True, and I believe what constitutes it being legal or not is 1) is it a "normal farming practice"
2) if it is left for the wildlife, it cannot be "manipulated", ie. can't cut the crop down and just leave lay, etc.
I have a farmer leave me small patches of corn for goose blinds. I normally cut some of that corn, and slide a blind inbetween the rows. Any of the corn stalks I cut down, either to put the blind in, or if I cut some down to tie it onto the blind.....I have to take the "ear" of corn off the stalk, and take it out of the field, since that is the "food" part of it. Any of the other standing corn that is left there, that I haven't "manipulated" or messed with, can stay put with the ears on it still. That is direct from the WCO that used to be in my area.
Problem comes in when you purposely make it easier for the wildlife to get to, then it becomes baiting. Common sense, if you cut it, trample it, etc. your baiting in their eyes, imo.