What is a crop chopper?

Answer 1

A "crop chopper" if I understand what you are referring to is a machine used to harvest various crops usually for use as cattle feed. They are typically called forage harvesters or corn choppers. While they can cut and process corn for silage, they can also be set up to chop alfalfa and many other forages that would typically be fed to cattle as silage. Silage is the finished product after being put in a pit and fermented. Hope this is what you meant.