[Penninehillbilly]

Personally I think if you padlocked him off his own land, the average farmer would just take boltcutters to it and/or drive over the gate in said tractor, and you'd not have the lease very long..

I did suggest asking rather than just doing  -
maybe ask if you can put a padlock on gate for security? 
But best thing is to talk, which I didn't and regret.
Also I reread my first post -
putting put a feeder in the way of the access?
I was actually thinking somewhere along the track, maybe just narrowing it? not obviously obstructing the gate, sorry, it did sound bad when I came back to it.