Kiddushin 37: Settling the Land - with Mitzvot

Mitzvot that depend on the land only apply in the land of Israel. Mitzvot that are not dependent on the land apply everywhere. But orlah and kilayim also apply everywhere. And R. Eliezer says "chadash" - and the question is whether he is being more machmir, in adding another mitzvah to the list, or swapping it out. What does "land-dependent" mean? Because not all of these mitzvot seem quite dependent on the land! Plus, a deep dive into R. Eliezer's position, and R. Akiva's question on him.