The rotary tiller type GR 300, mounted in the rear or in the front of the tractor, is suitable as a full width tiller for an optimum seedbed preparation for the cultivation of various vegetables and potatoes. An ideal prepared seedbed is the prerequisite for optimum development of the seed resp. planting tubers. Thanks to intensive soil cultivation, the horizon for rooting is optimally prepared so that undisturbed growth of the crop can be ensured. The large number of tines and the high speed of the rotor produce a well crumbled soil structure in fields without stones. With its smaller rotor diameter the rotary tiller type GR 300 requires less tractor power as the rotary hiller GF 400. The combination with a GL 420, GL 430 or GL 420 Exacta is also possible.