Having tried agroforestry through the EFS scheme (Every Farmer Suffers😂), I was unable to stop the sheep from interacting with the trees and damaging them and, at the 5m spec spacings, couldn't carry out machinery work.
Wishing to increase the number of trees on farm, I tried a mostly self funded plot (some trees provided by Trees on the Land) using electric fencing, and it worked. Two years later the trees remain undamaged. Simple cost effective agroforestry.
I'm currently trialling a reduction in the number of wires!