On-the-field simulation of fertilizer spreading: Part 2 - Uniformity investigation

The results obtained were in the form of application rate maps, showing the areas of overapplication and underapplication. These areas were also characterized by the mean longitudinal and transverse application rates, which gave the application errors magnitudes. The latter were in the case of irregular fields, up to a maximum of +45%, and a minimum of −25%, around the theoretical value of 100% for a perfectly uniform area. These application errors were mainly attributable to altered ballistic flights range, caused by the difference between the tractor and spread surface inclination, and to a lesser extent, by the work of the gravity. These results allow bridging the knowledge gap around overall spread patterns uniformity on non-flat fields. They can also help in developing new active control devices.