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