Effect of Vertical Load and Inflation Pressure of Off Road Vehicle on Compaction and Motion resistance ratio

ABSTRACT: One of the main reasons of soil porosity reduction, lower water absorption, increase in energy required for tillage, reduced root growth and therefore lower crop production is soil compaction due to tractor tires. A single tire tester designed for soil bin was used to study soil compaction and motion resistance ratio in a controlled soil environment. A 12.4-28 bias tractor tire was tested at two levels of loads (7.6 kN and 11.8 kN) and inflation pressures (83 kPa and 150 kPa) on a clay loam soil. The tire was tested with constant forward speed of 0.32 m/s, 14% slip and 15.2% d.b moisture content. Cone index, dry bulk density and motion resistance were measured. A statistical comparison was made for the cone index and dry bulk density values in the centerline and edge of the tire track. At the centerline of the tire track, inflation pressure caused significant differences in cone index and dry bulk density. With lower inflation pressures, cone index and dry bulk density were decreased in the centerline of the tire track. Also at the edge of the tire track, vertical load caused significant differences in cone index and dry bulk density. When lower vertical load in constant inflation pressure were used, cone index and dry bulk density was decreased in edge of the tire track. In addition, inflation pressure caused significant effect in motion resistance ratio.