I've heard of hunters planting mixes of Brassicas as feeding plots (or bait) for deer. They can certainly stand up to cold weather once established!
I'm a fan of Bok Choy, edible stalks and leaves, produces lots of seed if you let it bolt and colelct them. That might be a good way to sow a large area inexpensively, for feeding chicken and goats.
Bok Choy is fairly expensive in supermarkets, and is best same-day-fresh, so it might be marketable.
Fancy mixes of very young leaves from several Asian Brassicas and mustards can be sold as premium salad mixes (microgreens) as a cash crop, especially if grown under plastic in winter.
http://www.johnnyseeds.com/Ass...
http://www.johnnyseeds.com/ass...
http://www.johnnyseeds.com/Ass...
http://www.johnnyseeds.com/t-g...
http://www.johnnyseeds.com/t-c...
http://www.territorialseed.com...
I don't have any experience that way, I have a really tiny yard.
