I think the question relates to something I feel strongly about, so I'll risk a reply.
The route I use most frequently for local walks begins with a PRoW farm track between arable fields. This year, the track is proving far more popular than previously; it leads to extensive woods, and is especially popular with dog walkers.
No fences separate the track and fields, and it angers me to see some owners allowing their dogs to run free across the fields (the owners generally keep to the path). At the moment, the crop is winter wheat and it doesn't seem to occur to some people that the plants can be damaged by frolicking dogs - and I really don't like seeing dogs poo-ing on crops. I've seen it happen, but I've never seen an owner bag the poo!
I hope I've not gone too far off topic - I was tempted to contribute by the dog being off the lead...
As the farmer, I'd insist the dog be kept on a standard lead and allow the walkers to keep to the field edge.