Idk about studies, but we have a 10x20 garden plus numerous fruit trees, and it hardly feeds us for a few days look. We end up growing a lot of tomatoes, cucumber, and other stuff that can easily be canned like pasta/pizza sauce, salsa, pickles, jellies/jams, etc cuz we either can't eat it all when ripe and a lot goes bad, or we eat what we can and freeze it. We also use a lot of the stuff for our pets (making food) that's ripe but maybe not pleasant looking lol. We spent so much on a deep freezer, canning supplies, storage racks it takes a couple years to recoup the costs.

Other than that, it does feel good to be partially self-sustainable. Its also nice in the summer to walk outside and just eat stuff fresh off the vine! Plus no preservatives.

If you are interested I would recommend reading some books on permaculture. My first book was Gaias Garden which I loved. It talks about how to piecemeal increase your own sustainability starting in your own yard. It's a great first step if this is what you want to do. Overall no one person / family / farm can stand all alone we are all interconnected

You have a lot of research, practice, and failing to do. I moved to the country and have been doing small-scale farming. Self sufficiency in any short timescale is going to be basically impossible, especially if you need to rehab the land. There's also all kinds of materials you need that you probably can't produce yourself. Community sufficiency is much more important, I think.

Very realistic. You can do that right now. Lost of people around the world rely on subsistence farming.

But it's not particularly enjoyable. And you'll still be working a lot. Plants and animals don't take days off.

Have a look at permaculture for self sustainable agriculture, no need for fertilisers etc.

You'll need probably at least half a hectare to start approach food independence. But even with that you will struggle to get the bulk. Potatoes, Jerusalem artichokes, etc will be your friend there.

Depending where you live you might be able to grow most of your vegetable intake on less land, but you will also need a significant chunk of legumes for protein.

And in terms of fruit, you basically need a decent chunk of space to make a so called "food forest" where you have a mix of species of fruit trees and shrubs.

Geoff Lawton is a great resource!

Terrible idea. But it doesn't have to be all or nothing, which is something I feel often gets left out. You have loads of people dismiss the idea entirely because surviving on your own is going to be awful. Sure, having to grow EVERYTHING you eat is pretty difficult and you have no safety net. But there is a middle ground between completely abandoning society and living in the middle of a modern city.

Perhaps I would be happy in my cabin out in the country side, growing some herbs and higher value crops. But still work 1 day a week to buy all the potatoes, oats and firewood that I need. Along with having some money for infrequent purchases of tools and materials. Problem with that in the UK is that while land I would like to do it on exists and I could afford to build the cabin and everything, it would be illegal for me to live there. Its possible to get away with it for a while, people do. But people have also had their land taken from them by the local government when caught.

The big issue is things like healthcare. As long as your lucky and stay healthy its workable. Can even raise kids and homeschool. Theoretically insurance should fix the healthcare thing but. I assume your in the us mentioning amish. I know at one point medical education was one of the few things amish communities encouraged their members to go out and get. Just having a large community of many families is a big help with many medical issues. Help if your laid up especially at an important time. Keep in mind that is dependent on otherwise having a peaceful or isolated area. I mean farms and outlying areas are plum draft areas in russia.

I picked the middle ground where I have a small food garden in the summer and buy from local farmers in the winter. The stuff I can't get from locals I get from grocery stores. It's not all or nothing, but it's a great idea to tip the scales so that you have SOME independence and learn a skill or two in the process. I think your garden will be a great starting point if you expand it so that most of your needs are met there during growing season.

On top of that, one area of skills that is often overlooked is how you can develop self-sustainability by learning how to fix things. Buy stuff that is fixable, then when it breaks learn how to repair it. One easy example could be a knit that got a hole in it, a more difficult project might be fixing a pair of leather shoes or a busted computer.