We prove that Rav Nachman is wrong, and that a turnip may be lifted from the ground bottom up, from our Mishnah, which allows moving straw from a bed with Tiltul Min ha'Tzad.
Why isn't that Halachah clear from a much earlier, and more explicit, Mishnah? The Mishnah on 49a tells us that one may lift the cover off a pot which has Muktzah pieces of wool sitting on it, since the pieces will just fall off by themselves as the cover is lifted. That is the exact same Tiltul Min ha'Tzad as the upturned turnip, and it is permitted!
Q. Reese, Atlanta, Georgia
You are quite right. The Gemara certainly could have disproved Rav Nachman from the earlier Mishnah. But why should it bring a proof from afar ('mi'Merchak Tavi Lachmo', to quote a popular expression), when it can bring it from close by?
Nor would it have been appropriate to have dealt with Rav Nachman there, since the current Sugya is the one that deals with that aspect of Muktzah, whereas the Sugya in Bameh Tomnin is more concerned with Hatmanah.
Wishing you and yours a Kesivah va'Chasimah Tovah.
Kol Tuv
Eliezer Chrysler