A land mine is defined as a weight-triggered explosive device which is intended to damage a target by means of a blast and/or fragment impact.
Assuming that a few humans manage to survive the initial onslaught of the undead when the Zombie Apocalypse begins and manage to band together for mutual support and protection, I imagine that landmines (if available) would be used to defend the perimeter of the makeshift base camp. This is actually perfect because perimeter defense is actually one of the landmine’s primary jobs: to create defensive tactical barriers.
I have several problems against landmines, however.
One is that it doesn’t discriminate against friend or foe and the other is that, once buried and setup, they have a nasty habit of being forgotten that they’re there.
Furthermore, landmines tend to remain dangerous many years after a conflict has ended, making them something else to worry about aside from the undead (as if we didn’t have enough problems by that time). These very same concerns led to a 1997 Convention on the Prohibition of the Use, Stockpiling, Production, and Transfer of Anti-Personnel Mines and on their Destruction, known informally as the Ottawa Treaty.
So, yeah. Thanks but no thanks. Give me a shotgun any day.