Definitions for "Drilled"
Planted with a grain drill. Grain drills differ from row crop planters in that they do not meter individual seeds, but drop small groups of seed in a process referred to as bulk metering. Drills plant crops in closely spaced rows (typically seven to 10 inches on center) that will not be mechanically cultivated.
trained in a skill by repetitious practice; "well-drilled in military procedures"