2 acres of roaming space is plenty that I would not worry about your turks free ranging on it. The chances that there is an "active" chicken poop on 2 acres that your turkey will find is pretty darned slim (LOL)...unless you had like 100 chickens ranging that area. The virus is carried by earthworms. A chicken eats an infected worm, passes the blackhead virus and then your turkey picks it up if he eats the poop (walking thru it and cleaning off his feed will do it too). A turkey can get it from earthworms too, but since turkeys don't usually dig and scratch like chickens, they really don't munch on worms..they are more interested in crickets and grasshoppers.