EFFECT OF THE VOLUMETRIC CHANGES OF COMPACTED SOIL UNDER DIFFERENT LOADS AND INFLATION PRESSURES FOR VEGETABLE ROOT CROPS (POTATO)
A methodology to estimate the volume of compacted soil as a function of inflation pressure and load for a 16.9R38 pneumatic tractor tire was proposed. The estimation was based on on-the-move monitoring of soil-tire interface pressure and the composite contact length determined from the contact pressures and the depths and widths of ruts formed in the soil. The volume of compacted soil was investigated on the face of one lug and on an under tread region between two lugs of a tire in a soft clay soil. The tire was instrumented with six miniature pressure transducers, amplifiers, and a wireless data communication system. The instrumented tire was run at a constant forward speed of 0.27 m/s, 23% slip on a soft soil, 0.48 MPa cone index, 25.6% d.b. moisture content with specific values of load, and inflation pressure. The volume of compacted soil enabled volumetric changes of compacted soil to be identified and magnified at the tire contact patch as one of the main causes of the degradation of soils after traffic pass. The volume of the compacted soil on the lug face was substantially greater than the volume of compacted soil on the under tread. The volume of compacted soil for the overinflated treatment was more concentrated at the tire lug centerline and middle position than at the edge of the tread. The volume of compacted soil for the underinflated treatment was more concentrated at the tire lug edge and middle position than center of the tread. The soil-tire interface contact pressure distributions results showed that as inflation pressure increased in over¬inflated treatment or load increased in the underinflated treatment, the stresses near the center and edge of the tire were increased in the respective treatments and trans¬ferred to the soft clay soil as a compaction increase sensed with the cone penetrometer and indicated as a significant effect on soil strength. As a result, these soil conditions can delay root extension or even prevent penetration into the subsoil, especially for root crops and, therefore, changes in the management of vehicles and their running gear will have both direct and indirect effects on the overall profitability of whole-farm enterprises.
Mohsenimanesh, A. and Ward, S.M. (2009). EFFECT OF THE VOLUMETRIC CHANGES OF COMPACTED SOIL UNDER DIFFERENT LOADS AND INFLATION PRESSURES FOR VEGETABLE ROOT CROPS (POTATO). Acta Hortic. 824, 191-198
soil compaction, cone index, inflation pressure, load