I have this theory.
"Kansas" is where they built the first LHC.
Large hadron collider, makes mini black holes, etc.
And one of the guys who made it, left his bag of popcorn in the freakin' thing.
So, when they turned it on, the popcorn magically reversed itself into corn.
And looooooots of it.
It spread all over this dear land of Kansas and now when you go past the sign into said place, all you see is corn.
:D
That is all.