Avaliação da eficiência operacional na operação de colheita mecanizada em lavouras de arroz irrigado

Abstract

The objective of this thesis was evaluate the efficiencies of the harvesting operation in rice fields, located in the region of Depressão Central do Rio Grande do Sul. As specific objectives, this study sought to determine and evaluate the following efficiencies: field, time, field pattern and cutter bar; to verify if there is difference between the areas with land level and without it; compare the field efficiency found on this study with the efficiency established by ASAE D497 4 (2009b); To evaluate the influence of the geometry of land leveling fields on field efficiency; listing the variables that have more correlation with the reduction of the efficiencies and indicate actions that may will optimize the efficiencies evaluated. In the summer of 2008/2009, 19 operations were evaluated, shared in six farms, A, B, C, D, E and F, being fifteen fields of them with land level and four without land level. The operation data were collected manually, through the use of stopwatch, a clip board to record observations and with a signal receiver of GPS (Global Positioning System), Garmin® brand, model GPSMAP® 60CSX. For helping to analyze and calculate the efficiencies, the following variables were determined: area and ratio length/width of the fields, average harvest speed, ratio distance/turning and time spent in the operation. The field efficiency was calculated through the methodology used by Grisso et. al. (2002), and have been found the average of 65,2%, that being within the variation proposed by ASABE D497.4 (2009b), the time efficiency was determinate based on the concept of Hunt (2001), have been determined a average of 75,7%, to field pattern efficiency, had been used the methodology of Perin (2008) and was observed a average of 72,0% and for calculate the cutter bar efficiency was used the equation proposed by Taylor et. al. (2001), and have been found the average of 86,5%. There was no significant difference, at 5% probability of error, between the two methods studied in this thesis (with land level or without it). The time spent in maneuvers and unloading were the most important factors that influenced the field and time efficiencies. The efficiencies of field pattern and the cutter bar had a high correlation between themselves and the variables ratio of length/width of the field and distance/turning. Making unloading with the combine in operation and if possible avoid turning in the corners of the fields, even if this make to loose in efficiency in the cutting bar, can increase the field efficiency.