A STUDY ON THE EFFECTS OF HARVESTER OFF-TRACK ERRORS ON SUGARCANE STUBBLE LOSSES

The amount of sugarcane stubble left in field is a major contributor to the total sugarcane loss in mechanical harvesting. Thus, reducing stubble height is an effective way to improve sugarcane recovery. The purpose of this study was to investigate how harvester off-track errors affect sugarcane stubble height and stubble loss. In this study, stubbles were sampled after harvesting, off-track errors and stubble weight were measured, and regression methods were used to model their relationships. Results showed an average stubble height as low as 0.16 m could be achieved if the harvester could track the crop row accurately. Based on the analysis of 33 randomly selected cane stools in the field, as the off-track error (the offset of actual harvester position from ideal position) increased from 0 to 1.46 m, the average stubble height increased from 0.13 to 1.41 m, which resulted in the average amount of stubble left in the field increasing from 0.07 to 0.80 kg. The results showed a strong positive correlation between stubble height (R-2=0.91) or stubble weight (R-2=0.89) and off-track errors. There were whole canes being completely left in the field either being missed or pushed down by the harvester when the off-track error was more than 0.76 m. Results suggest that improving the tracking accuracy during mechanical harvesting could substantially reduce stubble loss, leading to higher feedstock harvesting efficiency when using the existing sugarcane harvester.