Many folk use 'natural' for their produce grown the way you intend, your buyers just will have to have faith in you on that.
It's become the new uncertified word.
I will assume you mean sweet corn.
There is sometimes a few insects in grass land that really like corn (also a grass) and grass fields tend to use up a lot of N from the soil so you would need to manure or otherwise add 100 lbs or so of natural nitrogen to your field.
Can be different, just what you could run into.