bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tritiated Water Movement in Semiconfined Growth Systems
Authors: Klobe W. D. 
Published: July 2010

AbstractSince its beta radiation will not penetrate the skin, the major hazard of tritium (3H) to man is via the food pathways. This investigation was designed to provide preliminary information on 3H behavior in the food pathways, which include soils and plants.Each of six semi‐confined growth systems contained four corn (Zea mays L.) plants grown on 0.1 m3 of a fertilized peat‐sandperlite mixture. The bottom of each container and the surface of the growth medium was covered with plastic to prevent excessive loss of 3H due to evaporation or mass flow.The growth medium in each system received a single surface application of 3 mCi of tritiated water (HTO), and was kept near field capacity by watering every 2 or 3 days. Pairs of systems were labeled at 7, 10, or 13 weeks maturation of the corn, and the rate of 3H removal at different stages of plant growth was determined.Residence time of 3H in the growth medium was short. At maximum rates of withdrawal (transpiration), over 90% of the added 3H was removed within 1 week. The maximum amount of readily extractable 3H found in the plants was about 3% of the original application. This occurred 3 days after labeling and decreased to 0.1 to 0.3% in 2 weeks.
Recovery of Mercury in Solution
Authors: Maag G. W. , Hecker R. J. 
Published: July 2010

AbstractMercury in the metallic or ionic form is a poisonous pollutant when added to the sewage system. Analytical laboratories frequently use solutions which contain mercury salts and proper disposal of the waste solutions is a problem. A recovery method is described in which aluminum releases its higher energy valence electrons to the mercury ions in solution producing aluminum ions and metallic mercury. The metallic mercury is recovered and the waste solution containing the aluminum ions can be poured down the drain.
Influence of Selected Pesticides on Leaf Elemental Content and Yield of Garden Beans (Phaseolus vulgaris L.)
Authors: McClurg C. A. , Bergman E. L. 
Published: July 2010

AbstractFive experiments were conducted to determine the effects of selected herbicides, systemic nematocide‐insecticides, and a fungicide on foliar elemental content, stand, and yield of garden beans (Phaseolus vulgaris L.). None of the elements analyzed in the leaves nor stand, plant weight, or pod yields were significantly altered by DMPP or disulfoton systemic nematocide‐insecticide treatments. Foliar calcium levels were significantly reduced by several herbicide treatments. These treatments also caused greater plant injury and decreased stand and yields. Although benomyl fungicide at a soil concentration of 20 ppm significantly increased foliar calcium content, no general trends in elemental content could be determined. A greenhouse experiment testing effects of soil applied magnesium and EPTC herbicide indicated plant height was significantly reduced by increasing herbicide concentration. Magnesium application significantly increased foliar magnesium content and mean plant weight.
Using Race‐Specific Resistance to Manage the Evolution of Plant Pathogens
Authors: Knott D. R. 
Published: July 2010

AbstractThe life cycle of a pathogen and the epidemiology of the disease it causes determine the use that can be made of host genes for race‐specific resistance. Many pathogens, such as the potato late blight fungus, complete their life cycle in a limited area and the pathogen's evolution is determined by the host cultivars grown in the area. Other pathogens, such as the wheat stem rust fungus, survive part of the year in only a small area but then spread widely from this primary center of infection. The stem rust fungus rarely overwinters north of central Texas, but during spring and summer it spreads north 2,000 miles along the “Puccinia Path”. It normally does not survive the hot summer in the overwintering area. Thus, in the fall spores must be blown south to infect the young winter wheat crop. With an epidemiological pattern of this type, the evolution of pathogenicity in the fungus is determined by the host genes for resistance that are used in particular areas. The wheat crop is a patchwork of different resistance genotypes that act as a selection sieve through which only certain rust genotypes can pass. Man, by controlling the nature of the patchwork, can guide the evolution of the pathogen to achieve long‐lasting control of the disease.
Philosophy on the Biological Control of Insect Pests
Authors: Dicke F. F. 
Published: July 2010

AbstractBiological control may be defined as the balance between a species and biological stress factors that limit its potential population. Four major divisions are usually recognized in biological control research programs: (i) parasites and predators; (ii) insect pathology; (iii) radiation and genetics; (iv) host‐plant resistance.Introducing parasites and predators to combat introduced insect pests was vigorously pursued during the early 20th century. Again in recent years this facet of biological control research has received increased emphasis. Successful establishment of many introduced parasitic species has been recorded. Components of biological control agents usually lag in effect when host populations suddenly increase. Each species has its own realm of environmental requirements for optimum survival.Pathogenic viruses, bacteria, fungi, protozoa, and nematodes may reduce insect outbreaks rapidly under favorable temperature and moisture conditions. Examples include: (i) polyhedral viruses present in many species of Lepidoptera; (ii) milky disease bacteria in the Japanese beetle, and Bacillus thuringiensis in the European corn borer; (iii) fungi of the genera Empusa or Entomophthora, Beauveria, and Metarrhizium in many orders and a wide range of species; (iv) protozoa of the genera Nosema and Perezia in a wide range of hosts. Artificial dissemination has been successful for milky disease against the Japanese beetle and B. thuringiensis against the European corn borer. Male sterility induced genetically or by radiation is a promising approach to insect population control.Cooperative research programs have yielded significant varietal resistance to several insect species in economically important field crops such as wheat, maize, sorghum, and alfalfa.
Morphological and Chemical Changes that Evolve in the Development of Host Plant Resistance to Insects
Authors: Maxwell Fowden G. 
Published: July 2010

AbstractThe hypothesis that insects are evolving from a polyphagous to a monophagous state is presented. Chemical and physical factors involved in host selection by an insect are discussed. Certain morphological and chemical factors in plants have evolved as protective mechanisms against specific insects which have allowed survival. Man has genetically manipulated certain of these chemical and morphological factors to impart resistance to specific pests. In some cases, the factor or factors responsible for resistance to one pest may in themselves, or else through unknown linked factors, create greater susceptibility to another pest. Examples are given.
Toward Environmental Sanity
Authors: Ruckelshaus William D. 
Published: July 2010

AbstractGrowing national demand for environmental controls led to establishment of the Environmental Protection Agency which is charged with planning and executing an integrated, coordinated attack on environmental problems of air and water pollution, drinking water quality, solid wastes management, pesticides, radiation, and noise. Other Federal agencies also play a part in environmental control. A strong EPA regional organization has been established. Progress is being made toward pollution control in a number of areas but much, much more remains to be done. One emphasis of EPA program is on research and demonstration to combat present problems and to help anticipate future problems. Pollution control standards and laws must be enforced energetically or little will be gained. Continued public support of national, state, and local environmental control programs is basic to success.
Insecticide Depth in Soil—Effect on Soybean Uptake in the Greenhouse
Authors: Beall M. L. , Nash R. G. 
Published: July 2010

AbstractThe influence of DDT, dieldrin, and endrin placement depth in soil on their plant uptake and translocation was investigated. In a greenhouse study, soybeans were grown for 75 days in soil columns containing a 1‐cm layer of 20 ppm 14C‐insecticide‐treated soil placed at either 1–2, 16–17, or 31–32 cm deep (depths A, B, and C, respectively) within the column. Radioactivity in root sections showed that all three insecticides were absorbed and translocated both basipetally and acropetally. Maximum mean residues in roots (DDT, 14.9; dieldrin, 29.1; endrin, 29.5 ppm air‐dry basis) always resulted from placement at depth A.Maximum DDT (<0.01 ppm), dieldrin (0.68 ppm), and endrin (1.20 ppm) residues in total aerial organs resulted from depth A also. Residues decreased strikingly as placement depth increased. The B depth resulted in mean aerial residues amounting to 6.8% (dieldrin) or 15.0% (endrin) of those resulting from A, while C depth resulted in mean aerial residues of only 0.6% (dieldrin) or 6.7% (endrin) of those from depth A. Only trace amounts of DDT residues resulted from depths B and C.Since uptake was affected by insecticide placement depth, prediction of crop residues based on soil residues must include a consideration of residue location in soil. Results suggest that deep plowing of insecticide‐containing soil could be used to reduce residues in crop plants.
Arsenic Phytotoxicity on a Plainfield Sand as Affected by Ferric Sulfate or Aluminum Sulfate
Authors: Steevens D. R. , Walsh L. M. , Keeney D. R. 
Published: July 2010

AbstractRepeated use of arsenic (As) salts in orchards, cotton, and tobacco fields occasionally has caused phytotoxicity. A study was initiated to evaluate the effect of periodic applications of sodium arsenite (NaAsO2) which has been used extensively as a defoliant to kill potato vines in Wisconsin commercial potato fields. Sodium arsenite was applied in 1967 to a Plainfield sand at rates varying from 45 to 720 kg As/ha. In 1970, these field plots were subdivided and treated with ferric sulfate [Fe2(SO4)3] and aluminum sulfate [Al2(SO4)3] to attenuate As toxicity, planted to peas (Pisum sativum L.) and potatoes (Solanum tuberosum L.), and yields compared with those obtained in earlier investigations. Arsenic toxicity persisted over a period of four cropping seasons. Pea yields on As‐treated soil tended to be higher with an application of Fe2(SO4)3 and lower with an application of Al2(SO4)3, although yields generally were not significantly changed by either material. Potato yields were not affected by application of Fe2(SO4)3, therefore, neither Fe2(SO4)3 or Al2(SO4)3 were effective at the rate used in reducing toxicity. Potato tuber peelings contained up to 53.7 ppm of As, but regardless of treatment, the tuber flesh did not exceed 1 ppm. Ferric sulfate or Al2(SO4)3 did not have a consistent effect on the concentration of As in potato peelings or tuber flesh. The As content of As‐treated soil increased in the subsoil but decreased in the plow layer during four cropping seasons. The increase in subsoil As was found to a depth of 38 cm and 68 cm for treatments of 90 and 180 kg As/ha and 720 kg As/ha, respectively. Even considering the downward movement, all of the As applied in 1967 as NaAsO2 was not accounted for in the soil profile (0–83 cm).
Microbiological Quality of Subsurface Drainage Water from Irrigated Agricultural Land
Authors: Smith J. H. , Douglas C. L. , Bondurant J. A. 
Published: July 2010

AbstractIrrigation and subsurface drainage waters sampled from an 82,150‐hectare (203,000‐acre) irrigation district in southern Idaho were evaluated for bacteriological quality. The soils in the district are wind deposited over fractured basalt, calcareous, and have a pH near 7.8. Drainage, where needed, is provided by horizontally mined tunnels or by tile drains connecting shallow relief wells that flow the year around. For the 12 month ending September 30, 1969, a 2‐meter (6.5‐foot) depth of water for the entire irrigation tract was diverted, and 50% of the water passed through the soil becoming subsurface drainage. The irrigation water and seven subsurface drains were sampled at 2‐week intervals during the summer of 1969. Coliform, fecal streptococci, starch hydrolyzers, and bacteria able to grow at temperatures from 0 to 55C were counted. The diverted irrigation water contained from 140 to 3,300 coliform per 100 ml, but 86% of the subsurface drainage samples contained 5 or fewer coliforms per 100 ml. Numbers of other microorganisms were also low in the drainage waters. The outflow samples were oxygen saturated and the temperatures were 13.0 ± 1.1C for all samples. Percolation through the soil improved the water quality almost to domestic water standards.
Photooxidative Degradation of Ligninsulfonate to Substrates Enhancing Microbial Growth
Authors: Rockhill R. C. , Park J. E. , Klein D. A. 
Published: July 2010

AbstractPhotolysis was evaluated as a procedure by which a recalcitrant polymer could be modified to improve biological availability. Ligninsulfonate was used as a model substrate, and Aspergillus growth responses measured by fungal dry weight in relation to substrate carbon before and after growth. Ligninsulfonate solutions with initial pH values of 3, 7, and 12 were irradiated, and maximum growth response found to occur where decoloration was achieved. The photolysis time required for decoloration increased with pH. Approximately 50% of the total carbon was utilized in all cases at the point of maximum microbial growth response. Photolysis at all exposure times altered the substrate in such a way as to increase microbial response and, therefore, appears to be an effective method for treating ligninsulfonate to increase microbial degradation.
Water Soluble Organic Substances Leachable from Feedlot Manure
Authors: Mosier A. R. , Haider K. , Clark F. E. 
Published: July 2010

AbstractWater extracts of feedlot manure and soil and of grassland soil were compared with water from shallow wells near to and remote from feedlots and with water from a local river. Thin‐layer and column chromatography failed to reveal water‐soluble organics unique to feedlot ground waters. Free phenolics could readily be leached from feedlot manure and from the upper few centimeters of feedlot soil, but only trace amounts of low‐molecular‐weight organics were encountered in the ground water samples examined. The major organic constituents in all the well waters appeared to be polymerized materials. Mildly reductive degradation of the organic polymers in leachates prepared from feedlot manure, feedlot soil, and grassland soil yielded identifiable phenolics; the same procedure failed to reveal phenolics in ground waters. It was concluded that there is no uniform or continuing movement of organic material from feedlots through the soil profile to the ground water under the feedlot sites involved.
Land Disposal of Liquid Sewage Sludge: I. The Effect on Yield, in vivo Digestibility, and Chemical Composition of Coastal Bermudagrass (Cynodon dactylon L. Pers)
Authors: King Larry D. , Morris H. D. 
Published: July 2010

AbstractThe disposal of liquid sewage sludge on established Coastal bermudagrass sod was studied over a 2‐year period. Rates of sludge application up to 20 cm/year were compared with a conventional fertilizer treatment.In 1969 there were no significant differences among the three highest sludge rates and all sludge rates were superior to chemical fertilizer (224‐37‐97 kg/ha NPK) in forage production. In 1970 no significant differences were found among the three top rates of sludge and a higher rate of chemical fertilizer (358‐112‐224 kg/ha NPK) that was used. Sludge applications had little effect on in vivo digestibility of the forage. The K level of the forage was initially increased by sludge applications but steadily declined during the last half of the 1969 season and the entire 1970 season. Sludge applications increased the N and Na level of the forage but had little or no effect on P, Ca, Mg, Mn, B, Cu, Mo, and Ni. Zinc content of the forage increased with increasing sludge rate and number of application through the second clipping in 1970. Although Zn levels of 340 ppm were found no reduction in yield resulted. There was no significant survival of coliform bacteria on the forage at harvest. Results of the investigation indicate that Coastal bermudagrass is a well‐adapted crop for sludge disposal areas.
Increased Denitrification in Soils by Additions of Sulfur as an Energy Source
Authors: Mann L. D. , Focht D. D. , Joseph H. A. , Stolzy L. H. 
Published: July 2010

AbstractDenitrification rates were studied in four large soil columns using Hanford sandy loam and Moreno silty clay loam soils. One column of each soil was amended with sulfur to serve as an energy source for the bacterium Thiobacillus denitrificans. Limestone was also added as a pH buffer. The other column of each soil was left untreated to serve as a control. A solution of Ca(NO3)2 containing 425 ppm NO3‐N was perfused continuously through the columns. The columns were monitored periodically at depths of 10, 30, 50, 70, and 90 cm for nitrate, nitrite, redox potential (Eh) and microbial numbers. Highly anaerobic conditions developed in all columns as was evidenced by low Eh values at each depth. All of the nitrate was reduced in each column, and nitrates penetrated to lower depths in the untreated columns. Nitrite concentrations were found to be negligible. Denitrification rate constants were established as 0.174, 0.520, 0.186, and 1.426 days−1, for the Hanford‐untreated, Hanford‐treated, Morneo‐untreated, and Moreno‐treated columns, respectively. Sulfur additions to field soils which are low in microbial energy sources could be an effective method of reducing the nitrate level in waters percolating through the profile.
Sediment‐Water Interactions
Authors: Oschwald W. R. 
Published: July 2010

AbstractSediment originating from soil erosion has physical, chemical, and biological effects on water resource use. Sediment particles pollute water to the extent that their presence reduces water quality for a particular use.The physical presence of sediment produces turbidity. Turbid water has impaired water quality for most uses. Reduction in light penetration due to suspended sediment may alter oxygen relationships in surface water. Production of fish and other aquatic life is reduced by excess turbidity. Taste and odor, temperature, and abrasiveness of water may be altered by the physical presence of sediment.Sediment in water provides a surface for the sorption and desorption of potential pollutants. The sediment particles may scavenge or remove substances such as nutrients, pesticides, heavy metals, and radioactive isotopes from water. The sorbed substances may be fixed so that they no longer are available as pollutants. They may be contacted by aquatic organisms and concentrated, in the aquatic food chain. Deposits of sediments with their sorbed constituents may be buried by later deposition. The buried deposits may be re‐exposed or transported to new locations. The effects of sorption and desorption may be different in short term and long term periods.Sediment influences eutrophication through deposition of sediments and through nutrients released from the sediments. The deposition effects are more obvious and may have a greater effect on eutrophication than the nutrients in the sediments.
Bionomics and Integrated Control of Plant Parasitic Nematodes
Authors: Good J. M. 
Published: July 2010

AbstractPlant parasitic nematodes occur naturally in undisturbed soils. Establishment of an agroecosystem promotes the rapid increase of endemic pathogenic species and allows introduction of nonendemic species that quickly establish dominance. Nematodes now cause about 10% loss of yields of crops in the United States. About 20 highly effective nematicides are available to control nematodes and associated plant diseases in a number of crops. Nematode populations can be regulated by a number of soil management practices, including clean transplant, seed production, and crop rotations. Biological control can be achieved by addition of various types of organic matter to soil, some of which are not presently utilized, especially biodegradable solid waste. Over 152 nematode‐resistant crop varieties representing 17 major crops are available with resistance from one to three species of the 10 most destructive nematode types. Physical methods of control, including quarantine, sanitation, and crop destruction, are not vigorously applied. All methods available for nematode control have not been utilized in integrated control systems. Further research and development will allow use of integrated management systems, using several basically different approaches to nematode control, with nematicides used to supplement other control methods.
Mild Thermal Degradation of Pesticides
Authors: Stojanovic B. J. , Hutto Fay , Kennedy M. V. , Shuman F. L. 
Published: July 2010

AbstractPartial degradation of 12 selected analytical grade pesticides was produced by heating the chemicals at temperatures between 100 and 400C. Each pesticide was modified physically and chemically at a temperature at least 300–450C below its complete combustion temperature. At these relatively low temperatures eight of the original nine solids (zineb, picloram, dieldrin, atrazine, bromacil, carbaryl, DNBP, and 2,4‐D) remained solid, while dicamba was converted to a liquid. The three liquids (DBCP, vernolate, and malathion) were all converted to solids. Eight of the original 12 compounds also yielded gray to brown to black residues upon heating. Infrared spectroscopic analyses indicated that the extent of degradation of the heated pesticides ranged from formation of a single degradation product to production of a mixture of compounds. Most pesticides, however, were degraded through loss of one or two substituents of the molecule by processes such as dehalogenation and decarboxylation.
Leachate Quality from Acidic Mine Spoil Fertilized with Liquid Digested Sewage Sludge
Authors: Peterson J. R. , Gschwind John 
Published: July 2010

AbstractThe leachate quality from an acidic mine spoil was upgraded by the addition of liquid digested sludge. Mixing liquid sludge with acidic spoil material (pH 2.5) at a w/w ratio of 1:37 (61 metric tons/ha, dry basis), reduced leachate constituents as follows: total acidity, 17%; Al, 99%; Fe, 80%; and soluble salts, 41% for this 110‐day study. During this period leachate showed increases in: NH3‐N, 1689%; SO4, 49%; Zn, 1941%; and Mg, 827%. The pH of this leachate increased immediately to 4.6 (check column remained near 2.5) and continued with a gradual neutralization. The mixing of sludge with this spoil material at a w/w ratio of 1:18 (122 metric tons/ha, dry basis) was the second most efficient for water amelioration. This leachate had an immediate pH increase of 4.5 and an eventual increase to pH 8, a 99% reduction in Al, an increase in NH3‐N by 3131%, and total P by 1069% over the check column leachate. A third ratio of sludge to acidic soil of 1:37 mixed in the top quarter of the column showed the least leachate amelioration, but after 30 days of leaching, nitrification began in this column, indicating aerobiosis and a pH of > 5.4 in a part of the soil column. The columns were leached 1 hour/day with 1.36 cm of aerated deionized water so that unsaturated flow occurred during a part of each day.