It can work, but the part that is missing from most people's thoughts is the amount of self-sufficiency you need outside of farming to live such a life style. You certainly aren't going to make a lot of money doing such a thing, but you will make some if you pick the right crops. However to be able to afford everything you need you will need additional tools and skills. You won't be able to afford getting your house roofed or your tractor repaired by somebody else, you will be roofing your own shit, fixing your own tractor, you are going to want to be canning or preserving a lot of your own foods, you might need to switch to wood heat and cut your own fire wood or otherwise have a MUCH smaller house, fix and maintain your own tools and equipment, ect.
If you can do all that, it is a good sustainable life, but if the most you can do is grow some garden crops and shit, you will not be able to afford the service costs of everything else you need to survive. You won't be able to sell some tomatoes and afford all the same services as before, especially out int he country where land is cheap. It takes a lot of fuel to get in and out of the areas where land is cheap enough to do any of that also.