how could you maximize food production with magic items and spells over a long period of time?

Over the course of years, how would you appropriately maximize food production for a town or city? If you assume the small city/large town and its very large (100-mile radius) surrounding area can be created with this goal in mind, what spells and magic items could be useful? This should be ruling out spells that are very small individual buffs(Haste, Enlarge/Reduce etc). These options should be more efficient than Plant Growth unless they are lower level/repeatable. Creative options like the Decanter of Endless Water and similar would also be helpful!

I am asking this as a player: the premise is creating a city. Any spells are acceptable, lower magic is preferred(1-5), but higher-level options are also good to know. This question has a broader application than this related question that is only about the plant growth spell’s applicability.