Abstract
A theoretical analysis of the oscillating motion produced by a mechanical oscillator for the vibrating blade of a root-balling machine was carried out. The result was harmonic motion with a strong phase displacement with respect to the forcing torque of the eccentric masses; however, the amplitude can be approximately calculated by in-air motion analysis. Experiments were also carried out in order to determine the cutting torque of the blade in typical tree-nursery soil. These results, together with the indications of other literature reports, were used to propose a possible design directive