I think one could do with far less if things were optimised for nutrient retention (including human waste which often isn't allowed in many places). In fact I t

I think one could do with far less if things were optimised for nutrient retention (including human waste which often isn't allowed in many places). In fact I think it's easy to produce enough for a person on far less than 1 hectare in my experience assuming one's climate is somewhat fitting. My tiny backyard produced more than I could eat last year albeit with barely any space for me to walk between the plants. It's doing it long term without fertiliser/manure that's difficult.