At 9:20am, NSW Police and NSW Ambulance attended the scene in Buckajo where they found the man lying in the paddock.

Police state the man drove his two-wheel-drive tractor to spray blackberries in the paddock. He exited the tractor which then began to roll down hill. 

The man attempted to move out of its path but the tractor ran over his chest and knocked him unconscious. The tractor continued to roll another 150m down hill after striking the man.

The man eventually regained consciousness and dialed emergency services on his mobile phone, directing them to his location in the paddock. 

Paramedics treated the man at the scene in excess of an hour to stabilise his condition before being transported by helicopter to Canberra.

NSW Ambulance said the man sustained serious back and abdominal injuries and possible pelvis and chest injuries.

The man will continue treatment in Canberra.