Put a highly visible fence around the plot. For some strange reason, Crows won't land inside a fence, especially a new one in the area. They seem to think that it is a trap.
If you want to try shooting them, get 2 buddies to walk with you to a blind. After you're in position, have them leave slowly. Crows don't count higher than two. Three may go in, and when they see two leave, they figure everyone left. Learned this from a national crow calling champion.
Russ