An agricultural seeder or fertilizer having a meter device which dispenses
seed or fertilizer to a plurality of ground-engaging members. The supply
of metered seed or fertilizer to each of the ground-engaging members is
controlled via input from a GPS/GNSS satellite navigation system to
prevent the meter device delivering seed or fertilizer to selected of the
ground-engaging members which would otherwise pass over soil which has
been previously seeded or fertilized. Raising means, responsive to input
from said GPS/GNSS satellite navigation system detecting that the device
is travelling or is about to travel over areas of soil that has been
previously seeded or fertilized, is further is provided to raise the
selected ground-engaging members to which delivery of seed/fertilizer has
been prevented in order to prevent soil which has been previously seeded
or fertilized from being disturbed. A method of operating a
seeder/fertilizer implement to achieve the aforesaid is further
disclosed.