The law follows the GVWR rating on the factory tag on the door post or door panel (or that general area of the vehicle) - doesn't matter how much the vehicle acturally weighs. If the vehicle is mfg'ed for under 26001lbs - no cdl is neccessary. The law doesn't look at what a person licenses the vehicle for either.     If the combination of vehicle and trailer while in use, weighs more then 26001 lbs - you need a CDL also.

If you are useing the vehicle for your own personal use, on the farm - you may get by without a commercial drivers licence. Check with your state moter vehicle office