bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental and Predicted Movement of Three Herbicides in a Water‐Saturated Soil
Authors: Davidson J. M. , McDougal J. R. 
Published: July 2010

AbstractThe equilibrium adsorption characteristics of 1,1‐dimethyl‐3‐(a,a,a‐trifluoro‐m‐tolyl) urea (fluometuron), 4‐amino‐3,5,6‐trichloropicolinic acid (picloram), and 2,4‐bis(isopropylamino)‐6‐(methylthio)‐s‐triazine (prometryne) on Ca‐saturated Norge loam soil were measured and were found to fit the Freundlich equation. A solution of each herbicide was displaced through a water‐saturated colume of Norge loam soil at various average pore‐water velocities (5.6 to 0.57 cm/hour) and effluent samples evaluated to determine the importance of adsorption kinetics to the mobility of the herbicide. The displacement of each herbicide through the soil was significantly influenced by the average pore‐water velocity. The use of a kinetic adsorption model in a convective transport equation did not adequately predict the shape of the effluent concentration distribution at the high pore‐water velocities, but did give the left‐hand shift exhibited by the data. The tailing noted in all the herbicide effluent concentration distributions resulted primarily from the nonsingularity between the adsorption‐desorption process. Equilibrium adsorption and desorption isotherms were measured for picloram on Ca‐saturated Norge loam soil.
Disposal of Composted Municipal Waste in a Plantation of Young Slash Pine: Effects on Soil and Trees
Authors: Bengtson G. W. , Cornette J. J. 
Published: July 2010

AbstractA field experiment was conducted to determine the effects of disposal of garbage compost on soil and trees in a 2‐year‐old plantation of slash pine (Pinus elliottii Engelm. var. elliottii) on an excessively drained sandy soil in central Florida. The highly carbonaceous compost was applied at three rates (0, 4.4, and 44 metric tons/ha) in factorial combination with inorganic N fertilizer (0 vs. 224 kg/ha) and with disking vs. no disking following compost application.At 44 metric tons/ha the compost increased the amount and extended the period of moisture availability to the trees during a drought occurring soon after treatment. Disking (with or without applied compost) also improved soil moisture availability temporarily by reducing weed competition. The compost, particularly at the high rate, decreased soil acidity, and modestly increased soil organic matter, cation exchange capacity, and exchangeable Ca, Mg, and K.Nitrogen concentration in pine foliage was reduced following application and incorporation of the high rate of compost, but recovery to pretreatment levels was rapid. Concentration of K in foliage was increased by compost application; this effect was persistent.Height growth of the trees was significantly increased only by disking; this effect diminished in the second year following treatment. No adverse effects of compost on soil or trees were observed, but aesthetics of the site were degraded somewhat by the residue of nondegradable particulates which persisted on the soil surface.
An Analytical Consideration of Undersoil Heating
Authors: Trezek George J. , Obeng Dennis 
Published: July 2010

AbstractThe feasibility of using reject heat from electrical power plants for undersoil heating has been analytically considered. Since soil is a poor thermal conductor, a suitable arrangement of undersoil pipes is required in order to achieve a somewhat uniformly elevated soil temperature. Two‐dimensional steady temperature profiles in soil resulting from a warm water pipe having a wall temperature of 37.8C were computed for several pipe configurations and surface heat transfer coefficients of 1.36 and 136 cal·sec−1·m−2·°C−1. Values of heat transfer on the order of 5 cal·sec−1·m−1 can be obtained. Calculations indicate that in order to apply this technique for the utilization of significant portions of reject heat, the system must be viewed in terms of an agricultural power plant complex encompassing large quantities of land.
Nitrate in Surface and Subsurface Flow from a Small Agricultural Watershed
Authors: Jackson W. A. , Asmussen L. E. , Hauser E. W. , White A. W. 
Published: July 2010

AbstractA small agricultural watershed on Cowarts loamy sand in the Georgia Coastal Plains was planted in corn (Zea mays L.) each year from 1969 to 1971. Surface and subsurface water samples were collected during each natural rainfall runoff event and NO3‐N was determined.The initial weighted average NO3‐N concentration was 5 ppm in the subsurface runoff for 3 months before the first planting. The average was 7 ppm in 1969, 10 ppm in 1970, and 9 ppm in 1971. The concentration of NO3‐N in most of the surface runoff for 3 years was less than 1 ppm; the maximum was 3 ppm. Subsurface flow accounted for 80% of the total runoff during the study period. Thus, greater amounts of NO3‐N were discharged in subsurface flow than in surface flow from this watershed.
Inositol Polyphosphates in Activated Sludge
Authors: Cosgrove D. J. 
Published: July 2010

AbstractAlthough it is known that some of the soluble inorganic phosphate present in waste water can be fixed as organic forms in the activated sludge process, there is little knowledge of the chemical nature of these products. Recently, the extraction of “inositol phosphate” from activated sludge was described, but whether the product consisted only of myo‐inositol phosphates or was a mixture was not determined. In the present investigation, inositol polyphosphates were extracted from activated sludge using methods previously developed in investigations of soil organic phosphates. Ion exchange chromatography of the purified extract showed it to be a mixture of penta‐ and hexaphosphates of myo‐, chiro‐, scyllo‐ and neo‐inositol and thus to resemble the inositol polyphosphate component of soil organic matter. As the same polyphosphate mixture does not apparently occur in raw sewage (hydrolysates of dried raw sewage were found to contain no other inositol but the myo‐isomer), it would appear that it is formed as a result of biological action during the aeration process.
Nitrogen Transformations and Availability of an Anaerobically Digested Sewage Sludge in Soil
Authors: Ryan J. A. , Keeney D. R. , Walsh L. M. 
Published: July 2010

AbstractSamples (50 g) of Warsaw sandy loam soil (Typic Argiudoll) were incubated under aerobic conditions with varying levels of an anaerobically digested sewage sludge (up to 1,880 ppm N on an oven‐dry soil basis). Total N, NH4‐N, (NO3+NO2)−N, NH3 volatilization, and hydrolyzable forms of N were determined periodically during 16 weeks of incubation at room temperature (23 ± 3C). At low levels (≤ 235 ppm N), the inorganic N was all converted to (NO3+NO2)‐N while at the higher levels (≥ 940 ppm N), a significant amount of NH4‐N was not nitrified even after 16 weeks of incubation. Recovery of added N was nearly quantitative at the low levels of sewage sludge addition. However, at the higher levels, there was evidence of concurrent nitrification‐denitrification. The hydrolyzable N distribution results indicated that very little of the hydrolyzable N was mineralized at the low rates of application. At the high rates of application, apparent development of anaerobic conditions led to more rapid mineralization of the sewage sludge organic N than was found under aerobic conditions. The data indicate that from 4 to 48% of the organic N in the sewage sludge was mineralized to (NO3+NO2)−N in 16 weeks. Thus, the availability of sewage sludge organic N must be considered when evaluating the potential of the material as a fertilizer or a possible source of NO3‐N to ground waters.
Fluoride Accumulation by Forage: Continuous vs. Intermittent Exposures to Hydrogen Fluoride
Authors: MacLean D. C. , Schneider R. E. 
Published: July 2010

AbstractThe pattern of fumigation with gaseous HF markedly affects the rate and amount of F accumulated by timothy (Phleum pratense L.) and red clover (Trifolium pratense L.) plants. F accumulation was greater after continuous fumigations than when the same HF dose was provided in alternate 48‐hour exposures. The importance of the intermittent nature of exposures in addition to the pollutant concentration and duration of exposure in governing F accumulation suggests that pollution abatement action to protect livestock from ingested F should be based on the F content of forage rather than the concentration of airborne fluorides.
Phosphorus Relationships in Runoff from Fertilized Soils
Authors: Römkens M. J. M. , Nelson D. W. 
Published: July 2010

AbstractThe effect of P fertilizer mixed into soil on the P composition of runoff was studied. Runoff samples from artificial rainstorms on fallow plots of Russell sil soil, and P enriched soil‐water mixtures (1:50) of Russell sil and selected other soils were analyzed for water soluble orthophosphate and extractable, total, and organic P in sediment. The relation of P addition rate to the soluble orthophosphate or sediment extractable phosphorus level in runoff was approximately linear. The relation of soluble orthophosphate to extractable P in soil‐water systems was linear for most soils studied. Soluble orthophosphate and extractable P in sediment were not related to total P or to organic P in sediment. A procedure was suggested for estimating the soluble orthophosphate concentration in runoff from fertilized wet soil using laboratory analyses.
Loss of Mercury(II) from Solution
Authors: Newton D. W. , Ellis Roscoe 
Published: July 2010

AbstractLoss of mercury(II) from dilute solutions was studied using 203Hg(II) as a tracer. Magnitude and rate of loss depend on Hg(II) concentration, chemical composition of carrier solutions, and container material. Losses were severe only at Hg(II) concentrations of 10−6M (0.2 ppm) or lower. Of the Hg‐containing solutions studied, loss was greatest from 0.01M CaCl2; Hg(II) was stable at all levels in concentrated HNO3. Increasing pH from 4 to 8 appeared to reduce Hg loss. Adding KMnO4 also reduced losses. Glass and plastic containers differ in their ability to retain Hg(II) in solution. The problem of Hg loss has serious implications in analyses of Hg as an environmental contaminant and in research where low concentrations of Hg are used.
Fate of Mirex‐14C During and After a 28‐Day Feeding Period to a Lactating Cow
Authors: Dorough H. Wyman , Ivie G. Wayne 
Published: July 2010

AbstractThe use of mirex [1,3,4‐methenododecachlorooctahydro‐2H‐cyclobuta (c,d) pentalene] for the control of the imported fire ant in pasture land is a potential source of contamination of meat and milk of dairy animals. To determine the level and nature of the residues which might occur should the animals consume the insecticide in the diet, mirex‐14C was administered via gelatin capsules twice daily to a lactating Jersey cow for 28 days. The daily dose was equivalent to approximately 0.2 ppm mirex in the diet. Radioactive residues in the feces reached a maximum of 50% of the consumed dose after 3 weeks and remained at that level until treatment was terminated. An additional 3% was eliminated in the feces during the 28‐day post‐treatment period. Mirex‐14C equivalents in the milk reached an equilibrium after about 1 week of treatment. Approximately 10% of the administered doses were eliminated daily by this route with the concentration in the whole milk after equilibration being 0.058 ppm. One week after removing the mirex source, the residues in the milk dropped to 0.006 ppm and then declined gradually to 0.002 ppm after 28 days. Residue levels in the tissues 28 days after the final treatment were: fat, 0.21 ppm; liver, 0.03 ppm; and kidney, 0.02 ppm; the muscle and brain contained no detectable residues. TLC (thin‐layer chromatography) and GLC (gas‐liquid chromatography) analyses of the milk, feces, and fat demonstrated that unchanged mirex‐14C was the only radioactive component of these substrates.
Effect of Beef‐Feedlot‐Lagoon Water on Soil Chemical Properties and Growth and Composition of Corn Forage
Authors: Wallingford G. W. , Murphy L. S. , Powers W. L. , Manges H. L. 
Published: July 2010

AbstractLand disposal of beef‐feedlot‐lagoon (runoff) water was studied. Rates of 0, 8, 15, 26, and 46 cm/year of lagoon water were applied during the summers of 1970 and 1971 by furrow irrigation to a silty clay loam soil. Corn (Zea mays L.) forage yield and plant content of N, P, K, Ca, Mg, and Na were measured. Surface soil samples and soil cores were taken from the plots after harvest each year.Electrical conductivity ranged from 1.6 to 7.6 (3.1 average) mmho/cm in the lagoon water applied at the study site and from 1.0 to 12.8 mmho/cm in samples taken from 12 Kansas feedlots. Electrical conductivities of extracts from saturated pastes of the surface soil samples were increased linearly by accumulative treatment both years. The 1970 and 1971 soil cores showed accumulations of NO3−‐N, P, K, and Na in the top 30 cm at all treatment rates. Movement of NO3−‐N and Na down to 100 cm was noted in the 1971 cores from plots receiving 46 cm/year. Ca and Mg in the soil cores were not affected by treatment either year. Corn forage yields were a linear function of treatment in 1970 and a quadratic function in 1971. The positive effect on yield both years was attributed to increased soil fertility; the relative decrease in 1971 at the 26 and 46 cm/year rates was attributed to increased soil salinity. Maximum yield and uptake of N and P were reached at the 15 cm/year disposal rate in 1971.
Transformations of Methylamines and Formation of a Hazardous Product, Dimethylnitrosamine, in Samples of Treated Sewage and Lake Water
Authors: Ayanaba A. , Alexander M. 
Published: July 2010

AbstractAdded trimethylamine is converted to dimethylamine in samples of raw sewage and lake water, and the secondary amine thus formed or added dimethylamine disappears with time. The rates of formation and disappearance of dimethylamine are governed by the pH and the type and amount of inorganic N present. Ammonium is generated from both of the amines. Dimethylnitrosamine, a potent carcinogen, is formed in small amounts in samples of sewage and lake water receiving dimethylamine and nitrite, the maximum nitrosamine level detected rising with increasing acidity and increasing dimethylamine and nitrite concentrations. Dimethylnitrosamine also appears in sewage and lake water samples receiving trimethylamine. Microorganisms are involved in some stage of the conversion of the tertiary amine to the secondary amine and dimethylnitrosamine in sewage because these products are not found in sterilized sewage. The fungicide thiram (tetramethylthiuram disulfide) is converted to dimethylamine in sterilized sewage at pH 4.0, and small amounts of dimethylnitrosamine are also produced in the presence of nitrite; the yields of both products are far greater in nonsterile, thiram‐amended sewage. The identification of dimethylnitrosamine was verified by thin‐layer and gas chromatography, ultraviolet and infrared spectrometry, and combined gas chromatrophy‐mass spectrometry.
Methylmercury Formation in Mercury‐Treated River Sediments During in situ Equilibration
Authors: Jacobs L. W. , Keeney D. R. 
Published: July 2010

AbstractAn in situ experiment was established at two environmentally different river sites (one each on the Wisconsin and Fox rivers) to evaluate the extent of methylmercury (MeHg) production in and Hg loss from sediments treated with mercuric chloride (HgCl2) or phenylmercuric acetate (PhHgAc). Bulk sediment was collected from each river site, treated with approximately 1, 10, or 100 ppm Hg (oven‐dry basis) as HgCl2 or PhHgAc, and returned to the river site with untreated controls for 2, 4, or 12 weeks of equilibration with the aquatic environment. After each sample retrieval, the sediments were analyzed for total Hg using an aqua regia digest and flameless atomic absorption spectrophotometry and for MeHg by gas chromatography using a modified extraction procedure which is described.Results suggest that Hg losses from stationary sediments are minimal and that sediment transport is probably the major source of Hg movement in a river system. In both sediments, more MeHg was produced from PhHgAc than from a similar concentration of HgCl2, and MeHg concentration increased as the Hg treatment with either compound was increased. The MeHg concentrations found in the Wisconsin River sediments were substantially higher than in the Fox River sediments with a similar Hg treatment. The large differences in MeHg production between these two sediments may be partially attributed to their chemical dissimilarities. The Wisconsin River sediment is acidic and contains more organic materials compared to the Fox River sediment which is more alkaline and contains larger amounts of sulfide sulfur.
Nitrogen Content of Shallow Ground Water in the North Carolina Coastal Plain
Authors: Gilliam J. W. , Daniels R. B. , Lutz J. F. 
Published: July 2010

AbstractThe NO3‐N and NH4‐N concentrations in shallow (< 3 m) ground water under a range of soil types, drainage conditions, and type of crop grown were monitored. The NO3‐N levels were always low (1 ppm or less) in ground water under wooded areas. The concentrations were somewhat higher under cultivated fields with the levels usually being 1 to 5 ppm although several values in the range of 10 to 20 ppm were recorded. The concentrations in all wells were always higher during the winter months. There seemed to be no relationship between cultivated crop and NO3‐N in the ground water. The NO3‐N concentration was almost always higher in the middle of the field than on the edge of the field even though the direction of water flow was toward the edge of the field. It is suggested that denitrification is responsible for this decrease.There was little difference in NH4‐N concentration in water under cultivated fields and under unfertilized woods or pasture. The NH4‐N concentrations were normally in the range of 0.1 to 1 ppm with the higher levels being found under poorly‐drained soils.Based upon the characteristics of the surface sediments, it is concluded that very little of the NO3‐N present in the shallow ground water moves into deep aquifers in any area of the North Carolina Coastal Plain. However, the amount of NO3‐N that moves through the surficial sediments to the streams probably varies with location and characteristics of the confining beds.
Erosional Losses of s‐Triazine Herbicides
Authors: Hall J. K. 
Published: July 2010

AbstractErosional losses of two chloro‐s‐triazines, atrazine and GS13529, were evaluated in 1970 and 1971 from field runoff plots planted to corn (Zea mays L.) and situated on an Hagerstown silty clay loam of 14% slope. Losses of a methoxy‐s‐triazine, GS14254, were assayed in 1971 and 1972 from an alfalfa (Medicago sativa L.) stand. Herbicides were applied preemergent to corn and to dormant alfalfa only once during the initial growing season or initial season of evaluation at two rates, 2.2 and 4.5 kg/ha. Total losses of atrazine during the first and most critical season at the respective rates were 5.0 and 4.8% of that applied and 87 to 93% of this loss resulted within the first month following application. Total losses of the related chloro‐s‐triazine were comparable at each of the rates. Both of these compounds dissipated at a moderate rate over the growing season with GS13529 showing a higher level of recalcitrance, particularly early in the season. Soil core analysis revealed that one month after application an average of 35.3% of the applied atrazine was recovered; five months later an average level of 11.8% was residual. Recovery of GS13529 ranged from 62.5 to 9.8% for the same time period.Runoff losses of GS14254 from alfalfa were inconsequential. Little runoff was obtained from this cropping system, no sediment was ever collected and runoff concentrations of the herbicide were extremely small. Total losses of this herbicide for the year were 0.02 and 0.03% for the respective application rates.Actual losses of water and soil to runoff in 1970 appeared to be of a more critical nature than chemical losses. Runoff losses during one particular erosion event ranged from 17% of the incident rainfall for the check plot to 68% at the low rate of atrazine. Moreover, 9800 kg/ha (4.4 tons/a) of soil were lost at the low rate. These kinds of results speak strongly for sound soil and crop management practices and conservation measures on sloping cropland.
Field Study of Solute Movement in a Highly Aggregated Oxisol with Intermittent Flooding: II. Picloram
Authors: Rao P. S. C. , Green R. E. , Balasubramanian V. , Kanehiro Y. 
Published: July 2010

AbstractMost of the applied herbicide picloram (potassium salt of 4‐amino‐3,5,6‐trichloropicolinic acid) was retained in the top 40‐cm depth of the Molokai soil with cumulative applications of 48 to 74 cm water following application of the chemical to the soil surface. Distribution of picloram in the soil profile one week after each irrigation was determined by in situ sampling of soil solution with porous ceramic cups placed at several depths. Although movement of the picloram peak was retarded more than was anticipated from equilibrium adsorption measurements, a significant fraction of the applied herbicide moved ahead of the peak deep into the profile (down to the 143‐cm depth) after a single application of 24‐cm water. Rapid flow through macropore sequences combined with temporary retention of picloram in aggregate micropores appear to be responsible for the unusual pattern of movement. Published data for nitrate movement in the same field plots of Molokai soil were compared with picloram movement data to provide a measure of the relative mobility of these solutes. A comparison of the results reported here with published field data of solute leaching in other soils indicated a greater retardation of solute peak movement in Molokai soil than in less aggregated soils.
Respirometric Evidence of the Utilization of Di‐octyl and Di‐2‐ethylhexyl Phthalate Plasticizers
Authors: Mathur S. P. 
Published: July 2010

AbstractPhthalic acid esters (PAEs), due to their teratogenic and mutagenic properties, threaten to disturb the ecological balance. Di‐octyl phthalate (DOP) and di‐2‐ethylhexyl phthalate (DEHP) esters are present in the environment as micropollutants, originating from industrial usages in plastics.Because of the probability that PAEs also occur naturally, it was expected that soil and water microorganisms would utilize PAEs during the performance of their normal role in the cyclization of carbon in nature.Since this assumption is not sufficiently supported in the literature, a study was conducted to determine whether soil microorganisms utilize DOP and DEHP. A loam soil was incubated at 4, 10, 22 to 25 and 32C with DOP, DEHP and two other PAEs. Soil respiration rates were measured after 14 weeks, either with or without fresh additions of the PAEs. Increased rates of respiration, indicating microbial utilization of all the PAEs, were recorded. However, the results indicated that DOP and DEHP are used only marginally at 4 and 10C.