Hi Bob,
. Given that there's a horse on one,and there seems to be usable buildings,how about a livery? Setting up a business in France is,by all accounts,a nightmare and you'll have to pay your year's taxes upfront (someone correct me if I'm wrong please). There is an micro or auto-entrepaneur classification,but not sure if livery would fall into that.
You could always rent the land out to a local farmer. But with this beware,once rented out,it can be very difficult to get it back unless you have a good Notaire in the first place. Another potential use is to sell the "grass",just the grass,to someone local who wants to graze sheep etc. Failing that,dig a couple of acre lake,chuck in some 40lb carp,convert the buildings to gites and charge 300 a week for fishing!
Or,how about digging 40sq metres of veg patch,getting two weaners to bring on,half a dozen sheep,a few chickens ducks and geese,planting a small orchard,buying a couple of big freezers to store them all in and cut your yearly food bill by at least 50%? ........... Ree