We would particularly emphasise that physical characteristics of fertiliser can vary, even within the same type and brand, due to differences in size of granules, density, surface texture, specific weight and quality of granules, etc.
These variations can influence spreading characteristics quite markedly, which result in differences in the fertiliser application rates as well as changes in spread patterns predicted in the spreading charts, therefore making it necessary to recalibrate the fertiliser.
Especially with blend fertilizers, an optimal distribution of nutrients can not be guaranteed!
To ensure greater accuracy, the unit should be recalibrated for application rate and the spread pattern should be checked over the desired width with the help of the practical test kit, every time fertiliser is changed, even when using different bags of the same fertiliser.
The calibration chart includes values for application rates normally used in pratice. The distribution of other application rates have not been tested.