Hmm… That’s different, I do not have experiences with mounty areas like that. Probably are stonewalls are a better solution… (In our area the farmers builded earth-walls to mark the border of their fields. It protected also the ground from erosion.)
http://www.grossefehn-touristik.de/land-leute/das-fehntjer-land/wallhecken.html
Greetings – Heiko