Amazingly glad rag, although you own the land (and down to the centre of the Earth, should you be lucky enough to strike oil) you don't own the airspace above it!
While (I guess) this was meant to stop you charging Sqeezy Jet for overflight rights, as I understand it there's no minimum height. So legally (which is not necessarily sensibly), if properly authorised, and within an LFA, you can fly anywhere (ish), so long as you don't land.
That said, there is usually (and has to be for landing) an agreement between landowner and user. Which there normally is around rotary Stations, cos we couldn't function without them.
As I used to say in briefings:
1. Helicopters are not much use if they can only land at airfields.
2. MoD doesn't own much in the way of fields, cliffs and holes in woods!