The use-by date of flour is generally a few weeks or up to three months depending on the kind of flour and the climate. Providing fresh flour all year requires a bit of technology, too. Not nearly as much as collecting N, P and K and producing fertiliser, but not zero either.
Fertiliser is called NPK, named for the main chemical ingredients, which come from factories and mines on distant continents.
This gadget is very industrial: https://upload.wikimedia.org/wikipedia/commons/thumb/3/39/Ka...
The use-by date of flour is generally a few weeks or up to three months depending on the kind of flour and the climate. Providing fresh flour all year requires a bit of technology, too. Not nearly as much as collecting N, P and K and producing fertiliser, but not zero either.