Design, Development and Performance Evaluation of Animal-Drawn Onion Digger

Background: Mechanizing small-scale farming enhances productivity and reduces labor dependency for resource-limited farmers. To address these needs, an animal-operated onion digger was developed at IIHR, Bangalore, for rose onion varieties Arka Bindu and Arka Kalyan. Designed for digging, soil separation and windrowing in one pass, it offers a cost-effective, sustainable solution to reduce labor costs and worker fatigue in onion harvesting. Methods: The onion digger features a robust design with two digging blades, a 430 mm diameter main beam, hitch rods for yoke attachment, depth control wheels, lift rods and windrows. It was evaluated using two blade designs (flat and V-shaped) at rake angles of 16o, 23o and 30o, across twelve experimental plots. The key performance indicators assessed included harvesting efficiency, draft requirements, power consumption and field capacity. Result: The V-shaped blade at a 23° rake angle achieved the highest harvesting efficiency (93.82%), closely followed by the flat blade (93.65%) at the same angle. The draft requirements ranged from 510 to 550 N, with power requirements of 0.21 to 0.25 hp. Field capacities were 0.10 ha/h and 0.11 ha/h for flat and V-shaped blades, respectively. Statistical analysis confirmed that the V-shaped blade at a 23o rake angle provided optimal draft values and maximum digging efficiency. The total cost of the digger is ₹ 6240, offering a practical and affordable solution for small-scale farmers. The animal-operated onion digger represents a transformative advancement in onion harvesting technology by significantly reducing labor costs, improving harvesting efficiency and alleviating worker fatigue.