If it's quite overgrown you could maybe ask the farmer to top it for you, or find someone local who would strim it.
I've just had that done with a bit of my land - he's coming back tomorrow to heavy strim it to the bare earth then put weed fabric on it so I can put plants in then cover with bark.
Depends what you want to do with it, but I think a bare earth policy is probably best if you can.
Then you can put in hard landscaping, raised beds, sheds/greenhouses etc