If you want to live off your land, as the title of this thread suggests, then you'll have reject a lot of what many modern farmers are doing. Sure, you can adopt some of their best practices, but for the most part, if you want to stay out of Tractor Supply and hold on to your wallet, you're going to have to embrace a mixture of old fashioned farming along with some outside the box thinking and incorporate the best of other methods like permaculture, organic farming, aquaculture, wetlands habitat building, heirloom seed storage, gravity irrigation, drip irrigation, rainwater catchment, agroforestry, wildlife management, passive solar strategies, hydroponics, and free ranging your livestock - among many other outside the box subjects.

For instance, most modern farmers who have too many bugs will simply drive down to the farm store and drop some serious coin on pesticides. A permaculturist would just tell you that you don't have too many bugs, you just have too few guinea fowl!

I can't recommend enough that you look into permaculture. It is the best way, in my opinion, to manage the inputs and outputs from your land if money is tight and also provides the most comprehensive set of techniques to bring together garden crops, field crops, nut trees, fruit trees, berries, water storage, livestock, timber, and wild areas - all in one self supporting system that minimizes the inputs and maximizes the outputs in a way that is permanently sustainable and allows a home and family to sit at the center of it all.

With all of that said, you can see how hard it is to say how much land is required to sustain you.