N. Delchev1*, K. Trendafilov2, G. Tihanov1, Y. Stoyanov1

1Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Machine Engineering, Faculty of Engineering and Technologies – Yambol, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 3 July 2016; accepted for publication 23 August 2016)

Abstract. Grain tank unloading is usually done at a standstill. In some cases the combine has to leave the processed strip and to unload in a vehicle located outside the field. The publication analyses the reasons for unloading grain tanks by leaving the processed strip and the impact of this type of unloading on the combine productivity compared to unloading the grain tank in the field itself. A study has been performed in Bulgarian farms using different ways of unloading and the results of time measured for unloading grain tanks in and at the end of the field have been given when harvesting various agricultural crops. The combine productivity when unloading in the field and at the edge of the field has been compared. It has been determined that when unloading at the edge of the field the productivity is approximately 11% lower than the productivity during unloading at a standstill in the field.