The present invention is directed to a twin-row planter configured to plant different seed types in different zones of an agricultural field. The planter may be a bulk-fill planter having multiple row segments with a pair of row units and a corresponding pair of seed meters at each row segment respectively receiving seeds of a first and a second type from centrally located compartments of a bulk fill tank(s) for planting in the different zones. A control system controls the planter to plant seeds of the first and/or second seed type based on which zone of the field the planter is planting at a given time. The control system primes the seed meters, making them ready for seed release, and maintains both seed meters at each row segment in a primed condition with the different seed types to allow for rapid switching between seed type deliveries when the planter reaches different zones of the field requiring different seed types.
