Fences should be easy to deal with. A digger can reach over and dig a trench straight through. With just a small bit of hand digging you could moleplough away from a fence in both directions.

Hedges

In some areas of the country these may be the most usual type of field boundary. Up north they are less common.

Up 'ere the usual sort of hedge incorporates a sheep-wire fence one side. A digger will make short work of making a way through at the thinnest section of hedge. The digger can probably do it all from one side by reaching over the fence.

A newly planted hedge might have a fence either side of it. That can be done the same way but is fiddlier. There will some manual work, and someone’s going to have to work inside a discontented hedge. Also you may have a bit of replanting to do.

Sometimes a scruffy piece of land will be fenced all round and will have no access. If you can get permission, you might be able to un-staple the fence at a suitable point for a digger to enter. Otherwise it’s going to have to be skirted or manually dug. (It might be worth knowing why this piece of land is so unwanted, you might find it is a protected habitat of something. In which case try and skirt it, or if you really have to go through it at least make sure it looks untouched when you’ve finished)

Sometimes a piece of land like this has no known owner. Take local advice as to whether this makes it 'anything goes' or 'no-go'.