Determination of Draft Force for a 3-bottom Disc Plough Under Sandy Loam Soil Conditions

This study was performed to determine the draft force for a 3-bottom disc plough under sandy loam soil conditions. The experiments were conducted using five different tractor speeds (3.6, 5.4, 7.2, 9.0 and 10.8 kilometer per hour(km)) and three tillage depths (10, 20 and 30 centimeter(cm)) with a view to determine the actual implement speed at the different tillage depths. The implement speed determined from the experiment was used to determine the draft force. The effects of tillage depths and implement speeds on draft force for the 3-bottom disc plough were investigated. The results showed that increasing the tillage depth and implement speed increased draft force and the effects appeared to be linear. At a tillage depth of 10 cm, draft force for this implement at implement speed of 0.82 and 2.58 meter per second (m/s) were 0.92 and 1.18 kilonewton (kN), respectively while at 30 cm, the draft force at 0.82 and 2.58 m/s were 3.83 and 4.67 kN, respectively. A regression equation to predict draft force for 3-bottom disc plough in a sandy loam soil was developed based on tillage depth and implement speed parameter. A significant increase in draft force at 0.05 level of significance was seen for the implement with an increase in tillage depth and implement speed. This study recommends that the root length of the crop for which tillage is made should be considered in the selection of the tillage depth.