A method of studying the influence of fertilizer particle size on the distribution from a twin-disc spreader

Abstract

The object of this work was to study the influence of fertilizer particle size on the distribution from a typical spreader design. The fertilizer, spread from a stationary twin-disc spreader, was collected in square trays positioned in a regular pattern in the field covered by the spreader. Collected samples were weighed, and the particle shape and size determined by an image processing technique. Based on these results the spatial distributions of mass and particle size were determined. It is shown that the shape of the transverse spread pattern calculated from the spatial mass distribution coincides well with the corresponding shape from a moving spreader. The measured particle diameters were sorted into particle classes covering five commonly used size intervals. From the spatial mass distribution the corresponding transverse spread pattern was calculated for each of four dominating classes. A method of predicting the transverse spread pattern for a mixture of particle classes isdescribed and an example is given. To obtain continuous distributions, interpolation was performed. The distribution of particles of different sizes is visualized using three-dimensional graphics.