fearfulfrog, could you talk to your husband and tell him how his getting upset makes you feel? Ask him if he could skip the getting upset part and just do the task, since he does do the task anyway...
Or maybe find a way to make it fun. Have a "Darn, I hate plowing" after-party. Have his favorite coffee, hot chocolate, cookies, sandwhich ready for when he's done, or a foot massage or something else that would be fun that he likes...