Evaluation of the compaction effect and directional stability of a wheeled tractor operating on hillsides

Abstract The soil compaction induced by a tractor was studied in the field. The other aim was evaluation of the directional stability of the tractor depending on different settings of the front wheel track width. These aims were researched with the help of special tests in Armenia's highlands both on level ground and across slopes in the range of 0–10°. Despite increasing loads on the down-side wheels, soil bulk density in the wheel ruts was less on the slopes than on the level ground. It was found that at different settings the front wheel track width did not affect the directional stability of the tractor when the tractor operated across the slope. It is recommended to use the calculation of the compaction effect of tractors.