The question of how farm funding should be divided up across the UK after Brexit has been a thorny political issue, not least because the Scottish Government in particular has been concerned about a loss of powers. It also has an ambition to continue some form of basic payment after Brexit, although that would depend on funding being available (the Welsh Government does not intend to maintain a form of basic payment).
The Government has appointed an independent panel chaired by Lord Bew to review the issue: Fair funding for farmers. Each of the devolved administrations will be represented on the panel.
It is also stated that the intention is not to maintain the Barnett formula in relation to agricultural spending after the end of the lifetime of the current Parliament.
Under the present distribution of funding, Northern Ireland does best on both a per capita and a per hectare basis: Funding for farming across the home nations