Determination of Cassava Lifting Coefficient in a Loamy Sand Soil

Abstract

Tractor drawn cassava lifting equipment is required to be sturdy and ready to work against the soil and tuber weight at various moisture content of the soil. This however cannot be achieved if the forces working against the tool is underestimated. This reason why many imported tractor drawn cassava lifter failed when they are employed on the farm in Nigeria is because the soil properties differs considerably. The research study looked at lifting of cassava tuber from the standpoint of soil bulk density, tool geometry, angle of lifting, soil moisture content, speed of lifting and time taken to lift cassava out of the soil. The factors were expressed mathematically and the equation was solved to obtain the cassava lifting coefficient which was determined to be function of angle of lifting, weight of tuber and soil, speed of lifting and time taken to lift cassava out of the soil. Field experiments were carried out to determine the cassava lifting coefficient for loamy sand soil at varied moisture content and speed of lifting. Result showed that the highest lifting coefficient of 539,256.60 was obtained at the moisture content of 1.271% and lifting speed of 8 mm/s. The study further revealed that in loamy sand soil and at moisture content of 1.271%, the average cassava tubers and soil excavated was 23.26 kg. The force required to harvest/uproot 23.26 kg cassava tubers effectively was determined to be 5 kN for loamy sand soil.