The numerical results obtained with SpreadDEM strongly depend on the parameters used to run the computation. Parameters such as sphericity, coefficient of friction, and even the density, are sometimes not provided by the fertilizer producer and become hard to guess. To guarantee the accuracy of the results, the use of new fertilizers may need calibration to match the experiments. Once a material has been calibrated, you can change geometries, feeding position and rate, discs speed, wind, slope and terrain height, and the results should be reliable.
In order to help you in the calibration process, here are some examples of the influence of the most important parameters affecting the results: