, A linear inverse relationship between soluble P and sediment concentration was significant over a wide range in sediment concentration. The slope values of the relationship were similar for different watersheds on the same major soil type. Using soil from these watersheds in simulated surface runoff, sorption of soluble P added in rainfall was found to occur during transport. The magnitude of this sorption was more closely related to the sorptive capacity of the sediment in the surface runoff than to that of the surface soil material. The results suggest that for unfertilized watersheds and for watersheds where fertilizer P is incorporated into the surface soil, away from the zone of immediate removal in surface runoff, the leaching of P from the vegetative cover can contribute significant amounts of soluble P to runoff, and that soil material may act as a P sink rather than a P source.
Effect of Cadmium on Symbiotic Soybean Plants
Authors: Borges A. Chaer , Wollum A. G.
Published: July 2010

The potential for environmental contamination by cadmium (Cd) has increased significantly in recent years. Since Cd may be hazardous to living systems, a study was conducted to investigate: (i) the existence of Rhizobium japonicum strains tolerant to Cd, (ii) the Cd effect on the symbiosis between host soybean plants (Glycine max (L.) Merr.) and R. japonicum strains with different Cd tolerances, and (iii) interactions and distribution of Cd and other elements in the host when biomass is decreased by Cd.

The existence of R. japonicum strains tolerant to Cd was assessed by comparing growth curves of 10 different strains growing in a basal medium with gluconate, yeast extract, L‐arabinose, and Cd (0, 3.5, 7, 14, and 28 µg/ml). Strain 3Ilb110 (110) exhibited a tolerance to Cd after an initial lag in growth, while strain 3Ilb123 (123) was susceptible.

Strains 110 and 123 were used to inoculate plants growing in nutrient solution with Perlite as a support medium to evaluate the plant‐rhizobial interactions in the presence of 0, 2.2, 6.7, 10.1, and 20.2 µg Cd/ml, respectively. Plants were harvested and tops, roots, and nodules were analyzed 23 days after starting Cd application.

Cadmium decreased dry matter production of tops, roots, and nodules. Plants inoculated with strain 123 accumulated significantly more dry matter in nodules than those with strain 110. However, in the presence of 0 and 2.2 µg Cd/ml, plants inoculated with strain 110 accumulated significantly more N than plants inoculated with strain 123.

Nutrient imbalances were observed in the presence of Cd. It is suggested that the interactions of Cd with some nutrients may contribute to Cd toxicity in soybean plants. In this study the most pronounced Cd effect was on Fe and Mn nutrition, rather than Zn as had been previously reported.
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

Effects 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

A 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

Effects 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

The 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

Researchers 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

The 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

Dissolved 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

An 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

In 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

Techniques 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

The 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

More 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

Phosphate 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

Quartz 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

To 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

Sediment 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

To 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.
Plant Uptake and Growth Responses from p‐Chlorophenyl Methyl Sulfide, ‐Sulfoxide, and ‐Sulfone in Soil
Authors: Guenzi W. D. , Beard W. E. , Bowman R. A. , Olsen S. R.
Published: July 2010

A greenhouse experiment was conducted to determine the effects of three soil chemical concentrations of 14C‐ring labeled p‐chlorophenyl methyl sulfide, ‐sulfoxide, and ‐sulfone on seedling growth and uptake by alfalfa (Medicago sativa L.), corn (Zea mays L.), tall fescue (Festuca arundinacea Schreb.), sugarbeet (Beta vulgaris L.), and spring wheat (Triticum aestivum L.). Each crop was tested in separate experiments during a 3‐month period in an Ascalon sandy loam (Aridic Argiustoll). Effects on growth were determined from plant height, dry matter production of roots and tops, and visual toxicity symptoms of leaves. Plant uptake of chemicals was evaluated from calculations using total 14C activity measurements of combusted plant samples. In most cases, there appeared to be little difference among the three chemicals. Reduction of root and top growth (dry weight) for each plant species was linearly related to increases in soil chemical concentrations. Growth reduction at a given chemical concentration varied among crop species, with alfalfa being the most susceptible and corn the least susceptible. The calculated mean soil concentrations of the three chemicals responsible for a 20% reduction in dry weight of tops were 4.7, 6.3, 7.3, and 15.5 ppm for alfalfa, rescue, sugarbeet, and wheat, respectively. The 20% reduction for corn was only obtained from the 2$‐ppm sulfone treatment.

Chemical concentration in plant tissue increased almost linearly with increasing soil concentrations. The linear correlation coefficients were r = 0.894** (tops) and r = 0.942** (roots).
Effects of Sewage Sludges and Composts on Soil Porosity and Aggregation
Authors: Pagliai M. , Guidi G. , La Marca M. , Giachetti M. , Lucamante G.
Published: July 2010

Modifications induced in soil porosity and in stability of soil aggregates were studied for 2 years on an Italian sandy loam soil. Aerobic and anaerobic sludges and their composted mixtures with the organic fraction of urban refuse were used and compared with manure. Addition rates were equivalent to 50 and 150 metric tons/ha of manure on the organic carbon basis. A control plot was also present. Porosity and pore size distribution were measured on thin sections prepared from undisturbed soil samples by using electro‐optical image‐analysis equipment. The stability of soil aggregates was determined by a wet‐sieving method.

All organic materials increased the total porosity significantly at all sampling times. Differences between the two application rates were generally not significant. The improvement of total porosity caused by sludges and composts was comparable to that of manure. Modifications of pore size distribution were also observed. Stability of soil aggregates increased slightly in treated samples. The best stabilizing effect was shown by the anaerobic sludge.