Soybean harvest is considered a critical operation that might suffer some delays causing a reduction in crop yield or quality. Although the value of losses is unknown in the country, combine harvesters with high capacity are applied by the producers and they aim to conclude the operation as fast as possible. If the harvesters have greater capacity than the required, the fixed cost is increased, and if it is the opposite, it might reduce the crop yield. In both cases, there is a decrease in profit, which is called indirect costs. The problem of selecting the agricultural machinery is the commitment between adjusting the cost of the invested extra capital in the machine capacity in order to finish the work in the optimum date and the cost of losses by delaying the operation, seeking to maximize the net profit. Due to the crop importance and the indirect cost caused by the delay in the harvest, the aim of this study was to evaluate the influences suffered because of the delay in the fleet planning and harvest operation costs. For this purpose, a computer model in Borland Delphi 5.0 language was developed where the characteristics of the agro climatic region, the combine harvesters and the soy cultivars are included in the data entrance. The net profit is the result and it works as the indicator for the indirect cost in the operation for the selected combine harvester. The program was used in order to simulate scenarios in a property of Ponta Grossa (PR) region and the values showed that the obtained net profit is below the potential because the combine harvesters of the property work in a lower capacity.
agricultural machinery; harvest losses; simulation
