Successful planting of switchgrass using a seed drill is proven to be reliable if the proper steps are taken. Accurate drill calibration of both seeding rate and depth is essential. The calibration process is simple and can be accomplished quickly. The time and effort put forth in calibrating and adjusting the drill are vital to the successful establishment of switchgrass.
"SP701-C-Adjusting and Calibrating a Drill for Planting Switchgrass for Biofuels," The University of Tennessee Agricultural Extension Service, SP701C-2M-4/09 R12-4110-070-003-09, https://trace.tennessee.edu/utk_agexbiof/8