A supplemental down force system for a ground working implement is provided where the supplemental downforce system groups the row units into at least two groups and provides a different supplemental down force to the row units in each group. This enables the row unit to have a supplemental down force closer to the desired down force recognizing that the row units do not all operate in the same conditions. The controller periodically regroups the row units into the at least two groups and readjusts the down force.
