Comparison of conventional tractors performance during primary tillage in Iran

Primary tillage parameters and their effects on tractor efficiency, fuel consumption management and cost reduction are very important in mechanization. The main goal of this study was to determine some performance parameters in three conventional tractors Massey Ferguson 285(MF 285), Universal 650 (U650) and John Deer 3140 (JD3140) to primary tillage practices in some area of Iran. These parameters are important for selecting tractors to set up mechanization program in a large scale. The sampling method was random in 10 regions with seven replications. After data gathering, results were analyzed using SPSS software. Results indicated that average drawbar power for plowing without considering of area and tractor type was 15 kW. The maximum and minimum drawbar powers were 19.20 kW and 11.10 kW for Esfahan and Fars areas respectively at 1% level significance. There were significant differences between values of rolling resistance of JD3140 tractor with other tractors at 1% level of significance. Besides, no significant differences were observed between tractors of U650 and MF285. Slippage percentage was similar for most areas. The maximum and minimum slippage was recorded for MF285 tractor in Moghan area and JD3140 tractor in Esfahan area respectively. The optimum soil moisture was 15% for slippage reduction. Average Power Delivery Efficiency (PDE) was 25.5%. It was low in comparison with world standards and requires improvement. Tractor of JD3140 had maximum fuel consumption (0.012 m3 h-1) as compared to other types of tractor. Use of the U650 tractor was recommended to farmer and other data can be used for mechanization programs. Keywords: drawbar power, primary tillage, slippage, primary tillage parameters, rolling resistanc