Hi, this would be a violation of rule 3: https://itch.io/jam/mundane-jam/topic/1171610/official-jam-rules
Jams are generally intended for new projects. It's cool if you want to continue working on the same project, but it wouldn't fit our (and most) jam requirements.
You're allowed to use general-purpose code, though, so if you have generic farming sim code, you can reuse that and make a new farming sim game.