I am thinking of adding radon mitigation to my home, but i am also considering a dirt root celler.

Can the two coexist?

I was thinking the root cellar would be air sealed from the main home so it should work. I should only have to worry about radon in that one room i think, or rather worry most there. I dont realy plan on hanging out in the root cellar often.

Also is there ever a need to have a second mitigation hole revented to the radon stack?

Full disclosure: I have not tested but would rather be safe than sorry.