Caracterização das perdas e distribuição de cobertura vegetal em colheita mecanizada de soja

Abstract

RESUMO: O conceito de controle de qualidade nas operações inserido na agricultura é viabilizado por incidir diretamente nos principais objetivos do processo produtivo: retorno econômico e aumento da produtividade. A colheita mecanizada normalmente é realizada sem que haja controle efetivo para que a variabilidade das perdas fique dentro de padrões aceitáveis. Esta pesquisa teve o objetivo de determinar e caracterizar as perdas e a distribuição da cobertura vegetal após a colheita mecanizada da soja, por meio de ferramenta de controle estatístico de processo (cartas de controle). A média da perda de grãos total foi próxima do limite superior aceitável para a cultura da soja, apresentando alta variabilidade entre os pontos, tornando o processo fora de controle. A distribuição de cobertura vegetal manteve-se em processo controlado, com maior variabilidade onde o relevo foi mais inclinado. A utilização das cartas de controle foi eficiente na identificação dos pontos fora de controle e na avaliação da qualidade do processo de colheita. PALAVRAS-CHAVE:cartas de controle, colheita mecanizada, controle estatístico, perdas quantitativas. CHARACTERIZATION OF LOSSES AND CROP RESIDUE COVER DISTRIBUTION IN SOYBEAN MECHANIZED HARVESTABSTRACT: The concept of operation control inserted in agriculture is made possible by making a directly influence in the main objectives of productive process, economic return and increase of productivity. The mechanized harvest normally is carried out without an effective control of the variability of losses so that it maintains acceptable standards. This research aimed to determinate and characterize the losses and crop residue cover distribution after soybean mechanized harvest, using the tool of statistical process control (control charts). The average of total grain losses was near the upper limit specified for losses in soybean, showing high variation between points, and putting the process out of control. The residue crop cover distribution stayed under control process, with greater variability where the terrain was more sloping. The use of control charts was efficient to identify the points out of control and to evaluate the harvest quality.KEYWORDS: control cards, mechanized harvest, statistical control, quantitative losses. INTRODUÇÃOA colheita é a etapa desempenhada no sistema de produção agrícola que tem como objetivo retirar o produto agrícola das demais partes do organismo vegetal, em tempo hábil, tal que permita a mínima perda quantitativa e o alcance do máximo nível de qualidade (MIALHE, 1984; SRIVASTAVA et al., 1993, citados por SILVA, 2004.

Quality of mechanized coffee harvesting in circular planting system

“…The data presented distant average means and median values, and the standard deviation and the coefficient of variation were very high in all these variables that also indicated high variability of the data collected, a common fact in assessments of mechanized operations (TOLEDO et al, 2008). Only for the leaf loss variable, although its coefficient of variation was still high according to classification by PIMENTEL-GOMES & GARCIA (2002), the asymmetry and kurtosis indexes indicated normal distribution of the data, that was confirmed by the Anderson-Darling test.…”

“…Later the analysis of variance of the data and the Tukey test were obtained by the Minitab ® 15 computer program after finding the basic premises for statistical analysis. The same program was used to assess the quality of the harvest operation, following the methodology described by TOLEDO et al (2008) that assessed the statistical quality control using control charts, selected for the quality indicators with a graph for the individual observation and another for the variation in the process, obtained from the amplitude calculated between two successive observations. When an observation surpasses the upper limits (UCL) and lower control (LCL) limits, calculated based on the standard deviation for the process, it is highlighted on the control chart and the process is considered out of control, because it is under the action of special causes of variation.…”

“…However, studies are not easily found using statistical control tools in the mechanized harvesting process bearing in mind the need to widen the knowledge base to improve the coffee harvest. TOLEDO et al (2008) reported that statistical control of the process improves the quality of the process because it reduces variability, but there is no variability-free process so the solution is the search for stability.…”

Perdas na colheita mecanizada de soja: uma análise quantitativa e qualitativa

“…Para as perdas nos mecanismos internos da colhedora, não foram verificadas diferenças significativas, apesar da superioridade numérica, explicadas pelo alto coeficiente de variação. De acordo com Toledo et al (2008), as pesquisas envolvendo perdas quantitativas na colheita mecanizada têm apresentado coeficientes de variação com grande amplitude, podendo, em alguns casos, chegar próximo a 170%, atribuí-dos à metodologia empregada.…”

Quality of Mechanical Soybean Harvesting at Two Travel Speeds

“…Decreasing soybean mechanical harvesting losses is therefore necessary to increase the economic return of soybean production (Magalhães et al, 2009;Toledo et al, 2008).…”