Draftability Study of Non-descript Small Bullocks of Odisha for Secondary Tillage by a Four-disc Harrow

A study on the draftability of small sized Mottu (non-descript breed of bullocks of tribal districts of Odisha) bullocks (Pair weight-450 kg) for operating a four disc harrow for secondary tillage was conducted at OUAT, Bhubaneswar during the year 2009–10. The physiological responses like pulse rate in case of harrowing by four disc harrow increased with duration but the increase was sharp in the first hour and thereafter the increase was gradual. The pulse rate increased to 53.57% from its initial value after 1st hour of work. Similar trend was also observed in case of respiration rate. The average draft requirement of four disc harrow was observed to be within the draftability of the small bullocks and bullocks could sustain the load of harrowing (13.33% of their body weight) for two hours of continuous working during winter period. The field capacity was 0.047 ha/h (21.27 h/ha) compared to 0.044 ha/h (23.00 h/ha) with traditional plough. Considering draftability, fatigue score, field capacity and soil pulverization, four disc harrow ×of 510 mm width was found to be suitable for small size bullocks of tribal districts of Odisha.