I found this on the Internet. If the heavy plough suggested in this text is pre-3rd Century, it raises the question if it hypothetically would have been possible to use it on the Germanic soil after a conquest by Maximinus Thrax...
"The drought crust plays an important role for agriculture. It was found extending up to 30 cm deep, while drought fissures carried sherds up to 1,50 m deep. The fields are usually ploughed before the first rains at the end of October, but the simple wooden plough, reported by Schumacher (1889) for the traditional Arabs, is hardly able to break the crust. Such a plough only opens the surface of the soil, breaking capillarity and storing moisture in the underground. In general it was thought that this ancient plough design is of advantage in semi-arid areas. But if the drought crust is not fully broken, it dissolves only slowly under the first rains and most of the water runs off (Lucke 2002). Long fields observed in ancient land use systems in Israel could point to the usage of the heavy plough, which is usually expected only in the northern part of the Roman empire (Kuhnen 1989). If the heavy plough was in use in he Decapolis, this would explain why there are no field divisions in the Decapolis region which refer to the classical rectangular system of the simple wooden plough (Lucke 2002, 2003a)."
http://atlas-conferences.com/cgi-bin/abstract/camu-06