Free images results:

Cornfield pictures, stock photos and images


Poppies Royalty Free Stock Images
Author: Belka
Fan Stock Photos
Author: Mkoh
Summer Stock Photo
Author: Rbouwman

Also, here are some commercial RF-licensed images that match your search criteria:  
Cornfield Royalty Free Stock Photography
Author: Duccio
Cornfield Royalty Free Stock Photo
Author: Mersant
Cornfield Stock Image
Author: Epantha