Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 21, 2007) Includes bibliographical references.

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Response of barley (<i>Hordeum vulgare</i> L.) and wheat (<i>Triticum aestivum</i> L.) to root-applied chlorsulfuron (2-chloro N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl) amino] carbonyl] benzenesulfonamide), a herbicide for use in small grains, was investigated. The results showed that, although wheat roots take up more chlorsulfuron than barley roots, barley was less tolerant to chlorsulfuron and chlorsulfuron was more mobile in barley. This study indicated that difference in uptake or translocation cannot explain the differential response of the two species to root-applied chlorsulfuron. In an interaction study, significant chlorsulfuron antagonism on ryegrass (<i>Lolium multiflorum</i> Lam.) control by diclofop {(±)[-2-[4-(2,4-dichlorophenoxy) phenoxy) propanoic acid} was observed. Greenhouse experiments showed that the tolerance of corn (<i>Zea mays</i> L.) to chlorsulfuron and metsulfuron (2-[[[[(4-methoxy-6-methyl-l,3,5-triazin- -2-yl) amino] carbonyl] amino] sulfonyl] benzoic acid) was greatly increased by seed dressing with the herbicide safener NA (1,8-naphthalic anhydride). The soil behavior of chlorsulfuron was studied in the field, greenhouse and laboratory. In the field, corn adequately tolerated soil residues present 10 months following postemergence application of chlorsulfuron at 10 to 120 g/ha. However, at the same site and rates, residues from chlorsulfuron injured corn when sampled 2 months after application. In laboratory studies chlorsulfuron was moderately adsorbed by organic matter but showed low affinity to clay. R_f values calculated from soil thin-layer chromatography closely correlated with the mobility of chlorsulfuron leached with 16.8 cm of water over a 14-day period in hand-packed soil columns. In the soil thin-layer chromatography, chlorsulfuron mobility was positively and negatively correlated with pH and organic matter, respectively. The results indicated that chlorsulfuron could be mobile in low organic matter and non-acidic soils. The relationship of chlorsulfuron phytotoxicity to soil physical and chemical properties was also evaluated. Organic matter was inversely related to chlorsulfuron phytotoxicity while no such relationship to clay content was observed. The adsorption of chlorsulfuron decreased with increasing soil pH whereas desorption was greater at alkaline pH. / Ph. D.

Soil column studies were performed on a chromium contaminated soil from the United Chrome Products Superfund Site currently undergoing a pump-and-treat cleanup process. The goal of the research was to provide insight into the feasibility of chemically changing the injection fluid of the pump-and-treat system to enhance hexavalent chromium (Cr(VI)) mobility. The parameters tested were pH, ionic strength, and competitive anion type and concentration. Ionic strength effects were investigated by adjusting the NaCl concentration of the extracting solution and by observing the influence of varying anion concentrations on desorption (bicarbonate, sulfate, and phosphate). The results indicated that high ionic strength solutions slow the rate of Cr(VI) desorption. This possibly indicates most of the Cr(VI) was in pore water solution and was adsorbing, slowing the removal process. Cr(VI) desorption was fastest for distilled water solution followed by competitive anion/distilled water solutions. The high ionic strength extracting solutions, 0.05 M and 0.10 M NaCl, had the slowest Cr(VI) desorption rates. Effluent pHs dropped as the ionic strength was increased (increasing NaCl concentrations) which was attributed to a Na-H exchange. Increased concentrations of bicarbonate, sulfate, and phosphate resulted in only small pH differences in the effluent of less than 0.5 pH units. The effect of pH was investigated by varying the pH of the 0.01 M NaCl solution with strong acid and base and by varying the pH of phosphate competitive anion solutions. The effects of changing 0.01 M NaCl solution pH were inconclusive. Differences between Cr(VI) desorption rates for the soil columns with adjusted influent pHs were small. Cr(VI) desorption curves and column effluent pH values for phosphate solutions of varying influent pH values were nearly identical, indicating that soil buffering and effluent pH are more important factors than influent pH in achieving Cr(VI) desorption. Nitrate, bicarbonate, sulfate, and phosphate were investigated to determine the effect of various competitive anions on Cr(VI) desorption. The effectiveness of each anion at extracting Cr(VI) from soil appeared to follow the order of adsorption affinity to the soil. / Graduation date: 1992

Graduation date: 1993

Made available in DSpace on 2014-06-11T19:30:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-11-30Bitstream added on 2014-06-13T19:00:29Z : No. of bitstreams: 1 leles_ep_dr_botfca.pdf: 1605420 bytes, checksum: fd161316ca168c50775ac745c3ae8681 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A reduzida eficiência de aproveitamento dos fertilizantes fosfatados é influenciada pela solubilidade de suas fontes. Uma das alternativas para melhorar a disponibilidade de P nos solos e aumentar o aproveitamento dos fertilizantes é a aplicação de silicatos. Para verificar a influência dos corretivos de acidez e das fontes de fósforo nos atributos químicos do solo ao longo do tempo foi realizado o Experimento 1, utilizando um LATOSSOLO VERMELHO distrófico. O delineamento experimental foi de blocos casualizados, com quatro repetições, em esquema fatorial 2 x 5, com dois corretivos de acidez (calcário dolomítico e escória de aciaria) e cinco tratamentos, sendo uma testemunha (sem NPK), uma testemunha relativa (sem fósforo) e os demais tratamentos constituídos de diferentes fontes de fósforo (superfosfato triplo – ST; termofosfato – TM; fosfato natural reativo – FNR). Os corretivos de acidez tiveram mesmo efeito na elevação de pH do solo. A escória de aciaria resultou em maior teor de P apenas 30 dias após incubação. Independente do corretivo, 150 dias após a incubação, o teor de P no solo seguiu a ordem ST > TM = FNR > sem NPK = sem P. Para verificar os atributos químicos do solo, a nutrição e a produção de amendoim e do capim marandu em solos sob a influência dos corretivos de acidez e das fontes de fósforo, foram... / The low efficiency of utilization of phosphates fertilizers is influenced by the solubility of its sources. An alternative to improve the availability of P in soils and increase the use of fertilizers is the use of silicates. To evaluate the influence of the acidity correctives and sources of phosphorus in soil chemical properties over time, the Experiment 1 was performed using a Dystrophic Red Latosol. The experimental design was randomized blocks with four replications in a factorial scheme 2x5, with two acidity correctives (dolomitic limestone and steel slag) and five treatments, as a control (without NPK), a relative control (without phosphorus) and the other treatments consisting of different phosphorus sources (triple superphosphate - TS, thermo phosphate - TM and reactive natural phosphate - FNR). The acidity correctives had the same effect in the rise of soil pH, and the steel slag resulted in higher value than limestone in P resin in soil only 30 days after incubation. Independent of the acidity correctives, 150 days after incubation, the value of soil P followed the order ST > TM = FNR > sem NPK = sem P. To evaluate the chemical soil properties, nutrition and production of peanuts and grass in soils under the influence of the acidity correctives and phosphorus sources, were conducted the Experiments 2 and 3 in FCA – UNESP, Botucatu campus. In peanuts, the application of steel slag resulted in highest plants with biggest leaves+stalk dry matter production than limestone, however the grain dry matter per vase was biggest when the limestone was applied, following the order TM = FNR > ST > sem P in this corrective. In marandu grass, comparing the correctives, with steel slag the total production of dry matter was upper in the soil control and the limestone in... (Complete abstract click electronic access below)

The objectives of the study were to investigate the sorption and degradation of a glucuronide conjugated natural hormone, 17β-estradio1-3-glucuronide (E2-3G), and its estrogenic metabolites in soil-water systems. Radiolabeled E2-3G was first synthesized in the laboratory. Soil-water batch experiments were then conducted using natural and sterilized topsoil (0-6 cm) and subsoil (18-24 cm) with the radiolabeled E2-3G to investigate the effects of soil organic matter content and microbial activity. The aqueous dissipation of 14C in the batch experiments followed a biphasic pattern with an initial rapid dissipation phase followed by a second slower phase. Significant differences in total aqueous 14C dissipation were observed for the different initial concentrations for both soils, with greater persistence of intact E2-3G at higher initial concentrations. / National Science Foundation [Grant No. 0730492]