Ergonomic assessment of a battery-operated spinach harvester with on field packaging machine

The present study evaluated the ergonomic performance of a battery-operated spinach harvester equipped with an on-field packaging unit under field conditions in middle Gujarat, India. Ergonomic parameters including heart rate, oxygen consumption, energy expenditure, and subjective comfort rating (CR or ODR scale) were measured at three forward speeds (1.0, 1.5, and 2.0 km/h). Results indicated that operator workload increased with forward speed. At 1.0 km/h, mean heart rate was 103.9 bpm, oxygen consumption 0.505 l/min, and energy expenditure 10.6 kJ/min, corresponding to light discomfort (CR scale = 3). At 1.5 km/h, values increased to 107.8 bpm, 0.55 l/min, and 11.5 kJ/min, with moderate discomfort (CR scale = 4). At 2.0 km/h, workload rose further to 113.8 bpm, 0.62 l/min, and 12.9 kJ/min, with high discomfort perception (CR scale = 5). Based on physiological and subjective responses, the optimal operating speed was identified as 1.5 km/h, ensuring acceptable operator workload while maintaining higher field efficiency compared to 1.0 km/h. The study demonstrates that the developed harvester reduces drudgery, minimizes post-harvest losses through integrated packaging, and offers an ergonomically sustainable mechanization solution for smallholder spinach cultivation.