Development and Performance Evaluation of Tractor-Drawn Broad Bed Maker

Abstract

 Agriculture in Ethiopia is predominantly characterized by subsistence farming, where smallholder farmers primarily produce for household consumption. In Ethiopia, over 80% of the population is engaged in agriculture, with a significant portion cultivating crops on Vertisol-dominated landscapes. Vertisols, which constitute approximately 16% of Ethiopia’s highland areas, pose considerable challenges due to their poor drainage, leading to waterlogging and reduced workability. Farmers have traditionally relied on rudimentary methods, such as delayed planting and manually constructed broad beds, which fail to fully exploit the agricultural potential of these soils. This study focuses on the development and performance evaluation of a tractor-drawn broad-bed maker (BBM) to enhance land productivity on Vertisols. The research involved designing, fabricating, and assembling key components, including an adjustable ridger, shanks, frame, three-point hitch links, and a bed leveler. Performance tests were conducted to optimize operational parameters, including speed and tillage depth. The findings revealed that the optimal bed formation occurred at a speed of 2.9 km/h and a tillage depth of 20 cm. However, to reduce draft requirements, the recommended operating conditions were established at 2.3 km/h and a depth of 15 cm. Under these conditions, the developed BBM achieved an average bed height of 23.6 cm and a top width of 124.3 cm, with draft forces ranging between 265.91 kgf and 388.03 kgf. The field efficiency was determined to be 72.9%, with a wheel slippage of 6.35% and a fuel consumption rate of 3.44 L/h. The total cost of operation for bed formation using the tractor-operated BBM was calculated at 23,479.08 Birr. The study demonstrates that the developed BBM significantly improves field efficiency and operational effectiveness compared to traditional methods, making it a viable solution for mechanizing Vertisol management in Ethiopian agriculture.

Keywords: Broad-bed maker (BBM), Vertisol, Draft force, Waterlogging, Field performance