(perhaps subsidised as foreign farmers are)
Err, farmers are subsidised, Jalima, by the EU.
As far as I'm aware the conditions of the subsidy are that they keep their land in good heart and don't cause environmental damage with their farming practices.
Even with the subsidy many farmers struggle, mainly because we expect cheap food, an expectation encouraged by the supermarkets.
I don't know about the three crop thing; I saw it mentioned during the Brexit debate, both asserted to be restricting farmers and the assertion refuted. Can't recall details though.