bluuebunny/crossref_metadata_2025_split huggingface dataset:
Insect Damage, Aspergillus flavus Ear Mold, and Aflatoxin Contamination in South Georgia Corn Fields in 1977
Authors: McMillian W. W. , Wilson D. M. , Widstrom N. W. 
Published: July 2010

AbstractA survey of preharvest corn (Zea mays L.) in 31 counties in the Coastal Plain Region of Georgia suggested that ears molded by Aspergillus spp. of the Aspergillus flavus group and ears damaged by insects were widespread in about 810,000 ha (2 mllion acres) of corn grown in the area. Ninety percent of the field‐collected samples contained aflatoxin in excess of 20 µg/kg. Averagear damage by insects ranged from a low of 1.4 cm to a high of 8.9 cm. Highly significant correlations were found between insect damage and percentage of ears with visible A. flavus ear mold, between insect damage and aflatoxin contamination, and between percentage of ears with visible A. flavus ear mold and aflatoxin contamination.
Nitrogen and Phosphorus Losses from Organic Soils
Authors: Duxbury J. M. , Peverly J. H. 
Published: July 2010

AbstractThe nutrient content of drainage water from Histosols located in New York was monitored from June 1975 through July 1977. Continuous flow records and nutrient concentration data obtained from daily composite samples were used to calculate annual nutrient outputs which ranged from 0.6 to 30.7 kg/ha for PO4−‐P, 39.2 to 87.5 kg/ha for NO3−‐N, and <1.0 to 1.9 kg/ha for NH4+‐N. Nutrient concentrations in the drainage water increased with increasing flow, so that the greatest output of nutrients was during late winter and spring high‐flow events. Maximum observed concentrations were 35 mg/liter for NO3−‐N and 10 mg/liter for PO43−‐P.The amount of N lost in drainage water was similar at all sites and was about 10% of that mineralized; the remainder was presumed to be denitrified. The fiftyfold variability in phosphorus output appeared to be related to interactions within the soil profile rather than fertilizer practices, although these probably contributed to the generally high levels found. It was concluded that fertilizer nitrogen additions were unlikely to affect the quantity of NO3− leached.The study showed that organic soils can contribute to N and P in land runoff in much greater proportions than indicated by their area.
Redox Potentials in a Cropped Potato Processing Waste Water Disposal Field with a Deep Water Table
Authors: Smith J. H. , Gilbert R. G. , Miller J. B. 
Published: July 2010

AbstractRedox potential measurements were made in a field irrigated with potato processing waste water at seven depths of 5 to 150 cm for 14 mo. Irrigation with canal water mixed with waste water in the summer, and with waste water in the winter, decreased redox potentials in the field at some depths for a short time but not enough to cause denitrification. However, as the soil temperature increased in the spring, and decomposition of the accumulated waste organic matter accelerated, redox potentials decreased after each irrigation at all observed depths. During April, redox potentials low enough to promote denitrification (below +225 mV) at 90‐, 120‐, and 150‐cm depths in the soil persisted for 2 weeks. Irrigation with nondiluted waste water in June and July decreased redox potentials and denitrification occurred for up to 3 days after irrigations. As the soil temperature increased in the spring, nitrification of accumulated organic matter increased soil nitrates. Waste water irrigations from April to July promoted denitriflcation, removing most of the nitrate from the soil, and thereby decreasing the potential for ground water pollution.
Simazine Residue Levels in Irrigation Water after Ditchbank Application for Weed Control
Authors: Anderson Lars W. J. , Pringle John C. , Raines Roger W. , Sisneros David A. 
Published: July 2010

AbstractA field study was conducted to determine the amount of simazine [2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine] likely to be found in irrigation water after ditchbank treatment for weed control. Resulting data are useful in evaluating the potential impact of simazine on crops irrigated from sprayed canals. Canals were selected in California, Colorado, and Washington for the application of simazine to both watered and dewatered sites at rates of 2.25 to 7.43 kg/ha. Simazine levels in flowing canal water immediately after herbicide application did not exceed 60 µg/liter. In first‐flow samples collected in the spring from the sites that were dewatered at application, simazine levels peaked at about 250 µg/liter within the treated section but decreased rapidly to <5 µg/liter.
Bromacil in Lakeland Soil Ground Water
Authors: Hebb Edwin A. , Wheeler Willis B. 
Published: July 2010

AbstractThe objective of this study was to evaluate the probable magnitude of the problem of the leaching of pesticides into ground water under extreme conditions: a sandy soil low in organic matter, a persistent and mobile herbicide applied at a high rate, plentiful rainfall, and a water table within 6 m. Bromacil (5‐bromo‐3‐sec‐butyl‐6‐methyluracil) was applied at the rate of 22 kg/ha to a Lakeland sand bearing scrub vegetation of small oaks and poor grasses. Ground water (at depths ranging from 4.5 to 6 m) was sampled from bromacil residue at weekly intervals for 2 years. Residue was first found in the ground water 3 mo after application and was highest (1.25 ppm) 1 month later. Thereafter the amount declined to <0.1 ppm in about a year and <0.001 ppm in 2 years. Peaks in residues generally followed periods of increased rainfall by about 2 weeks. Residues (0.24 ppm) were still detected in the surface soil 2 years after application.
The Role of Insects and Other Plant Pests in Aflatoxin Contamination of Corn, Cotton, and Peanuts—A Review
Authors: Widstrom N. W. 
Published: July 2010

AbstractThe relationship of insects to certain fungi and moldy agricultural commodities has received special attention in the last several years since it was determined that some of the fungi produce aflatoxin and other toxic metabolites. These fungi and their toxic by‐products have been suggested for use as insecticides, as a source of stable chemosterilants, and as potentially effective biological control agents for various insect species. The principal role of the insect in the toxin contamination of agricultural commodities is believed to be one of predisposing plant tissue to invasion by the fungus. The European corn borer, Ostrinia nubilalis (Hübner), the corn earworm, Heliothis zea (Boddie), and the fall armyworm, Spodoptera frugiperda (J. E. Smith), have been identified as the major insects implicated in Aspergillus flavus infection and subsequent aflatoxin contamination of preharvest corn (Zea mays L). The pink bollworm, Pectinophora gossypiella (Saunders), and, to a lesser extent, the boll weevil, Anthonomus grandis Boheman, appear to be influential in predisposing cotton (Gossypium hirsutum L.) and cotton seed to A. flavus infection. The available literature does not provide conclusive evidence to positively link the pests of peanuts (Arachis hypogaea L.) with aflatoxin contamination of that crop. Therefore, insect control is expected to be less helpful in solving the aflatoxin contamination problem on peanuts than on corn or cotton.
Persistence of Carbofuran and its Metabolites, 3‐Keto and 3‐Hydroxy Carbofuran, under Flooded Rice Culture
Authors: Deuel L. E. , Price J. D. , Turner F. T. , Brown K. W. 
Published: July 2010

AbstractPesticides are essential for the economical production of rice in the Gulf Coast region of Texas, since weeds and insects could severely damage the crop if uncontrolled. However, water quality of surface impoundments and estuaries interspersed in close geographic proximity to the rice belt could be adversely affected by pesticide loading via irrigation return flow.Field experiments were conducted under flooded rice (Oryza sativa L.) culture to evaluate residual levels of carbofuran (2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl‐N‐methyl carbamate), 3‐keto carbofuran (2,3‐dihydro‐2,2‐dimethyl‐3‐keto‐7‐benzofuranyl‐N‐methyl carbamate), and 3‐hydroxy carbofuran (2,3‐dihydro‐2,2‐dimethyl‐3‐hydroxy‐7‐benzofuranyl‐N‐methyl carbamate). Treatments consisted of two rates of carbofuran (0.56 and 3.35 kg/ha) superimposed two irrigation management schemes (intermittent and continuous flow).Results of the 3‐year field and laboratory study suggested that carbofuran was dissipated from the plot water via an adsorptive mechanism. Carbofuran applied at the recommended rate was generally dissipated within 96 hours following its infusion into the plot water. The evaluation of carbofuran persistence was complicated by surges in plot water values corresponding to rainfall events, although statistically significant quantities remained for longer periods of time in those plots which had received the excessive application rate. Irrigation management was not a significant source of variation once values were normalized to account for the variable plot water depths. Neither 3‐keto nor 3‐hydroxy carbofuran were detected in excess of 0.001 kg/ha at the recommended application rate.
Distribution Gradients of Arsenic, Copper, and Chromium around Preservative‐Treated Wooden Stakes
Authors: DeGroot R. C. , Popham T. W. , Gjovik L. R. , Forehand T. 
Published: July 2010

AbstractThe distribution gradients of arsenic and chromium in soil around and below nominal 50‐ by 101‐mm (2‐ by 4‐in) southern pine stakes that were treated with either chromated copper arsenate (CCA Type I or Type II) or in ammoniacal copper arsenate (ACA) and exposed nearly 30 years in Poarch fine sandy loam soils in southern Mississippi indicate that the small amounts of As and Cr that move from the stakes into the soil are sorbed by the soil proximal to the stakes. The distribution gradient for copper about the stakes is similar to those for As and Cr, but is less precise. These findings support the hypothesis that CCA‐ and ACA‐treated wood, at least in acidic soils such as the Poarch fine sandy loams, will not contribute significant amounts of As or Cr into surrounding soils and waters.
Metal Content of Plants and Soils in a Tree Nursery Treated with Composted Sludge
Authors: Korcak R. F. , Gouin F. R. , Fanning D. S. 
Published: July 2010

AbstractDigested sewage sludge compost from Washington, D.C., was applied to a Downer sand at rates of 0, 56, 112, 224, and 448 dry metric tons/ha. A fertilized control treatment was also utilized. Pearl millet (Pennisetum americanum [L.] K. Schum.) was grown as a summer cover crop prior to fall tree seeding. Leaf samples of red oak (Quercus ruba L.) and black walnut (Juglans nigra L.) seedlings were taken the summer of the first growing season. The total metal contents (µg/g) of the compost were 2,154 Zn, 517 Cu, 13.9 Cd, and 69 Ni. The treated soils were monitored for DTPA extractable Zn, Cu, Cd, and Ni throughout the 2.4 years of the experiment.No visual, foliar effects were noted on the growth of pearl millet or tree seedlings from the increasing rates of compost, however, pearl millet tissue Cd levels were significantly increased with increasing levels of compost from about 0.40 to about 1.62 µg/g. Metal contents of the tree seedlings were low and within normal levels recorded in the literature. Extractable soil Zn, Cd, and Cu decreased with time, however, soil Ni extractability tended to increase with time. Compost additions resulted in an increased soil pH which was maintained throughout the experiment.Poor correlations (r2 ranged from 0.002 to 0.543) were obtained between DTPA extractable metals and metal concentrations of pearl millet, red oak, or black walnut.
Inorganic Nitrogen and Soluble Salts in a Davidson Clay Loam used for Poultry Manure Disposal
Authors: Weil R. R. , Kroontje W. , Jones G. D. 
Published: July 2010

AbstractThe logistics of handling poultry manure often dictate that it be spread on land near to its source at rates far in excess of what would constitute its efficient use as fertilizer. This study measured, at various times during the growing season, the concentrations of soluble salts, ammonium, nitrates, and nitrites in the upper horizons of a common Piedmont soil which had received yearly up to 100 metric tons of poultry manure per ha for 5 years. During spring and summer, concentrations of soluble salts (up to 4,064 ppm) and nitrite‐N (up to 60 ppm) were high enough to be toxic to corn (Zea mays, L. cultivar Pioneer 3369A). Ammonium‐N was detected at up to 800 ppm in April, but decreased to less than 100 ppm by July. Both stand establishment and subsequent growth of corn were very poor on the heavily manured plots. As seedlings, corn plants on these plots exhibited burned leaf tips and margins and stunted root growth associated with high levels of ammonia, nitrites, and total soluble salts. Severe moisture stress was evident throughout the growing season due to the effects of salinity and stunted root systems. Rapid leaching of salts and nitrates did not take place until after September. Denitrification appeared to be responsible for some losses of nitrates. Despite the accumulation of nitrites, especially in May and July, most probable number determinations failed to show any consistent inhibition of the populations of Nitrosomonas and Nitrobacter.
The Movement of Fecal Coliforms and Coliphages below Septic Lines
Authors: Brown K. W. , Wolf H. W. , Donnelly K. C. , Slowey J. F. 
Published: July 2010

AbstractA 2‐year lysimetric study utilizing three undisturbed soils was conducted to investigate the movement of fecal coliforms and coliphages to the ground water. Septic tank effluent was applied to each of the three soils at appropriate design rates via subsurface septic lines. The soils included had sand contents of 80, 41, and 7.6%. Indigenous concentrations of fecal coliforms in the effluent were more than sufficient to assure detectability. During the winter the levels of indigenous coliphages decreased, and on several occasions the septic effluent was spiked with cultured coliphages. The remainder of the year, indigenous levels were sufficient to allow adequate detection. Leachate samples were analyzed on a continuous basis, and at the end of the study the soils below the septic lines were dissected and sampled on a grid pattern. They were analyzed for both fecal coliforms and coliphages.On only a few occasions were fecal coliforms present in leachate collected 120 cm below the septic lines. Subsequent samples from the same locations did not indicate the presence of fecal coliforms so that the few samples that were collected shortly after application began may have been a result of contamination, or they may be indicative of greater mobility before organic residue built up in the soil. Soil samples taken 1 and 2 years after application began indicated limited mobility and survival of fecal coliforms in all three soils.Coliphages were present in the leachate only in very low concentrations immediately after spiking of the applied sewage with 103 times more organisms than were applied. Soil samples also confirmed the limited mobility of coliphages. Thus, 120 cm of any of the soils tested appeared to be sufficient to minimize the possibility of ground water pollution by fecal coliform or coliphages from septic effluent disposal.
Pollutant Movement to Shallow Ground Water Tables from Anaerobic Swine Waste Lagoons
Authors: Ciravolo T. G. , Martens D. C. , Hallock D. L. , Collins E. R. , Kornegay E. T. , Thomas H. R. 
Published: July 2010

AbstractThe effect of three anaerobic swine waste lagoons on ground water quality was investigated in the Atlantic Coastal Plain region. The lagoons studied were located on high‐water‐table soils with different textures. Ground water was sampled from wells, with unperforated casings, located at depths to 6 m and distances to 30 m from the lagoons. These samples were taken monthly from September 1974 through January 1975, and bimonthly thereafter through November 1975. Ground water also was sampled in November 1975 from shallow wells with perforated casings located at distances to 36.6 m from two of the three lagoons. Constituents determined to investigate ground water contamination were density of fecal coliforms and concentrations of Cl, Cu, Mn, NH4‐N, NO3‐N, PO4‐P, and Zn.Chloride, NH4‐N, and NO3‐N concentrations in ground water samples indicated that seepage entered ground water from each of the three lagoons. Rupture of lagoon seals leading to seepage was attributed to drying of exposed subsoil or embankment soil during recession of lagoon liquid levels and to gas release from microbial activity in soil beneath the seal. Overall, a low level of ground water contamination occurred around a lagoon that was in operation for over 8 years in Myatt very fine sandy loam with a clay subsoil, and a lagoon that was in operation 1 mo prior to this investigation in Dragston fine sandy loam with a sandy clay loam subsoil. Ground water contamination in excess of recommended drinking water standards for Cl and NO3‐N occurred around the third lagoon. This lagoon was in operation for >8 years in a disturbed area consisting of predominantly sandy surface and subsurface soil. Ground water contamination in the embankment area of this lagoon was attributed to seepage and beyond the embankment area to ground water contamination from lagoon overflow.
Prediction of Algal‐Available Phosphorus in Runoff Suspensions
Authors: Huettl P. J. , Wendt R. C. , Corey R. B. 
Published: July 2010

AbstractMethods for estimating the potential availability of sediment‐P forms are desirable for better assessment of the impact of runoff waters on surface water quality. The P sorbed by resin‐affixed hydroxy‐aluminum equilibrating with simulated sediment suspensions was evaluated for use as a routine means of estimating relative availability of P. A highly significant relationship (r = 0.98**, n = 5) was found between availability estimated by resin extraction and that determined by bioassay. For the soils tested, resin‐extractable P averaged 98% of that found to be available to algae by bioassay.
Degradation and Leaching of Acrylamide in Soil
Authors: Lande Sheldon S. , Bosch Stephen J. , Howard Philip H. 
Published: July 2010

AbstractSince some uses of acrylamide could cause ground water contamination, potential hazards were assessed by evaluating the degradation and leaching of 14C‐acrylamide (labelled at the carboxyl position) in four soils: silt loam, clay loam, loamy fine sand, and loam. The soil degradation study utilized the biometer flask method. Acrylamide half‐life (t1/2) was estimated by the time required for release of one‐half the evolved 14CO2. Half‐life was influenced by incubation temperature, acrylamide concentration, and the season at which the soil was collected. At ambient temperature (22°C), half‐lives ranged from 18 to 45 hours for 25 ppm acrylamide (on a soil basis). Decreasing temperature or increasing acrylamide concentration increased half‐life. Half‐life was two and one‐half times greater in soil gathered in spring than the same soil gathered in summer. When acrylamide was incubated in anaerobically maintained soil, it apparently metabolized more slowly. Leaching was evaluated by soil TLC. Rf values, which ranged from 0.64 to 0.88, place acrylamide into the “mobile class.”
Drainage Control to Diminish Nitrate Loss from Agricultural Fields
Authors: Gilliam J. W. , Skaggs R. W. , Weed S. B. 
Published: July 2010

AbstractIn an attempt to reduce NO3−‐N movement to drainage waters, flashboard riser‐type water level control structures were installed in tile mains or outlet ditches at two locations to raise the water table to increase denitrification during the winter. A large reduction in NO3−‐N movement through tile lines occurred (from 25–40 to 1–7 kg/ha) in moderately well‐drained soils because of reduction in effluent volume. In the moderately well‐drained soils, there was no indication of increased denitrification in the field. In poorly drained soils, drainage control had no influence upon soil profile oxidation‐reduction potentials but resulted in approximately.a 50% reduction in NO3− movement through drainage ditches. This reduction was due to increased water movement into and through deeper soil horizons (below 1 m). The NO3−‐N concentrations and low Eh values in all profiles below 1 m indicate that the NO3− which moved to this depth underwent denitrification.
Evaluation of Changes in the Nile Water Composition Resulting from The Asswan High Dam
Authors: Balba A. Monem 
Published: July 2010

AbstractThe composition of Nile River water has been examined to show the effect of the Asswan High Dam on the fertility and salinity of the water for irrigation.The Nile water contains about 110 × 106 metric tons/year of suspended materials as it crosses the Egyptian border. Before the Asswan High Dam was constructed, 24 × 106 metric tons/year of solids were deposited, mainly on the Egyptian flood plains. After the dam was finished, only 2.1 × 106 metric tons/year of solids were present in the Nile water to be deposited on the Egyptian soils; the remainder, 21.9 × 106 metric tons/year of solids, settled out in Lake Nasser.The loss of nutrients in the sediments which settled out in Lake Nasser, and the gain in soluble cations which resulted from construction of the Dam, were calculated from sediments and water analyses. The loss of 12,000 metric tons/year of sediment N is probably not significant for Egyptian agriculture. The loss of P, including a maximum of 6,000 metric tons/year of soluble P, will probably require a significant increase in the use of P fertilizers.The quality of the Nile water for irrigation, as determined by values for electrical conductivity, sodium adsorption ratio, adjusted sodium adsorption ratio, residual carbouate, and pHc, did not change significantly after construction of the dam.
Hydrology and Chemical Quality of Flow from Small Pastured Watersheds: II. Chemical Quality
Authors: Chichester F. W. , Van Keuren R. W. , Mc Guinness J. L. 
Published: July 2010

AbstractA beef cattle‐pasturing system involving four rotationally grazed summer pastures with winter‐feeding on one pasture was studied on sloping upland watersheds in Ohio to determine its effect on chemical quality of water. The concentrations of chemicals in runoff from the pastures, which were summer‐grazed only, increased relative to that of incoming precipitation but not enough to significantly impair water quality. No measurable sediment was lost from the pastures used only for summer grazing, allowing no chemical movement via that pathway. Much soil and plant‐cover disturbance on the pasture used for winter‐feeding, however, resulted in increased runoff, some surface erosion, and more chemical movement as compared with the pastures grazed only in summer. Considerably more chemicals moved in subsurface than in surface flow from the summer pastures while amounts of chemicals transported from the winter‐feeding pasture were equally as great in surface runoff and subsurface flow. Watershed surface management was a key factor in determining the flow route of water in excess of that used for evapotranspiration and, hence, the pathways and amounts of chemical transport from the pastures.