Effect of pneumatic tire pressure and deformation parameters on decreasing soil compaction

Soil resources are limited and irregularly distributed around the Earth, that is why soil degradation, and, especially, soil compaction, is one of the top priority topics, which the world organizations are paying more and more attention to. Soil compaction causes are mostly related with using heavy agricultural machinery. In turn, for agricultural machines, the most important factors are the mass and dimensions of the contact area for wheels. The length and tire width are responsible for the contact surface. In modern agricultural technology the length parameter can be adjusted by changing the tire pressure. In terms of minimizing compaction, the greater the pressure, the larger the contact surface, therefore, the tractor mass is better distributed. However, the structural parameter is also important, which satisfies the condition of no folding of tire. If this parameter is satisfied, we can get reliable working of the tire throughout the entire period of operation. Experimental research was carried out on the field conditions in the centre of Lithuania, near Kaunas. For determination of soil compaction, a heavy tractor was used with approximately 30 t mass and automatic tire pressure changing technology. Using the previously proposed model for describing the tire using the properties of Cassinian ovals, it was possible to find that for the found angle 48° the optimal tire pressure should be 1.2 bar at a moisture content of 13.14%, a soil temperature of 18 ºC and a soil electrical conductivity of 123.75 mS·m-1 . This will help minimize compaction and satisfy the no folding condition for pneumatic tiresVytauto Didžiojo universitetasŽemės ūkio akademij