How do you trademark a broken trunk piece of Maple tree? I have a 40ft. white maple that appears to enjoy had...

I have a 40ft. white maple that appears to enjoy had a split trunk, one branch of which have been cut around 3 feet stale the ground. That cut section is hollowing out into soft wood as it collects hose from rainfalls.

Does anyone have any suggestions roughly treating that soft wood and sealing the top of the cut sour trunk so as to stop the rotting process? I am guessing the water is speeding up the rust and needs to be stopped from soaking the hollow--bugs must love this.

Thanks within advance,
Help near my plant please?
Answers:    It's a opportunity for a tree surgeon, the rotten wood needs to be cut away, you can't basically tamp the rotting section.

With it man a split trunk the crown might need harmonizing, (it split for a reason) and again it's a job for a man beside a chainsaw.