Colheita mecanizada de soja : perdas e desempenho de colhedoras

Abstract

Soybeans is the crop that occupies the first place in the rank of crops grown in Brazil and it still presenting perspective of growth. This oleaginous plant is rich in protein, fiber and vitamins, being the reasons of been widely used by humans. The state of Mato Grosso is the largest producer and Brazil and there is a lack of scientific publication that addresses the problem of grain losses in the operation of mechanized soybean harvest. Therefore, the objective of this study was to conduct a survey regarding grain losses in soybean harvesting in two major producing regions of Mato Grosso and evaluate some parameters that can influence the losses, such as: different conditions of grain moisture content, working speed, platform technology and threshing system. The data was collected regions Middle-North and Northeast regions of Mato Grosso, in growing season 2012/13 and 2013/14 respectively. It was performed the characterization of the machines regarding age, manufacturer, threshing system and platform technology; as well as the general characterization of working conditions taking into account the grain moisture at harvest, working speed, and the grain losses on the platform header and total losses. It was found that, 64% of the evaluated machines presented less than four years of use. Approximately 40% of the harvesters were operating with grain moisture in the range of 19 to 25%. During the harvest 47% of machinery was running at the working speed of 4 to 6 km h-1. It was observed that approximately 60% of the evaluated machines presented total loss levels within the acceptable limit (60 kg ha-1). The draper platform presented better performance when compared to the auger type header when operating in the working speed of 4 to 6 km h-1. In the case of the threshing system, axial combines presented better performance when compared to the radial combines considering the ideal working speed of 4 to 6 km h-1). It was possible to observe that for the working speed of 6 to 8 km h-1 total losses as well as platform losses increased for both evaluated threshing system as well both evaluated plataform technology.