The Government of Ethiopia is trying to improve sugar industry sector by establishing new factories, expansion projects and rehabilitation of existing ones. The main input in this process is agricultural mechanization; however it has been resulted in a huge number of farm machinery of various types and sizes, without consideration of proper selection and matching between tractors and their attachments (implements). This approach had led to high cost of agricultural operation, resulted in an unbalanced distribution of machinery and the agricultural operations throughout the years. Wonji Shoa Sugar factory is one of the victims of the aforementioned problem. The present study was conducted to evaluate the current farm machinery selection practices of Wonji Shoa Sugar Factory. Three soil types namely; heavy clay, vertisol and sandy loam were selected with four field activities (subsoiling, ploughing, harrowing and furrowing). For subsoiling, ploughing and harrowing, 9410-R John Deer tractor with implements of 5 shank and 3.2 m wide mounted subsoiler, 2.8 m wide double gang offset disc plough, and 3.5 m wide semi mounted four gangs double offset were used respectively. For furrowing YTO-1804 tractor and a four bottom fully mounted 4.5 m wide rider was used. For each experiment, the draft force requirement of the implements, the drawbar power, fuel consumption, overall energy efficiency and power utilization ratio were determined at different tractor travel speeds. Subsoiling, ploughing and harrowing were activities were evaluated at the travel speed of w 3, 4, 5 and 6 km/hr. And a travel speed of 4, 5, 6 and 7 km/hr were used for furrowing operation. Linear regression tests were run to examine the interactions between the factors and determine their significant impact. The results of this study noted for furrowing operation as lowest draft force, drawbar power, fuel consumption and energy efficiency of 14 kN, 12.65kW, 13 lit/hr and 8.7 % respectively in sandy loam soil type. The maximum Draft force of 79.8 kW and drawbar power of 131 kW was noted for subsoiling operation in Heavy clay soil. Moreover the results of all operation in all soil type, as indicated by both overall energy efficiency and power utilization factor shows the mismatch between the tractor and implements, as the tractors were overpowered. That means a less amount of the available power from the tractor is being used to operate the implement. If the tractor had been matched with a bigger and compatible implement a better efficiency and higher productivity of the tractor implement combination could have been achieved.
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