Kedushas Eretz Yisroel

In this post we brought 3 opinions regarding terumah bizman hazeh. The Rambam holds it's d'rabbanan now and was even midrabbanan in the times of the second bais hamikdash. The Sefer HaTerumos holds that the kedusha of the second bais hamikdash was batel after its destruction and that is why terumah nowadays is d'rabbanan. Finally, the Raavad holds that terumah nowadays is a d'orayssa.

One of the assumptions in this discussion is that the kedusha rishona (meaning the kedusha that came upon Eretz Yisroel from the times of Yehoshua) was totally batel. Thus, the question the rishonim are grappling with here is the kedusha shniya and its relationship to terumos and maasros.

However, it is not so pashut that all the dinim of Eretz Yisroel nowadays are dependent on the kedusha sheniya.

For example, the Rambam in Sanhedrin 4:6 says that as far as giving semicha in Eretz Yisroel is concerned we follow the boundaries of the olei mitzrayim (kedusha rishona) and not those of olei bavel (kedusha shniya). The Radbaz says there that the same would be true regarding burial and the mitzva of yishuv in Eretz Yisroel.

For further discussion of this issue see Sefer Nefesh HaRav and Mishnas R' Aharaon in Gittin Siman 11.