Physical Danger
Threshers eat arms for dinner. Don't let this happen to you.
There's the ever-present risk that you could be ground into someone's oatmeal. Ever read Soylent Green? Yeah, gross. It isn't likely that you become food (until you're dead, of course)—and you're not really supposed to stand in front of the big grinding machines.
But croppin' is physical work and there are inherent dangers. Even if you're The Big Man in charge and have others helping you with the bulk of the grunt work, you're still going to have to get your hands dirty. You'll be doing a lot of lugging and hauling, so hopefully you've got powerful arms and a strong back. Try doing some dips—not the kind with Lipton's onion soup and sour cream.