Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 178-190).

Title from PDF of title page (University of Missouri--Columbia, viewed on February 24, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Dale Blevins. Vita. Includes bibliographical references.

The relationship between plants and rhizosphere bacteria collected from a 45 year old permanent pasture was investigated. Several methods of strain identification within Rhizobium trifolii were evaluated. Separation of bacterial isolates based on differences in intrinsic antibiotic resistance was not appropriate because strains developed hybrid resistance patterns when grown in a common broth. Serological analyses of bacterial antigens using polyclonal antiserum yielded two reliable methods for identifying R. trifolii isolates. Agglutination and immunofluorescence procedures were not useful in distinguishing these strains but immunodiffusion and the enzyme-linked immunosorbent assay (ELISA) were highly suitable. Adaptation of the ELISA allowed isolates to be identified directly from individual root nodules without first subculturing the bacteria. A strain of Bacillus polymyxa isolated from the same pasture was shown to stimulate growth of crested wheatgrass (Agropyron cristatum L.) and white clover (Trifolium repens L.). The primary manifestation of the effect was increased root weight (P < 0.05), but shoot responses were also observed. Perennial ryegrass (Lolium perenne L.) generally reacted negatively to inoculation with this bacterium. Further stimulation of growth was noted when ramets of the white clover genotype homologous to (sharing a common origin) B. polymyxa were inoculated in pure stands (P < 0.05). Clones of the homologous perennial ryegrass genotype also showed a yield increase from slightly below control levels to slightly above them when tested in a similar manner. Detailed analysis of the crested wheatgrass response to inoculation revealed that bacterial production of indole acetic acid was the most likely cause of the growth stimulation. Other bacterial characteristics such as the ability to fix atmospheric nitrogen or to solubilize organic phosphorus were concluded to be unrelated to the growth response. Co-adaptive compatibility between genotypes of L. perenne and T. repens was not apparent when the effect of R. trifolii was ignored. However, when clones of pasture plants that had been neighbours in the field were inoculated with R. trifolii isolated from root nodules of the "parental" clover genotype, biotic specialization between the pasture plants became evident. The magnitude of the effect, which was characterized by superior white clover yields (P < 0.05), could be largely accounted for by the presence of the adapted L. perenne/R. trifolii combinations, regardless of the white clover genotype. Since T. repens was the dominant component in the species mixture, these trends were also apparent when total forage biomass was analyzed (P < 0.05). However, ecological combining ability was found to be lowest in these associations (P < 0.05). Similar experimentation with isolates of B. polymyxa (or B. polymyxa-like organisms) was performed. Again the grass/bacteria combination was shown to be influential in the growth response as the presence of homologous L. perenne/B. polymyxa combinations resulted in superior white clover and perennial ryegrass performance (P < 0.05). When T. repens was inoculated with a mixture of R. trifolii strains, unrelated isolates formed more root nodules than did homologous ones (P < 0.05). The presence of perennial ryegrass did not mitigate this effect. However, when homologous R. trifolii was administered as a single strain inoculum, yield advantages in white clover were observed (P < 0.05). If B. pol ymyxa was present, homologous strains of R. trifolii tended to form most of the root nodules regardless of the T. repens or L. perenne genotypes. The significance of the yield advantages observed in various two and three-way plant/microbe genotype combinations is discussed with respect to above ground plant performance. / Land and Food Systems, Faculty of / Graduate

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Biomass, cover, density, height and concentrations of N, P, C, Fe, Mn, Cu and Zn were evaluated in Sporobolus cryptandrus and Eragrostis lehmanniana at flowering and at seed ripening stage to determine whether these attributes are affected by the type of litter used or by litter treatment. Annual rye, California poppy and rye-poppy mixture were the sources of litter while litter treatments included removing organic residue, leaving organic residue standing or roto-tilling organic residue into the surface soil. The effect of litter type and litter treatment on the soil was evaluated. A parallel greenhouse experiment was carried out. Results indicate that California poppy contained a higher level of all nutrients studied compared to annual rye and contained about twice the concentrations of N, Mn, Zn and Fe. For both annuals and perennials, the nutrient content generally decreased between flowering and seed ripening with annuals indicating more decline than perennial grasses. The greatest decline was observed for N in California poppy. Field observation confirmed that the non-lignified California poppy shoots broke down faster than culms of annual rye. Biomass production in Sporobolus and Eragrostis was unaffected by litter type. However, for both species the highest biomass was obtained in the tilled treatment. Litter tilling produced more vigorous and healthier plants compared to other treatments. Except for P, nutrient concentrations were largely unaffected by litter type. The highest P concentrations were consistently obtained from perennial plants grown in annual rye plots. Fe and Cu concentrations were consistently higher in the tilled treatment. C and P appeared unaffected by litter treatment. N, Mn and Zn concentrations were more variable and more difficult to categorize. In soil samples, all nutrient concentrations were higher at the end of the study than at the beginning. Litter source appeared to have minimum effect on nutrient concentration while tilled treatment was superior to standing which was superior to the removed treatment.

Made available in DSpace on 2014-06-11T19:31:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-07-20Bitstream added on 2014-06-13T20:01:28Z : No. of bitstreams: 1 ferreira_mm_dr_jabo.pdf: 259449 bytes, checksum: 6bdfca425dd270d01aa7935258ef0f96 (MD5) / Tem-se procurado incentivar o estudo de viabilidade do uso de sistemas integrados de produção de energia e alimentos para, da melhor forma possível, se utilizar os recursos específicos de cada agros sistema e se criar, sempre que possível, circuitos de realimentação entre diversas atividades. de modo a transformar resíduos em riquezas. Nesse contexto, desenvolveram-se estudos durante os anos de 2007 a 2011, em área experimental da Faculdade de Ciências Agrárias e Veterinárias da Universidade Estadual Paulista, em Jaboticabal-SP, Brasil.Utilizou-se de um latossol roxo com 12% de declividade e exposição Norte. Considerou-se como tratamentos a utilização de efluente de biodigestor incorporado ao solo em três doses diferentes, e como testemunha a adubação mineral convencional e sem adubação. Os principais aspectos analisados foram: densidade aparente do solo; Velocidade de infiltração da água no solo; desenvolvimento da área foliar, acumulação de matéria seca nas diferentes partes e produção de grãos da planta de milho. Da análise dos resultados e nas condições que se desenvolveu o estudo, concluiu-se que o efluente de biodigestor aplicado em anos consecutivos promove um melhor condicionamento do solo e um melhor desenvolvimento das plantas / The use of integrate systems has been stimulated to produce energy and food, so that specific resources of each agrosystem can be used in the best way, as well to create always as possible circuits of feedback between various activities so as to transform residues in wealth. so, a study using corn crop was carried out from 2007 to 2011, in the FCAV/UNESP Experimental Farm, in Jaboticabal City, State of São Paulo, Brazil. Red soil with 12% slope and north exposition was used. The treatments consisted of three levels of biodigestor biofertilizant incorporated into soil, conventional mineral fertilization (control 1) and without fertilization (control 2). To reach the objectives the following parameters were evaluated: soil apparent density, water infiltration speed into the soil, development of corn foliar area, dry matter accumulation and yield. Based on the results and the experimental conditions it was concluded that the biodigestor biofertilizant applied during successive years into the soil promoted better soil conditioning, as well as plant development

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Typewritten Includes bibliographical references