PERFORMANCE EVALUATION OF A THREE BOTTOM STANDARD DISC PLOUGH AT VARYING TILT AND DISC ANGLES
Ploughing which is the primary tillage operation aims at reducing the soil strength, cover plant residues, and rearrange soil aggregates. In this operation, considerable amount of farm tractor power is expended, and therefore efficient tillage system is desirable which minimizes the amount of energy required to till the soil. In this experiment, the combination of tilt and disc angle of a three bottom standard disc plough as they affect ploughing operation was studied in terms of width of cut, depth of cut, and volume of soil ploughed at a constant speed of 5.6km/hr. The test was carried out with five disc angles; 37o, 40o, 43o, 46o and 49o, in combination with five tilt angles; 15o, 20o, 22.5o, 25o, and 30o at constant ploughing length. The experiment was run at different passes of 3-blade combination maintained at 25 m ploughing length and data were taken at 5 m interval. The physicomechanical properties of the soil in the experimental plot were determined and found to be 6.7% soil moisture content (wb), bulk density is 1.53g/cm3, soil aggregate distribution of 7:1:2 (sand, silt and clay). The best performance of the three bottom standard disc plough was found at the combination of tilt angle in the range of 15o-25o, and 43o-46o disc angles. Ploughing below and beyond these values was not efficient.