The legal age in England to drive a motor vehicle is 17. However considering many routes and farmland may be considered as off-road, you could technically drive a tractor at any age, as long as it is off road.
From personal experience, a friend of mine gained his license to drive a tractor at 16, and drove tractors immediately after. Therefore the driving of tractors or other farm vehicles may be permitted at a younger age, due to farms being "off-road".
Get a job, and pay your own way.
M.A.Atherton, C.W.J.Athey, M.R.Benson, G.Boycott, J.M.Brearley, B.C.Broad, G.Cook, T.S.Curtis, D.I.Gower, W.Larkins, H.Morris, M.D.Moxon, R.T.Robinson, B.C.Rose, W.N.Slack, J.P.Stephenson, A.J.Stewart and C.J.Tavare.
There is only one Pinfold in England, located in West Lancashire, grid reference SD3811. For your further information a Pinfold was a place where, in medieval times, stray farm animals were rounded up and the owner had to pay a fee to get them released