You have a couple more options if you want nitrogen, without "yucky Chemicals" Composted chicken manure, Blood meal, fish meal. Personnaly I don't worry much about color as the long as the plants are making good progress. When I need it I use triple 10, or triple 13, sometimes nitrate of soda.

Blood meal is my choice. But take it easy...a little goes a long way, very light side dressing is all it takes, water in well.

Corn love 10-10-10. Heavy feeder. Short of that, lots of poop.

This will not be a popular answer, but urine. Shall I say urea just to be polite?
I have not had success with corn for other reasons, but I would think that compost and extra nitrogen would be sufficient.
This year, I am interplanting with beans, hoping that will give them the nitrogen they need.

Good luck.

Yes, once the corn has been planted with an all-round fertilizer, its next fertilizations can be nitrogen. Corn is essentially a grass or grain and has the same nitrogen needs.

I use a light application of blood meal when the corn is about knee-high and again just as the ears are forming. Others may not fertilize as often and the corn does fine, too.

I agree with everyone else - nitrogen. Some things higher in nitrogen than cow manure that haven't been mentioned yet are cottonseed meal, turkey compost & fish emulsion (or was fish mentioned?). Turkey compost is what I'm using this year for extra N - easy to spread, makes a good mulch & lasts a long time.