If most of the world is a giant plains, where's the tall grasses? I think that'd be a bit more realistic to have that. Just recolor the wheat green and make it unharvestable.
Foxes could hide in it, and maybe, if you want to find things hidden under the grass, you'd need a scythe tool to thresh it down. This could give actual grass seeds as well.
Although, currently hops/hemp are being used for that mostly.
EDIT: Adding to the grass planting, you should have to have a piece of straw to lay over it as well. Also, rain would be cool. I'm not trying to make this into a Harvest Moon thread, but I think plants should have to be watered, but it shouldn't really be tedious. Rain would just give you some time off to go do other things.