Who does which? In one way, it's good for the soil to leave the ground undisturbed until March. On the other hand, leisurely working the team on nice, dry autumn days and getting the ground rough plowed for winter saves a lot of time come the first thaw, when getting in the field can be a task due to the mud and one finds oneself behind schedule in most years before the season even begins. (Not that this ever happens to me of course!)