A first leg extends upward from the left frame and a second leg extends upward from the right frame to connect the legs to the beam. One or more satellite navigation receivers are associated with beam to determine a position and an attitude of the beam. One or more row units are suspended from the beam, each row unit having a first nozzle and a second nozzle, wherein the first nozzle and the second nozzle are associated with an adjustable reference position in one or more dimensions with respect to the beam.