I’ve activated it 4 times. Twice from the path and twice from inside the field, although close to the path since I just wanted space for an HF antenna. On one of those occasions the farmer gave me a friendly wave from his tractor so I assume he didn’t mind.
Also, note that the parking area to the west is a real gravel car park rather than just mud and that the western half of the path is much better maintained than the eastern part, presumably because the farmer uses it.