It depends on the state, but even if you have a $5m exemption on inheritance, if you inherit $10m of farmland, you need cash to keep the land (or go into debt) or liquidate the land.
No federal estate tax on $10m of farm land (kicks in around $13m this year, from what I can tell—the so-called "death tax" is often framed as applying to a whole lot more people than it actually does). Further, I'm pretty sure there are ways to structure a business that'll prevent even amounts exceeding $13m from being affected—granted, that would require advance planning which may or may not have been done.
The rest would vary state by state and depend on the relation to the deceased, but I'm pretty sure it'd be $0 or negligible in most cases, on a $10m estate, for spouse or children at least, even with minimal advance preparation.
Yeah I'm not super sure of the specifics on "death tax", haven't spent time researching it enough. It's just a topic of conversation from time to time in the family.
But the general strategy today is set up a generation skipping trust so that in the event the gov't decides to enact strict step up basis laws it doesn't blow the whole thing up.
How much is the inheritance tax?