Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Thesis (Ph. D.)-- State University of New York at Binghamton, Department of Geological Sciences and Environmental Studies, 2009.

Thesis (doctoral)--Universität Kiel, 1995. / Includes bibliographical references (p. 160-177).

Thesis (M.S.)--Indiana University, 2008. / Title from screen (viewed on June 3, 2009). Department of Earth Science, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Lin Li, Pierre Jacinthe, Gabriel M. Filippelli. Includes vita. Includes bibliographical references (leaves 78-81).

Thesis (Ph. D.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2006. / Michael Bergin, Committee Member ; E. Michael Perdue, Committee Chair ; Ching-Hua Huang, Committee Member ; Ellery Ingall, Committee Member ; Martial Taillefert, Committee Member. Vita. Includes bibliographical references.

Techn. University, Diss., 2004--Darmstadt.

Orientador: Antonio Ismael Inácio Cardoso / Banca: Camila Paula Rossetto Pescatori Jacon / Banca: Adalton Mazetti Fernandes / Banca: Pamela Gomes Nakada Freitas / Banca: Felipe Oliveira Magro / Resumo: Um dos fatores essenciais para a obtenção de altas produtividades é o correto manejo da adubação, aperfeiçoando os métodos de utilização dos fertilizantes orgânicos e minerais. Entretanto, ainda que existam estudos relacionados com a nutrição mineral e recomendações de adubação para o cultivo comercial de alface e de outras hortaliças em geral, dificilmente se encontram trabalhos que abordem os efeitos dos nutrientes na produção e qualidade de sementes. Objetivou-se, com o presente trabalho, avaliar doses de enxofre em cobertura, com e sem aplica de com composto orgânico no plantio, na produção, extração de macronutrientes e qualidade fisiológica de sementes de alface. Foram avaliados dez tratamentos, em esquema fatorial 5x2 (cinco doses de enxofre em cobertura x com e sem aplicação de composto orgânico no plantio). Utilizou-se o delineamento experimental de blocos casualizados, com quatro repetições, contendo cinco plantas por parcela, sendo três úteis. As doses de enxofre aplicadas em cobertura foram 50, 100, 150 e 200 kg ha-1 de S, além da testemunha (dose 0). Para os tratamentos com composto orgânico utilizou-se a dose de 70 t ha-1 (base úmida). Foram avaliadas as seguintes características: índice de clorofila nas folhas, produção de sementes (em massa e em número por planta), qualidade de sementes (massa de mil sementes, primeira contagem no teste padrão de germinação, germinação, índice de velocidade de germinação, índice de velocidade de emergência e taxa de plântulas ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: One of the essential factors to obtain high productivity is the correct management of fertilization, improving methods of utilization of organic and mineral fertilization. However, although there are studies related to mineral nutrition and fertilization recommendations for the commercial cultivation of lettuce and other vegetables in general, there are hardly any studies that address the effects of nutrients on seed production and quality. The objective of this work was to evaluate sulfur doses in coverage with and without fertilization with organic compost in the planting in the production and physiological quality of lettuce seeds and macronutrient extraction. Ten treatments were evaluated, in a 5x2 factorial scheme (five doses of sulfur in coverage x with and without addition of organic compost), in the experimental design of randomized blocks, with four replications, containing five plants per plot, three of which were useful. The doses of sulfur in coverage were 50, 100, 150 and 200 kg ha- ¹ of S, in addition to the control (dose 0). For the treatments with organic compost the dose of 70 t ha-1 (moist base) was used. The following characteristics were evaluated: leaf chlorophyll content, seed production (in weight and number per plant), seed quality (one thousand seed weight, first count in the standard germination test, germination, germination speed index, emergence speed index and seedling rate emerged on the 7 th day after sowing), and content and accumulation of macronutrients in seeds. The application of organic compost in the planting (70 t ha-1 ) increased seed production by 43% in relation to non-use. There was no effect of sulfur doses in coverage or application of organic compost before planting on seed quality. The mean decreasing order of nutrients accumulated in the seeds was ... / Doutor

Orientador: Rogério Peres Soratto / Resumo: Dentre os nutrientes que mais limitam a produtividade da cultura da batata (Solanum tuberosum L.) está o fósforo (P). Esta cultura tem respondido à adubação fosfatada com incrementos na produtividade até altas doses, principalmente em solos com baixo teor de P disponível, que é uma característica dos solos tropicais brasileiros, os quais são naturalmente deficientes em P. A fim de melhorar a eficiência de aplicação do adubo fosfatado, é possível utilizar fertilizantes contendo substâncias húmicas (SH) ou aplicá-las diretamente no solo. No entanto, o efeito da aplicação de SH pode depender dentre outros fatores, da textura do solo, que interfere na retenção do P. Portanto, o objetivo do presente estudo foi avaliar o efeito da aplicação de SH e doses de fertilizante fosfatado sobre a nutrição, acúmulo de matéria seca (MS), crescimento radicular, absorção e exportação de nutrientes e produtividade de tubérculos da cultura da batata, em solos de diferentes texturas. Esta pesquisa foi desenvolvida através da condução de quatro experimentos, dois em casa de vegetação e dois em campo. Dois dos experimentos foram realizados em solo de textura arenosa (um de casa de vegetação e um de campo) e os dois demais em solo de textura argilosa. Em todos os experimentos, o delineamento experimental utilizado foi em blocos ao acaso, no esquema fatorial 4 x 3. Os tratamentos consistiram de quatro doses de P (10, 50, 100 e 200 mg dm-3 de P nos experimentos de casa de vegetação; 0, 100, 200 e 40... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Plant roots are central to C- and N-cycling in soil. However, (i) plants differ strongly in tissue recalcitrance (e.g. lignin content) affecting their mineralization in soil, and (ii) rhizodeposits also vary strongly in terms of the metabolites that they contain. Therefore, (i) we used 13C labelled ryegrass root and shoot residues as substrates to investigate the impact of tissue recalcitrance on soil processes through controlled incubation of soil, (ii) we assessed variations in root C-deposition between barley genotypes and their respective impacts on soil processes using 13CO2 labelled plants, (iii) using 13C/15N enriched ryegrass root residues as tracer material, we investigated the impacts of barley genotypes on mineralization of recently incorporated plant residues in soil and plant uptake of the residue-derived N, and (iv) we applied a quantitative trait loci analysis approach to identify barley chromosome regions affecting soil microbial biomass and other soil and root related traits. In the first study, addition of root residues resulted in reduced C-mineralization rates, soil microbial activity and soil organic matter (SOM) priming relative to shoot residues. Planted experiments revealed (i) genotype effects on plant-, SOM- and residuederived surface soil CO2-C efflux and showed that incorporation of plant derived-C to the silt-and-clay soil fraction varied between genotypes, indicating relative stabilization of root derived-C as a result of barley genotype, (ii) that plant uptake of residue released N between genotypes was linked to genotype impacts on residue mineralization, and (iii) barley chromosome regions that influence plant-derived microbial biomass C. These results (i) suggest that greater plant tissue recalcitrance can lower soil C-emissions and increase C-storage in soil, and (ii) demonstrate the barley genetic influence on soil microbial communities and C- and N-cycling, which could be useful in crop breeding to improve soil microbial interactions, and thus promote sustainable crop production systems.

The forest floor is one of the components of the forest ecosystem, which significantly affects the composition of the soil and thus significantly affects the productivity and stability of forest habitat. The quality and quantity of humus and humus substance (HS), viz. humic acids (HA) and fulvic acids (FA), is an important soil characteristic. The diploma thesis evaluates the quality and quantity of soil organic matter (SOM) /stock of forest floor; the content and supply of the total carbon and nitrogen, C/N ratio; the content and supply of the total carbon in humus substance (HS), humic acids (HA) and fulvic acids (FA); Q4/6 ratio and the degree of humification/ in spruce stand at an age of 35 years in second generation and beech stand at an age of 45 years in first generation after spruce stand on the field research station Rájec-Němčice of the Drahanská vrchovina Upland (49°26''31''N and 16°41'30''E) in the Czech Republic on the modal oligotrophic Cambisol of a fir-beech forest vegetation zone at an a altitude of 600--660 m at sites of autochthonous mixed forests. Results obtained showed that the higher accumulation of forest floor was determined under the spruce stand than under beech stand. The HA/FA ratio is higher in the spruce stand as against the beech stand where young fulvic acids. The ratio Q4/6 is more favourable in the F layer under spruce stand, in the layer H is more favourable in beech stand and in the Ah horizon is the ratio Q4/6 similar. Degree of humification SH I and II is similar in both stands, appears to be more favourable in the stand of beech. Results obtained prove the suitability of beech distribution to the present sites of extensive spruce monocultures of Central and Eastern Europe in order to return to original mixed stands.