USING THE BRIXIUS MODEL TO PREDICT TRACTION OF HEAVY SUGARCANE MACHINERY Ms C. Omar González Cueto 1 . Dr. Miguel Rodríguez Orozco Ms. C. Miguel Herrera Suárez Bs. José Antonio Ladrón de Guevara Departamento de Mecanización Agropecuaria. Universidad Central “Marta Abreu” de las Villas, Santa Clara, 54830, Villa Clara, Cuba E-mail 1 : omar@uclv.edu.cu Abstract From 1976 to 2003, 60% of sugarcane harvests in the north of Villa Clara in Cuba have been affected by heavy rainfalls, averaging 215 mm. Many interruptions to the harvesting operation have been caused by infield transport not being able to traverse the soft vertisol soils that prevail in this area. The Brixius model was used to predict the tractive performance of a New Holland 110-90 tractor with a cone index (CI) of less than 700 kPa. The main ratios and forces that characterize traction dynamics (motion resistance, net traction, motion resistance ratio, gross traction ratio, net traction ratio and tractive efficiency) were obtained as a function of soil strength and dynamic wheel load. The results showed that the RA-6 Cuban trailer can only be pulled with a CI higher than 400 kPa, working on 20 % wheel travel reduction (wheel slip). Keywords: sugarcane, harvesting, transport, traction, cone index, simulation, Brixius model