seyyed reza mousavi seyyedi

In this research, draft requirement of subsoiler tine plus fuel consumption, slippage, drawbar power, traction efficiency and overall energy efficiency of MF399 and JD3140 tractors at four speeds of 1.8, 2.3, 2.9 and 3.5 km/h and two depths of 40 and 50 cm were compared. Tractor type, speed and depth plus interaction effects had a significant effect on all parameters other than draft and drawbar power. Generally, JD3140 showed a better performance as the increase in speed from 1.8 to 3.5 km/h caused the increase of draft, fuel consumption, slippage, drawbar power and overall energy efficiency in two depths of 40 and 50 cm of 7, 4, 23, 108.3 and 89%, respectively but caused the decrease of traction efficiency of 13.8%. Furthermore, 10 cm increase in depth caused the increase in draft, fuel consumption, slippage and drawbar power of 21.3, 31.6, 20.6 and 21.4%, respectively but caused the decrease in traction efficiency and overall energy efficiency of 9.7 and 25%, respectively. The results of optimization of studied parameters using response surface methodology (RSM) show that depth of 42.9 cm and speed of 2.4 km/h resulted in the optimized condition about the performance of the tractor-subsoiler set.