Thesis (Ph.D.) - University of KwaZulu-Natal, Pietermaritzburg, 2010. / Full text also available online. Scroll down for electronic link.

Thesis (Ph. D.)--University of Idaho, 2005. / Abstract. "December 2005." Includes bibliographical references (leaves 88-92). Also available online in PDF format.

Maize (Zea mays L.) is one of the most important crops in South Africa that is cultivated for food, feed and as a cash crop. Maize in the Eastern Cape is typically grown for consumption and the Province is one of the least producers owing to small landholdings, poor production conditions and pests. This study investigated: (i) the different maize cropping systems smallholder farmers practice in the Eastern Cape (EC), (ii) the major maize insect pests within the identified cropping systems, (iii) the perceptions of Eastern Cape smallholder maize farmers on the effects of insect pests, and (iv) the effects of crop residues on insect pests’ population dynamics. Four major cropping systems namely: maize sole cropping without rotations by government sponsored farmers (GCP) (94 percent), maize intercropping without rotations by independent farmers (IF) (79 percent), maize sole cropping without rotations by IF (67 percent) and maize intercropping without rotations by GCP (61 percent) were identified. The choice of a cropping system by the smallholder farmers was significantly influenced by source of sponsorship, the difference in their district localities, tenure system, availability of inputs and farming equipment, percentage of farmland farmers allocate to maize, maize varieties, farming experience, fallow operations and access to irrigation facilities. The major constraints faced by the farmers in maize production are the attack by insect pests, weeds competition, drought, the lack of fencing around the fields and destruction by mammals. The major insect pests identified were stalk borers (Busseola fusca, Chilo partellus), cutworms (Agrotis spp.), aphids (Rhopalosiphum maidis), bollworms (Helicoverpa armigera) and weevils (Sitophylus spp.). The most popular control measures employed were the use of GM maize and pesticides. Results from the field trial showed that field crickets were the major ground dwelling insect pests observed followed by bollworms and cutworms. However, there were no significant influence of residue retention on the insects’ diversity indices, richness, and evenness. Above ground insects sampling revealed the domination by four major insects namely, cutworms, maize stalk borer, bollworms, and spotted stalk borer. Residue management significantly influenced the infestation by spotted stalk borer only on maize plots. However, the general trend was that there was less infestation by the insects in plots where residues were retained than the ones with residue removed. Results from the study indicate that government sponsorship is significantly influencing the maize cropping systems of the smallholder farmers of the Eastern Cape.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20769号 / 農博第2252号 / 新制||農||1054(附属図書館) / 学位論文||H29||N5089(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 舟川 晋也, 教授 間藤 徹, 教授 縄田 栄治 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Doctor of Philosophy / Department of Agronomy / Charles W. Rice / Biofuel feedstocks such as grains and cellulose are gaining increased attention as part of the U.S. portfolio of solutions to address climate change and improve energy security. As the future of biofuels unfolds, major concerns are emerging, including the sustainability of the soil resource in bioenergy cropping system. With a clear understanding of the sustainability risks that exist within the agricultural soil resources, it is now essential to develop metrics that document the soil health as well as the total biomass production of different cropping system. We tested the effectiveness of eight bioenergy plant species grouped between annual and perennial crops. Our main objective was to determine the sustainability of bioenergy cropping systems. There was significantly greater soil structural stability plus greater root biomass under the perennial crops but greater aboveground biomass in the annual crop. Differences in soil carbon measured to 1.2 m were not significant between energy crops after five years. A transparent, unbiased method to identify possible change in soil characteristics under bioenergy cropping practice was offered. Our next metrics were soil aggregate stability and microbial community structure as indicators of soil ecosystem health and environmental stability. The effects 24 years of differing levels of residue and fertilizer inputs on soil aggregate stability, aggregate C and microbial community structure were evaluated. A native, undisturbed prairie site, located nearby was used as a reference in this study. The results showed that greater inputs of inorganic N and increased returns of crop residues did not cause a proportionately greater increase in SOC. The abundance of microbial parameters generally followed their potential carbon pool in cultivated soils but a strong mismatch was observed in the native prairie site. Our results showed for the first time a clear disconnect between decomposers and macroaggregates; highlighting the role of soil structure in protecting organic matter. Soil carbon sequestration is one of the mechanisms that have been proposed as temporary measure to mitigate global climate change. However, there was a particularly large risk of negative effects of mitigation measures related to the increased removal of crop residues from cropping systems for use in bioenergy, if this means that soil carbon is reduced. Effective measurement of soil C at the field scale requires an understanding of the spatial variability of soil C on a landscape scale. Recent technological advances in soil C measurement offer new opportunities in this area. Our surface measurements of soil C by near infrared spectroscopy (NIRS) provided a quick assessment of soil C and, soil C predicted by NIRS and measured by dry combustion laboratory measurements was correlated with and R-squared of 0.84.

Um dos problemas ambientais das cidades contemporâneas é a geração excessiva de resíduos sólidos urbanos (RSU), tais como os restos orgânicos, as embalagens que envolvem os produtos, pneus, garrafas, latas de refrigerante, papel, entre outros resíduos. A crescente quantidade de resíduos gerados nas diversas atividades humanas, residências, comércio, serviços e na manutenção das cidades, tem sido causada pelo modelo atual de desenvolvimento econômico, pelo crescimento acelerado da população, sua concentração em cidades e na mudança de padrão de consumo ocorrida nas últimas décadas. A gestão inadequada desses resíduos tem causado impactos negativos ao meio ambiente, porque causa danos desastrosos ao solo, ao ar e às águas superficiais carreando agentes poluentes presentes nesses resíduos, os quais infiltram no solo e podem atingir as águas subterrâneas. Neste contexto, o presente trabalho teve por objetivo avaliar a gestão dos resíduos sólidos urbanos gerados no Município de Coronel Fabriciano, localizado na Região do Vale do Aço do Estado de Minas Gerais, através de análise da situação encontrada e a trajetória municipal do inicio desta pesquisa em setembro de 2004 a dezembro de 2006. Para tal, foi elaborado e utilizado como instrumento de trabalho, o Diagnóstico Situacional de RSU para a coleta de dados da situação da Gestão Urbana Municipal, análise dos Serviços de Limpeza Urbana prestado pela Secretaria Municipal de Obras e Serviços Urbanos e, também, pelas empresas prestadoras de serviços, contratadas por essa Prefeitura e avaliação gravimétrica destes RSU. Foi escolhido este instrumento por constituir-se em uma avaliação e planejamento que objetiva direcionar as ações a serem realizadas pelo poder público e assim definir a importância e posteriormente prevenir, ou mesmo reduzir, os efeitos gerados ao meio ambiente em decorrência de falha na gestão municipal. Os resultados ambientais foram mensurados tendo como princípio norteador a Gestão de RSU, considerando alternativas de viabilidade política, econômico-financeira e institucional-administrativa e por fim, apresentar uma proposta de Política de Gestão de RSU, tendo como instrumento o Plano de Gerenciamento Integrado de Resíduos Sólidos Urbanos (PGIRSU), que busca a preservação da saúde pública, proteção e melhoria da qualidade do meio ambiente, recuperação de áreas degradada e assegurando a utilização adequada e racional dos recursos naturais para a área de deposição final a ser construída. Foram identificados avanços na gestão de RSU em Coronel Fabriciano, contudo ainda muito se tem o que fazer nessa área, objetivando minimizar os impactos negativos causados, como também atores sociais que têm cooperado com algumas das ações do poder público municipal na gestão dos RSU e atuam junto à Secretaria Municipal de Obras e Serviços Urbanos e à Secretaria Municipal de Assistência Social, a exemplo do Centro Universitário do Leste de Minas Gerais (UNILESTE-MG), responsável pelo projeto extensionista de Educação Ambiental. / One of the environment issues of contemporary residues is the over generation of solid urban residues (SUR), like organic remains, the packing around the products, tires, bottle, soft drink cans, paper and other residues. The increasing amount of residues produced in many human activities, residences, commerce, services and in the maintenance of the cities, has been caused by the current model of economical development, by the fast population growth, its concentration inside the cities and in the consumption pattern change occurred in the last decades. The inadequate management of these residues has caused negative impact in the environment because it causes outrageous damage to the soil, air and to the superficial water, carrying polluting agents present in these residues, which permeate the soil and can reach the underground waters. Therefore, the current study had as a goal, to evaluate the management of solid urban residues produced in Coronel Fabriciano Town, located in the Region of Vale do Aço in Minas Gerais State, through the analysis of the situation found and the municipal path from the beginning of this research in September 2004 to December 2006. To have it done, a Situational Diagnosis of SUR was elaborated and used as work tool for the data collecting of the Urban Municipal Management, of the Urban Cleaning Services analysis done by the Building and Urban Service Municipal General Office and also by the installment service companies, contracted by the City Hall and gravimetric evaluation of these SUR. This tool was chosen because for been in an evaluation and planning that aim to direct the actions to be done by the public authority, then define the importance and after all prevent or even reduce the effects to the environment due to the lack of municipal management. The environmental results were measured having as a guidance principle the SUR management, considering choices of political’s, economic-financial’s and institutional-administrative’s viability and finally, to present a SUR Management Politics offer, having the Integrated Management of Solid Urban Residue Plan (IMSURP) as a tool that looks up to the public health preservation, protection and improvement of the environment’s quality, recuperation of the degraded areas and guaranteeing the appropriated and rationalized using of the natural resources to the area of final deposition to be built. Advances in the SUR Management in Coronel Fabriciano were identified but there is a lot to be done in this area, aiming to minimize the negative impacts caused and the social agents as well who have cooperated with some of the actions of the municipal public authority in the SUR management and acted together with the Building and Urban Service Municipal General Office, like Centro Universitário do Leste de Minas Gerais (UNILESTE-MG), responsible for the extension project of Environmental Education.

Bibliography: leaves 105-129.

No description available.

Este trabalho tem como objetivo analisar a influencia da configuração física do sistema de espalhamento de palha em colheitadeira de grãos na eficiência do espalhamento da palha, visando cobertura mais uniforme do solo de cultivo. Tal processo produzirá melhoramentos no próximo plantio, pois espalhamento mais uniforme de palha evita perdas de nutrientes do solo por incidência luz solar, assim como previne erosão hídrica e eólica. Para analisar a influencia dos parâmetros da configuração física do sistema espalhador de palha foram realizados testes alterando parâmetros como quantidade de pás, ângulo de pás, rotação dos rotores, diâmetro dos rotores, defletor central e vazão de material. Devido à importância econômica no cenário nacional e mundial, utilizou-se a cultura de soja e os testes foram realizados em laboratório seguindo as normas da Sociedade Americana de Engenheiros Agrícolas e Biológicos (ASAE). O trabalho visa fornecer dados que auxiliem designers no desenvolvimento de novos projetos de gerenciamento de resíduos, de modo que venham a aumentar a eficiência desses sistemas, contribuindo com o crescimento da agricultura em no país. Os resultados apontam que a geometria do defletor central apresenta o parâmetro de maior influencia na uniformidade de cobertura da palha ao solo. / The objective of this work is to analyze the influence of the physical configuration of the straw spread system in grain harvester on the efficiency of the straw spread, aiming at a more uniform coverage of the crop soil. This process will produce improvements in the next planting, because more uniform straw spread prevents soil nutrient losses by sunlight, as well as prevent water and wind erosion. In order to analyze the influence of the parameters of the physical configuration of the straw spreader system, tests were performed changing parameters such as blade quantity, blade angle, rotor rotation, rotor diameter, central deflector and material flow. Due to the economic importance in the national and world scenario, the soybean crop was used and the tests were carried out in laboratory according to the standards of the American Society of Agricultural and Biological Engineers (ASAE). The work aims to provide data to assist designers in the development of new waste management projects, so that they will increase the efficiency of these systems, contributing to the growth of agriculture in the country. The results indicate that the geometry of the central baffle presents the parameter of greatest influence on the uniformity of covering of the straw to the soil.

The environmental question has been approached more frequently in our current society, the ways of structuring the consumption goods have demanded new models of entrepeneurial and environmental management, increasing the commitment and the social responsability. This study aimed to propose a system of social-environmental management for companies which offer diagnosis through images by analysing the organizational changes, related to the processes, and the administrative ones, facing the management of their residues. It is an exploratory study case with a qualitative approach aiming to develop a proposal of implementing a system of social-environmental management for companies of image diagnosis, to verify the practice developed by the company which are related to the social-environmental management, to observe the level of commitment in their human resources, to raise the necessity and benefits in implementing this system, to propose actions which allow such implementation and, finally, diagnose the obtained results from this system. The data collecting was through a non-participating observation of the infra-structure and the trajectory of the residues by using a questionnaire and informal interview applied to the member of the comission in the studied program. As a result, it was found the characterization of the residue management in all stages of the process and the descriptions of the actions involved in this process. Through the collected data by means of interviews it was identified the trajectory and the actions developed in order to implement the project proposed in the company as well as the strategies used to make people sensitive about it, the steps taken, the challenges faced, the innovations and the overcoming result from the work implementation. It was noticed the need of an interaction of the processes of environmental management related to safety, health and social responsability in business, trying to look for a better interaction and life quality. / A questão ambiental vem sendo cada vez mais abordada na sociedade atual, pois a forma de estruturação dos meios de consumo está exigindo novos modelos de gestão empresarial e ambiental, aumentando, desta forma, o comprometimento e a responsabilidade social. Este estudo buscou propor um sistema de gestão socioambiental para empresas prestadoras de serviços de diagnóstico por imagem, no qual foram analisadas as mudanças organizacionais, relacionadas aos processos, e administrativas, frente ao gerenciamento dos seus resíduos. Trata-se de um estudo de caso exploratório com abordagem qualitativa, tendo como objetivos: o desenvolvimento de uma proposta de implantação de um sistema de gestão socioambiental para empresas prestadoras de serviços de diagnóstico por imagem; verificar as práticas desenvolvidas pela empresa relacionadas a gestão socioambiental; observar o nível de comprometimento dos recursos humanos; levantar a necessidade e benefícios na implantação desse sistema; propor ações que permitam tal implantação; e, por fim, diagnosticar os resultados obtidos com a implantação do sistema. A coleta de dados foi realizada através da observação não participante da infra-estrutura e do trajeto dos resíduos, utilizando-se de questionário e entrevista informal, aplicados aos membros da comissão do programa estudado. Como resultado, encontrou-se a caracterização do gerenciamento dos resíduos em todas as etapas do manejo e a descrição das ações envolvidas nesse processo. Através dos dados coletados por meio das entrevistas identificou-se a trajetória e as ações desenvolvidas para a implantação do projeto proposto na empresa, bem como as estratégias utilizadas para sensibilização das pessoas, os passos percorridos, os desafios enfrentados, os benefícios, inovações e superação decorridos da implementação do trabalho. Foi observada a necessidade de interação dos processos de gestão ambiental, relacionados à segurança, saúde e responsabilidade social no meio empresarial, buscando, desta forma, maior interação e qualidade de vida.