A while back ( Dec 2016) I posted about the demographics of farmers, and the possibility that we might be seeing the early stages of a resettling of Americas rural areas. The article at the link seems to indicate others are seeing the same thing.
One point I did not make before, is that in addition to relearning farming with low input, sustainable techniques, many of these new urban to rural migrants were not raised on farms, so have even more to learn and will unfortunately have higher failure rates than if they had started from conventional farming.
On top of that, access to land, capital to buy land, are both hard to get. Even back in the 70s, my dad said that to be a farmer, you had to either be born to a farm family, or marry in to a farm family.
We haven't reached that point where fossil energy is cost prohibitive and human and animal labor move to the fore yet, and it may be quite a ways off, but it is inevitable. Once this trend is further along, many more farmers will be needed.