Silly idea popped into my head. How about a farm that makes Clay on fertile land?XD
It exists! The "Clay Pit" blueprint is placed on Fertile Ground, and consumes Sparkdew (collected from the Rain Collector, a blueprint always available) to create either Clay or Reeds.
can you normally find clay that way? Isn't that somewhat what a clay deposit is about in first place?
Mind you finding clay can be a pain, so if there's logic for being able to 'extract' or grow clay out of fertile soil (even if it works like the mines in a way) I'm not against it.