In this report a numerical simulation of the interaction between soil and plough mouldboard has been performed by utilising "finite volumes" numerical approach. Simulation has been carried out by utilising a 3D-free-surface model as well as a medium soil with constitutive relationship of no- Newtonian pseudo-plastic material. As a matter of fact that "virtual" material could properly simulate either the effects of the adhesive and internal friction of the examined soil (sandy soil). Full field tests have been performed to actually validate the aforementioned experimental model. Piezo-resistive transducers have been used to detect the pressure values on 14 points located on plough mouldboard working surface. Besides, obtained pressure distribution deriving by spatial interpolation on working surface has been compared with numerical simulation data results. The maximum error detected while comparing numerical results and experimental data set has been less than 10 %. This procedure allow to study the problem of optimising geometrical shape of working surface while reducing input costs. In this way it is possible to minimize either draught force and the energy spent.