interesting how you made the Silage corn 30' rows and the regular corn like 15' rows... shouldn't it be the other way around??
extract the files and follow the folders maps/mapUS/data/foilage once in the foilage folder you'll see two maize folders and one will be labeled with a 2. Flip the names on the folders. I went back in game and my silage corn was the 15" spacing and corn was 30" spacing. Hope this helps!
example:
maize ----------> maize2
maize2 ---------> maize