Four types can be distinguished: (1)
the properties of the artificial fertiliser particles (size and
shape, density, air resistance coefficient, friction coefficient
with the disc and the vanes); (2) the properties of
the spreader (disc shape and speed, shape and position
of the vanes, position, size and shape of the hoppers
orifice); (3) the working width; and (4) external factors
(wind, humidity, surface irregularities and mechanical
vibrations).