I'd like to see where this is written in law? It seems people who don't own land assume this.
I have seen it written in law, however exactly where that was, eludes me. We own land, and simply don't mind hunters on it. Sometimes I'll head out and chat with them, but I'm usually in orange too. I agree it is best to ask, if you don't personally know the land owner.
It has something to do with the game we are pursuing is owned by the public, and that the public can assume permission to pursue game, given that the land is not posted, fenced, or any form of closing off etc. Basically if it's an open (combined) grain field, a hunter is fully within his or her rights to assume permission to hunt game. Whether or not this is " right" I guess depends on the person, but I think it's a good thing. In my experience, if a farmer didn't want hunters on his land he would post it. If he didn't care, he would leave it open.
Take this with a grain of salt, however, as I'm from a small community, and if I were to run into the land owner, I would likely know them personally.