Dogs can surely mess up a hunt, anytime from opening day through sundown on the closer. They have tremendous value in putting birds in the bag. If you're hunting without dogs, you're shooting more birds than a limit, if you're filling your bag.
I think fences are a bigger risk than broken glass, no one litters much around here, mostly because there aren't many of us to do it.
I guess here's something for you to consider: If you think the birds are concentrated in fence lines, canal banks (whatever those are) and roadside cover, you might want to see what they're concentrated like in stock dams, sloughs and weed patches out in the middle of private ground.
Thats why I bring a good pair of rubber boots when I hunt the Dakotas. I look for unpressured sloughs, cattails, WPA's
