Traditionally, the performance of fertilizer spreaders is assessed using a row of collection trays aligned perpendicular to the driving direction of the tractor. For precise calibration of the spreader this technique, however, does not provide adequate insight into the spreading process since particle distributions are measured in only one spatial dimension. In this paper, two different two dimensional spread pattern determination techniques (SPDT) were tested, each consisting of a sampling method and a matching interpolation algorithm. Tests were executed under similar conditions with three commonly used types of fertilizer (CAN, NPK, KCl) with different physical properties. Results were compared with the traditional technique. The differences found illustrate the importance of using an adequate SPDT to compare spread patterns.