SORTING ACTION OF TINES AND TINE-LIKE TOOLS IN THE FIELD

The particle sorting and throwing action of tines and tine-like tools was compared in both the field and the laboratory. The laboratory model experiments were mostly carried out using glass spheres. In the field, particle properties, such as size, shape, surface roughness and apparent density, were more varied and handling factors, such as soil moisture content and travelling speed, were at higher levels than during the model experiments. Nevertheless, the findings in the field could be largely explained from the results obtained from the model experiments. Effects occurring during seedbed preparation, such as the incorporation of seeds, fertilizers and granulated chemicals and various methods of mechanical weed control, were considered. Sorting intensity increased with an increase in the variation of particle properties, with a decrease in moisture content of the bulk solid involved, with more forward facing and wider tines and with a decrease in forward speed. Throwing increased with an increase of forward speed, working depth and tool width. © 1979.