G. Tihanov*, G. Hristova
Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
(Manuscript received 11 June 2021; accepted for publication 26 August 2021)
Abstract. A study has been conducted for some operational indicators of a machine-tractor unit (MTU) for direct sowing of barley. The data for this study has been collected and retrieved by using the JD Link telematics system from two different fields sown with barley: field A with irregular shape and area of 13.75 ha and field B with rectangular shape and area of 16.26 ha. It was found that for both fields the values for the most monitored parameters were very close as follows: for the engine speed of the sowing unit during working stroke – 1553.65 min-1 (A) and 1586.11 min-1 (B) (the difference is <2.08%); for the idle mode of the sowing unit – 900.08 min-1 (A) and 905.63 min-1 (B) (the difference is <0.62%); for the actual working speed – 9.97 km/h (А) and 10.16 km/h (В) (the difference is <1.9%), registered when the MTU is performing the technological operation “sowing”; those parameters of MTU are nor influenced by the field size and shape. Larger differences in values between the two fields were established in terms of the relative share of engine used – 19.98% (A) and 21.55% (B) (the difference is <7.3%) and for the consumed diesel fuel (in field А it was 7.2% liters higher than in field В, respectively, 11.7% higher referring to the average diesel fuel consumption – liters per hour). The actual hourly productivity in field A was 20% lower than in field B – 3.05 vs 3.81, which is due to the fact that in the field with irregular shape – A the sowing unit made more turns at the end of the levels than in the field with rectangular shape – B.