Fertiliser type Fertiliser can come in the forms of granular, prilled or small prilled – the latter of which is cheaper to produce but is light in density and has limited spreading capabilities. When setting the fertiliser spreader rate this is one of the first characteristics required when using calibration charts or phone apps. This is a very important factor especially on spread widths of greater than 18m. Bulk density Granule density affects the ballistic potential of the granule and has a direct impact on the spread width of a fertiliser. A heavier granule will travel further than a light granule. Urea has a 25% lower bulk density than CAN (0.7-0.75 kg/L vs 1.03kg/L) – and this needs to be considered when setting the fertiliser spreader.