The U.S. military currently uses farm tractors for grounds maintenance on some bases.
Annapolis Maryland, Naval Academy has/had a dairy farm, kept their goat (mascot) there as well as conducted farming operations. There were several tractors on the farm the times I visited. The U.S military/government has had at various times dairy operations in other countries. Panama and Korea for sure.
VA hospitals conducted farming operations.
You might ask some WWII vets, but I recall conversations about the military conducting classes in mechanics and farming activities after the war ended.
Just a guess, I don't think the tractors would have been modified for war time use. Most of the construction equipment (dozers, cranes, etc.), when I was in, was utilized as it came from the factory.