No real surprises for me...I got nine correct answers without a single wrong guess. I then guessed North Dakota and Arkansas before getting the final correct answer (Ohio).
Corn is only growable at extreme quantities for only the easternmost 100 miles or so of Nebraska. The rest of the state is to dry and is mainly wheat fields and cattle ranching
initially surprised by oklahoma, where the wind comes sweeping down the plain, but apparently that plain is not filled with corn. I note in the source it is 27th. Also the source does not give figures for Alaska and Hawaii but I'm guessing those two are bottom of the list anyway.