Yes thank you all; a good start.
Looks like buying say 20 acres of agri land (quite cheap) and renting back most of it to farmer(s) is the way to go. A runway is probably less than 1 acre. A shed which can be made very secure (without it being obvious from the outside) would be necessary since a plane sitting in the open will soon be vandalised.
Has anybody looked at surfacing? Presumably that would not be allowed, but what about that stuff with holes in it so the grass comes through?
Actually just grass should be fine.
AFAIK there is no reason why, for light use, a grass strip should not be flat as a pancake.
Currently I have a good setup which I am very happy with but I think most airfeld owners have half an eye (or even a whole eye) on closing the airfield and developing it... The particular field in question would be a huge prize; maybe 1000 houses and the local authority is pretty corrupt.
It's good to keep an eye on options. There are loads of private strips but even those that support several planes and have established use tend to be relatively closed communities which offer zero chance to a newcomer who hasn't been drinking with the rest of them for the last 20 years. Also most have a strong preference for short-field types e.g. Maule etc. I found this out several years ago. It's almost a masonic type community in some cases.