Other factors besides calories per square-whatever-an-acre is, is how much fertiliser, how often does the land need to rest.
It does empty the ground of some nutrients. I love them and grew up on a small potato farm.Land should never rest/fallow, especially if it’s tilled. All you end up doing is burning off soil organic matter and adding weeds to your seedbank.
Rotational cropping is a must, preferably with a legume
Also if all you eat is potatoes you will die. They are not complete nutrition by themselves.
If you mix potatoes the only big thing you’re missing is protein. Otherwise they have a pretty good mix of every other vitamin.
There’s pretty much no food that compares.
You could mix that with a protein complete food like lentils
The article also lists other items on an area per calorie level too which is neat to see.
It does remind me a bit of this image.
Unless you’re in Ireland in the mid 1800s, that is.
How many potatoes does it take to kill an Irishman?
None.
Oh that’s dark