Effect of tractor cultivation on heart rate and electrocardiogram RR intervals

Abstract. To assess the effect of tractor use on operator workload, we examined the effects of tractor type (large cabin tractor vs small open tractor) and operation (driving forward vs turning vs reversing) on heart rate and the coefficient of variation (CV) of electrocardiogram RR intervals. In a big cabin tractor, the mean heart rate was higher on reversing (82.1 bpm) than on turning, and higher on turning (79.5 bpm) than on driving forward (72.4 bpm). In the small open tractor also, it was higher in reversing (92.6 bpm) than in turning, and higher in turning (86.8 bpm) than in driving forward (83.1 bpm). Tractor operation had significant effect on mean heart rate, but the type of tractor had no significant effect. The mean CV was higher at rest (3.77%), followed by operation of the big cabin tractor (3.64%), followed by the small open tractor (2.93%), although the decrease was not significant. Our results suggest that a smaller area of land increases the work load by requiring more turns and reverses.