Terumas maaser is similar to bikkurim in two ways and to terumah in two ways. It may be taken from tahor [produce] on behalf of tamei [produce], and from [produce] that is not in close proximity [to the rest of the produce], just like bikkurim. And it forbids the threshed grain, and it has a measure, just like terumah.

And there are laws which apply to bikkurim which are not so by terumah and maaser sheni: That bikkurim are acquired while attached to the ground; a person can make his entire field bikkurim; he is responsible for their replacement; and they require a sacrificial offering, song, ~waving, and staying overnight.