The Mishna (Shabbat 7:2) lists plowing after planting, although one must plow a field before planting. The Gemara asks why this order occurs and answers that the author of this Mishna was a Tanna living in the Land of Israel, where the ground is hard. Since the ground is so hard in Israel, it needed to be plowed both before planting and after planting. The Mishna lists plowing second, teaching that the second plowing (after planting) is prohibited. (The plowing before the planting is also prohibited, if not biblically, certainly rabbinically). The Rambam lists plowing first, and planting second.