potassium is naturally occurring in soil retard. if you aren't doing monoculture like a retarded corporate farmer you can constantly recycle it back in while drawing more from the soil and you can amend the soil with compost. there is also a way to create human waste recycling systems to add it back that way as well. this has all been figured out you're just too lazy to look at all the examples. go watch the global gardener then look up those projects and how they solved it.
Democrat