The efficiency with which a soil can transmit energy from a traction device on a tractor to the drawbar has been called the tractive efficiency of soil.Experiments were conducted for disc ridging operations in a loamy sand soil,at tillage speeds of ... ,using trace tractor techniques. Tractive force models at different tillage speeds were developed using dimensional analysis, describing the tractor tyre- soil interaction. The measured independent variables such as drawbar pull force, rolling(motion) resistance, wheel slip, moisture content, come index, wheel numeric ,contact pressure, speed, width of ridge and height of ridge were used in the developed models.