Kaare, is the land owner a bud of yours? Just get him to put three bales together, like a triangle with a 4" slot on the one side to shoot out, Boom, blind that wont spook them. or you could roll them...sounds hard, but they roll. or roll them with your quad.
Personally, throwing a dark pop-up in the mix will make them take a BIG detour around you... But in reality I hope I have to eat those words shen i see the harvest pics on Saturday.