There is much to read in this brilliant article so I cannot comment further, but it reminds me of the time people were asked to 'dig for britain' during the second world war.
Many allotments are still in good use.
I did this in New Zealand whilst there and cannot express the feeling when I walked into the garden, cut off a few Silverbeet and cooked them for dinner, fresh, tasty, and nourishing.
When a lot younger I never understood the value of vegetables, fruit etc. until I became sick, I'm learning fast now and I hope that someone with more expertise can set up a forum to educate us on the extreme value that this can bring to our lives.