bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrate and Chloride Accumulation and Distribution in Fertilized Tile‐Drained Soils
Authors: Gast R. G. , Nelson W. W. , MacGregor J. M. 
Published: July 2010

AbstractResults of long term continuous corn studies on tile drained Webster loam in southwest Minnesota show that annual N applications up to 70% greater than N removed in grain are required for maximum yields. The object of the reported study was to establish the relative role of N incorporation into the soil organic matter and/or losses through denitrification, downward leaching, or tile drainage in determining the fate of this fertilizer‐N added above that removed in corn grain. Nitrate and chloride accumulations and distributions were determined in a Webster loam and Waldorf silty clay loam profiles after long term fertilization for continuous corn. Concentrations in the profiles were determined at 0.3 m depth intervals and at increasing distances from tile lines.Maximum NO3−‐N accumulations accounted for less than half of the fertilizer‐N added but unrecovered in the corn grain. In contrast, Cl− accumulations in the soil profiles were approximately equal to that added, with little or no effect of distance from tile lines on either amounts present or on profile distribution: i.e. there was relatively little Cl− loss through tile drainage. Assuming Cl− and NO3− move with water at about the same rate, the results further suggest minimal loss of NO3−‐N in tile drainage. Since Cl− and NO3− concentration are small at depths greater than 3 m, downward leaching losses are apparently minimal leaving denitrification and/or incorporation into organic matter as the mechanisms largely responsible for disappearance of the unused fertilizer‐N. Denitrification is probably the main factor involved since similar experiments on well‐drained Minnesota soil showed little net incorporation of N into organic matter.
Effect of Nitrate and Sediment Constraints on Economically Optimal Crop Production
Authors: Onishi H. , Swanson E. R. 
Published: July 2010

AbstractCrop systems and practices which are economically optimal in a 485.6‐ha (1,200‐acre) watershed with a planned recreational reservoir were determined under conditions of varying constraints on water quality in the reservoir. The technique of linear programming was used. Two requirements related to sedimentation and three requirements related to NO3−‐N concentration in the leachate below the root zone were considered. Thus, six combinations of restrictions on the choice of optimal crop systems were imposed. A system of charges for all sediment introduced into the reservoir substantially reduced erosion, irrespective of the limit placed on NO3−‐N concentration in the leachate below the root zone. Relaxation of the NO3−‐N limit from 10 mg/liter to no limit approximately doubled the net income above nonland costs.
Uptake of Inorganic Mercury by Bed Sediments
Authors: Kudo Akiro , Hart J. Sanford 
Published: July 2010

AbstractThe kinetics of uptake of inorganic mercury as mercuric chloride by a variety of freshwater river sediment types typical of Ottawa River sediments were studied to determine the influence of mercury concentration in water, hydrodynamic effects, sediment depth, aerobic or anaerobic conditions, and two types of water. Uptake appears to depend strongly on concentration of mercury in water and water velocity, and not on sediment depth or water type. No significant difference in uptake rates was observed between aerobic and anaerobic conditions during the 10 days studied.
Decomposition in Soil of Waste Cooking Oils Used in Potato Processing
Authors: Smith J. H. 
Published: July 2010

AbstractCooking oils used in potato processing are sometimes wasted in small quantities into the effluent that goes to land disposal. To determine the effect of this oil on land, palm and soybean oils were added to Portneuf silt loam at rates of 0.1, 0.5, 1.0, and 5.0 g oil in 100 g soil (2.2, 11.2, 22.4, and 112 metric tons/ha, respectively). Nitrogen was added and the mixtures were incubated at constant temperature in a CO2‐free continuously flowing air stream. Evolved CO2 was scrubbed from the air stream and decomposition calculated. Both oils decomposed at the same rate at each application rate. Maximum weekly decomposition was approximately 8 and 2.5 metric tons/ha for the 112 and 11.2 metric ton‐applications, respectively. There was no evidence for toxicity to the decomposition systems with the high application of oil and no evidence that difficulty would develop with land disposal of wastes containing these edible cooking oils.
Determination of Trace Metals in Sodium Dithionite‐Citrate Extracts of Soils and Sediments by Atomic Absorption
Authors: Jenne E. A. , Ball J. W. , Simpson C. 
Published: July 2010

AbstractA general method has been developed for the analysis of Co, Cu, Ni, Mo, and Zn in dithionite‐citrate extracts of soils and sediments. Because of the high Zn content of dithionite, it is necessary to preclean the dithionite‐citrate solution before it is used to extract soils or sediments. This precleaning lowers the detection level significantly for other trace elements as well. Since Fe causes flame interferences in the determination of several first transition series elements by atomic absorption, the size of the individual sample aliquot taken to chelation‐solvent concentration is varied to provide a constant quantity of Fe (5,000 µg). The standards and blanks are adjusted to the same Fe content. This approach is necessitated by the wide differences in the Fe concentrations of the dithionitecitrate extracts. Following pH adjustments and addition of ammonium‐1‐pyrrolidine dithiocarbamate, the trace metals (and Fe) are concentrated via two successive 10‐ml methyl isobutyl ketone extractions. Quantities of Fe much greater than 5,000 µg interfere in the solvent concentration step. Natural organics released by the dissolution of free‐Fe and ‐Mn oxides, to the extent that they are represented by fulvic acids, do not cause any significant interference in the ammonium‐1‐pyrrolidine dithiocarbamate methyl isobutyl ketone extraction of the trace metals due to the releasing effect of the Fe present.
Phosphorus Associated With Sediments in Irrigation and Drainage Waters for Two Large Tracts in Southern Idaho
Authors: Carter D. L. , Brown M. J. , Robbins C. W. , Bondurant J. A. 
Published: July 2010

AbstractPhosphorus was measured in irrigation and surface drainage waters for two large irrigation tracts, and inorganic, water‐soluble PO4‐P and total P inputs and outputs were computed. The present irrigation practices on both irrigation tracts conserve P by removing more P from the Snake River in irrigation water than is returned in drainage water. Even greater P conservation could be attained by implementing new practices. Approximately 90% of the P in waters diverted to irrigate the Northside Tract remained in the tract. About 50% of the amount diverted remained in the Twin Falls Tract. Particle size segregation takes place in some drainage streams and the finer sediments returning to the river contain higher total and NaHCO3‐extractable P concentrations than the soils from which they were eroded. The importance of defining sampling methods and procedures for P analyses is illustrated by comparative data on irrigation and drainage waters. The PO4‐P concentration in samples filtered through a 0.45 µm membrane filter was independent of the sediment concentration in waters, whereas the total P concentration of unfiltered samples was proportional to the sediment concentration.
Sediment in Irrigation and Drainage Waters and Sediment Inputs and Outputs for Two Large Tracts in Southern Idaho
Authors: Brown M. J. , Carter D. L. , Bondurant J. A. 
Published: July 2010

AbstractSediment inputs from Snake River irrigation water and sediment losses back to the river were measured for two large irrigated tracts in southern Idaho. There was a net sediment accumulation of 0.69 metric tons/ha onto the 65,000 ha Northside tract but a net sediment loss of 0.46 metric tons/ha from the 82,000 Twin Falls tract. Differences in sediment losses from the two tracts result from the difference in sedimentation in the drain‐ways of the two projects. Sediment deposited in drains on the Northside tract amounted to 4.5 metric tons/ha compared to 0.95 metric tons/ha for the Twin Falls tract. Drains on the Northside tract were constructed to grade whereas most drains on the Twin Falls tract are natural channels with steeper gradients. The net amounts of sediment eroded from farms within each tract were 4.0 metric tons/ha for the Northside tract and 1.42 metric tons/ha for the Twin Falls tract. This erosion loss from farms could be reduced within each tract by more careful use of water and construction of on‐farm sediment retention ponds. This would also reduce the amount of sediment returned to the river and lower costs of mechanically removing sediment from drains and canals. Construction of sediment retention ponds along main drains and reducing the amount of surface runoff returning to the river would also reduce the amount of sediment returning.
Ground‐Water Quality Related to Irrigation with Imported Surface or Local Ground Water
Authors: Nightingale H. I. , Bianchi W. C. 
Published: July 2010

AbstractGround‐water quality in an arid irrigated area that imports high quality surface water was compared with an adjacent up‐gradient area that uses local pumped ground water. A large irrigation canal separates the two areas which are up‐gradient from the pumping depression of the Fresno‐Clovis, California metropolitan area, which is dependent on ground water. Intensive sampling (154 wells) was done in the fall of 1972 after it was shown by previous sampling that the ground‐water electrical conductivity (EC), NO3−, and Cl− content had not significantly changed since 1967. Diagrammatic distribution maps for ground‐water quality showed great variability. The Wilcoxon‐Mann‐Whitney nonparametric statistical tests showed the significance probabilities for EC, NO3−, and Cl− differences above and below the canal were 0.093, 0.114, and < 0.00006, respectively. The significance of these differences are determined by the reader or decision‐maker by his chosen error probability, the error risk he is willing to take in rejecting the null hypothesis of no difference when it is true. Areas of higher ground‐water NO3− and Cl− were generally related to soil drainage‐recharge and agricultural use. The use of local ground water without supplemental surface supplies above the canal has led to ground‐water EC, NO3−, and Cl− concentrations to be 9.5, 18.6, and 91.8% higher, respectively, than below the canal which uses mostly high quality surface water.
Barriers to the Foliar Uptake of Lead
Authors: Arvik Jon H. , Zimdahl Robert L. 
Published: July 2010

AbstractCuticles of leaves and fruits were studied to determine the ability of these structures and their waxes to prevent movement of lead into the plant. Only extremely small amounts of lead could penetrate the cuticles, even after extended exposure. Removal of the waxes permitted increased penetration of some cuticles, and penetration seemed more related to species of plant than to thickness of the cuticle. Additionally, living plants were challenged by aerosols of lead bromochloride in an exposure chamber. Virtually all of the lead added to plants in this manner could be removed by chloroform rinse or mild acid washes, suggesting that the lead remained as a topical coating on the foliage. No significant amount of lead could be found in roots, fruit, or new shoot growth following exposure to lead aerosols.
A Simulation Model for Prediction of Herbicide Persistence
Authors: Walker Allan 
Published: July 2010

AbstractA simulation model for prediction of herbicide persistence in the field is described. The model combines the effects of soil temperature and soil moisture content on the rates of herbicide loss, determined experimentally under controlled conditions, with the fluctuations in surface soil temperature and moisture content in the field. The computer program includes methods of simulating surface soil temperatures and moisture contents from standard meteorological data. In order to test the model, the degradation of napropamide (2‐(a‐naphthoxy)‐N,N‐diethylpropionamide) was examined. Under controlled conditions, loss of activity followed first‐order kinetics with half‐lives of 54, 63, and 90 days at 28C with soil moisture contents of 10.0, 7.5, and 3.5%, respectively. At 14C, half‐lives at 10.0 and 7.5% soil moisture were 102 and 112 days, respectively. When these data were used in the simulation model in conjunction with the relevant meteorological information, the patterns of loss of napropamide incorporated 2 to 3 cm in the field could be predicted. Napropamide was lost rapidly when applied to the soil surface, and since the model only takes into account losses through microbial or chemical metabolism, this could not be simulated. Some of the limitations and the potential benefit of the simulation technique for prediction of pesticide persistence are discussed.
The Effects of SO2 on in vitro Forest Tree Pollen Germination and Tube Elongation
Authors: Karnosky David F. , Stairs Gerald R. 
Published: July 2010

AbstractThe effects of SO2 on in vitro pollen germination and tube elongation were examined for Populus deltoides (Bartr.), Pinus resinosa (Ait.), Pinus nigra (Arnold), and Picea pungens (Engelm.). Comparisons were made between pollen fumigated in a dry condition and then placed on the germinating media, and moist pollen fumigated while on the germinating media.Moist P. deltoides pollen germination was significantly reduced at SO2 concentrations of 0.75 ppm and above. Populus deltoides pollen tube elongation was more sensitive to SO2 exposure and highly significant decreases in tube length occurred at 0.30 ppm for 4 hours. Tube elongation decreased linearly with increases in SO2 concentration. Frequent bursting of pollen tubes occurred at SO2 concentrations greater than or equal to 0.3 ppm for 4 hours.Exposure to SO2 caused similar effects on pollen germination and tube elongation for Pinus resinosa, Pinus nigra, and Picea pungens. Moist pollen was far more sensitive than dry pollen to SO2 exposure. A 4‐hour exposure to 1.4 ppm SO2 severely restricted moist pollen germination and tube elongation of the three conifer species. However, a similar exposure to 10 ppm SO2 had no effect on dry pollen of the three species.Absorption of SO2 resulted in an acidification of the germination media. Germination trials on acidified media indicated that the resultant acidification could account for much of the reduced germination and tube elongation in P. deltoides but could not adequately explain the reduced conifer pollen germination and tube elongation.
Movement of Coliform Bacteria from Septic Tank Effluent through Selected Coastal Plain Soils of Virginia
Authors: Reneau R. B. , Pettry D. E. 
Published: July 2010

AbstractMovement of total and fecal coliform bacteria form septic tank effluent through three Virginia Coastal Plain soils was monitored in situ over a 2‐year period. These soils were considered to be marginally suited for sanitary disposal of domestic wastes because of fluctuating seasonal water tables and/or restricting layers. Since septic effluent moved predominantly in a horizontal direction in these soils as a result of slowly permeable subsurface horizons, series of piezometers were installed to collect samples at selected distances and depths from the source (subsurface drainfield) in each of the soils studied. Generally, the most‐probable‐numbers (MPN) of both total and fecal coliforms decreased significantly with horizontal distance and depth. At the Varina location total and fecal coliform counts were observed to decrease from 11 and 1.3 × 106/100 ml in the distribution box to 11 and 2.5 × 103/100 ml at 6.1 m, respectively, above a relatively impermeable plinthic horizon. At the Goldsboro and Beltsville sites large reductions in both total and fecal coliform counts were noted within 13.5 m. Few detectable fecal coliform were present below the restricting layers at all three sites. On the basis of these results, it seems unlikely that coliform bacteria would move into the permanent ground water system.
Suspended Solids Carried by the Gallatin River of Southwestern Montana: II. Using Mineralogy for Inferring Sources
Authors: Klages M. G. , Hsieh Y. P. 
Published: July 2010

AbstractSilt and clay carried in suspension by a mountain river in southwestern Montana were examined by X‐ray diffraction. Suspended sediment samples were collected from the river and its tributaries during spring snowmelt. In general the mineralogy of the sediment was related to geology of the drainage area but also differed between streams from similar geologic materials. Quartz gave the dominant diffraction peak in silts and smectite in clays from most of the streams. One tributary, Taylor Fork, was identified as the the chief source of suspended solids. The mineralogy of its silt and clay resembled that carried by the river on 8 of 10 sampling dates. Erosion of alluvial materials from the lower valley produced sediment with mineralogy similar to that presently carried by the river suggesting that the source of sediment has not changed much in recent geologic time. Branches of the tributary contributing the most sediment and of one other large tributary were examined. The branch contributing the most silt and clay to each could be identified from mineralogical measurements. An attempt to use crystallinity to determine if clays were eroded from surface soils was only partly successful.
Weathering of Accumulated Wastes in Unroofed and Unpaved Confined Livestock Operations
Authors: Chang A. C. , Adriano D. C. 
Published: July 2010

AbstractTwo unpaved outdoor livestock confinement units in southern California were sampled to determine the weathering and accumulation pattern of wastes on the ground surface after 2 months of waste accumulation. The result indicated that animal waste tended to accumulate in certain parts of the confinement area. It was found approximately 50% of the total waste produced was concentrated in 25% of the surface area. During the period of accumulation, waste underwent a 10–15% reduction of total solids apparently due to biological decomposition. The prevailing dry climate in the region has also limited the problem of waste accumulation to essentially that of odors and dusts. However, the samples collected indicated the accumulating waste was unstable and would undergo further decomposition at a suitable environmental condition. Moisture content, chemical oxygen demand, total nitrogen and chloride content of the waste samples were also determined. There appeared to be little difference in the weathering of accumulated wastes because of management operations at the two confinement units.
Effect of Sewage Sludge on Some Soil Physical Properties
Authors: Epstein Eliot 
Published: July 2010

AbstractRaw and digested sewage sludges, 5% by weight, were incorporated into a Beltsville silt loam soil. The soil‐sludge mixtures were incubated at 15, 25, and 35C for 75 days. Periodic measurements were made on water retention, hydraulic conductivity, and aggregate stability. Adding sewage sludge shifted the water retention curve so that the water content at specific water potential values was higher, but the amount of water between −0.33 and −15 bars potential essentially remained the same as that of the original soil.Addition of sewage sludge initially increased the saturated hydraulic conductivity. After 50 to 80 days, however, the hydraulic conductivity dropped to that of the original soil. Percent stable aggregates increased as a result of sludge addition. After 175 days, the percent stable aggregates averaged 28–35% for the sludgeamended soil, as compared to 17% for the original soil.
Effects of an Organic Arsenical Herbicide on a Salt Marsh Ecosystem
Authors: Edwards A. C. , Davis D. E. 
Published: July 2010

AbstractThe effects of single and repeat applications of monosodium methanearsonate (MSMA) on the standing crops of smooth cordgrass (Spartina alterniflora L.), a periwinkle (Littorina irrorata Say), and a rib mussel (Modiolus demissus Dillwyn) were investigated. Treatments applied were as follows: (i) single foliar application 90,000 ppm; (ii) 30 foliar applications of either 10,000, 1,000, 100, 10, or 0 ppm; and (iii) 30 floodings of enclosed areas of the salt marsh with 100 or 0 ppm MSMA. Post‐treatment sampling revealed: (i) no treatment altered the density of smooth cordgrass; (ii) 30 applications of 10,000 ppm decreased the dry weight living smooth cordgrass; (iii) flowering shoot production was reduced by 30 applications of 10,000 or 1,000 ppm; (iv) one application of 90,000 ppm and 30 applications of 10,000 or 1,000 ppm increased the percentages of dead and necrotic tissue on living shoots of smooth cordgrass and; (v) the periwinkle population was decreased by 30 applications of 10,000 ppm. None of the other treatments showed any significant effects on these parameters. Survival of the rib mussel was apparently not affected by flooding with 100 ppm in sea water. Arsenic levels in smooth cordgrass and soil samples were significantly increased by 30 foliar applications of 10,000 ppm or flooding 30 times with 100 ppm. Arsenic levels in periwinkles and rib mussels also increased immediately following these treatments with MSMA.
Metal Uptake by Barley Seedlings Grown on Soils Amended with Sewage Sludge
Authors: Dowdy R. H. , Larson W. E. 
Published: July 2010

AbstractThe removal of metals by 30‐day‐old barley seedlings (Hordeum vulgare L., cv. Traill) from two topographically associated soils having pH's of 5.9 and 7.9 (free carbonates) was studied following the application of 0, 3.8, 7.6, 15.2, and 30.4 tonne/ha of sewage sludge. One set of soil‐sludge samples were incubated for 1‐growing‐degree year before cropping to study the effect of sludge degradation on metal availability.Total uptake of Zn, Pb, Ni, and Cr was greater from the sludge‐amended acid soil than from the calcareous soil. Incubation resulted in greater removal of Zn, Pb, Ni, and Cr from the acid soil. For the alkaline soil, incubation increased Cr uptake, but had no effect on Zn, Pb, Cu, and Ni uptake. In general, with the exception of Cu, metal uptake was greater from the incubated, acid soil‐sludge mixture than from a comparable nonincubated or alkaline mixture.Sludge applications did not affect the amount of Ca and Mg extracted, but increased Na uptake. Conversely, the Ca and Mg concentration in barley tops decreased as the Na concentration increased with added sludge. The Fe concentration in the leaf tissue of seedlings grown on the acid soil was greatly depressed by the application of 30 tonne/ha of sewage sludge.