Avaliação de um sistema de distribuição de fertilizantes à taxa variável para a cultura do café

• Ano de defesa: 2010
• Autor(a) principal: Barros, Murilo Machado de
• Orientador(a): Volpato, Carlos Eduardo Silva
• Banca de defesa: Volpato, Margarete Lorin Lordelo, Silva, Fábio Moreira da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: UNIVERSIDADE FEDERAL DE LAVRAS
• Programa de Pós-Graduação: DEG - Departamento de Engenharia
• País: BRASIL
• Palavras-chave em Português: Agricultura de precisão; Aplicação em doses variáveis; Cafeicultura; Precision agriculture; Variable rates application; Coffee culture
• Área do conhecimento CNPq: CNPQ_NÃO_INFORMADO
• Link de acesso: https://repositorio.ufla.br/handle/1/3514

The aim of this work was build and evaluate a control system to apply fertilizers in variable rates to the coffee culture. It was realized on Resfriado Farm in Lavras-MG. As a first stage an adaptation of the variable rate application system was realize on a machine that applied solid fertilizers in fixed rates: it was used a hydraulic system compound by filter, valve eletro-hydraulic and hydraulic engine, fed by the tractor hydraulic control system. It allows vary the machine conveyor so varying the rate according to the indication of an electronic controller. That controller sends electrical signals to the electro-hydraulic valve that control the oil flow to the hydraulic engine. The second stage was the elaboration of the tests and its applications. It was realized three types of tests: the transversal deposition, that aimed determine the maximum distribution range by a linear regress equation; observe and quantify the variations between the programmed doses and the applied doses, and the effect of the gear variation (velocity) and doses variations on the system application precision. These last two objectives was evaluated by the completely randomized design in a factorial scheme; and to the significant values was applied the Tukey test in 5% of probability. The longitudinal deposition test aimed determines the equipment distribution feature in a machine dislocation row. It was evaluated by Cartesian charts with the relative frequency values; other factor evaluated by completely randomized design in a factorial scheme and to the significant values was applied the Tukey test in 5% of probability, was the behavior of the doses application in both distribution sides of the system. The tests of the work regime aimed verify the behavior of the distribution system in field condition by varying the percental of the applied doses and the programmed doses. It was observed that the value of the maximum rate of application was 3,65m; the application variation on the transversal deposition test was -2.67%. There is no variation on the application precision when doses and gears were varied. There was variation between the right and left side on the application system of 12.16%, 18.69% and 19.71% to the doses of 300, 600, and 1000 kg.ha-1, respectively. The application of the variable rate system in field condition presented an average error of -3.31%. It was considered a good precision that valid the system use to coffee culture.