A greenfield is a growing food source, not a bait pile.
Look at how the law defines a "bait pile" and see if your food plot fits:
...any other feed whatsoever that has been so deposited, placed, distributed or scattered as to constitute for such birds or animals a lure, attraction or enticement to, on or over the area where such hunter or hunters are attempting to kill or take themThe exceptions are defined as:
properly shocked corn and standing crops of corn, wheat or other grain or feed and grains scattered solely as a result of normal agricultural harvesting
Food plots planted as an attraction for wildlife to be hunted over fit the definition of a "bait pile" a lot better than they fit the exceptions. The difference until now has been the way the department interpreted and enforced the law.
If there ever were any valid reasons for the law to define such a crime to begin with, and I don't think there was, then those reasons have been proven not to be valid with the recent amendments.
Currently, the only difference is $15 and deeply divided opinions. Our legislators should be ashamed of themselves.