All round is change – elsewhere in this week’s Irish Farmers Journal, we go into British prime minister Theresa May’s uncompromising speech on how the UK sees itself operating outside the EU.

Last week, in Greenmount Agricultural College in Antrim, the Ulster Arable Society held a large gathering of tillage farmers from north and south of the border. While Northern Ireland’s Minister for Agriculture Michelle McIlveen came and delivered a speech of real substance, she acknowledged that with developments in Belfast that it was likely her days were numbered – she was correct.

The backdrop to the North’s and indeed to the whole island of Ireland’s tillage sector is extraordinary and a stark reminder that politics and trade agreements can have utterly fundamental effects on how sectors produce.

The Central Statistics Office is a huge unappreciated reservoir of fascinating but also instructive data.

We have all been aware of the general effect of the repeal of the Corn Laws in Britain (and Ireland) in 1846. What’s less realised are the consequences north and south. The North’s acreage under cereals collapsed from 226,000ha – over half-a-million acres in 1865 – to 33,000ha or less than 80,000 acres in 2015. The falls in the rest of Ireland were equally dramatic with a fall in wheat acreage from 327,000 acres in 1861 to just 36,000 in 1911. The drive to Irish self-sufficiency and compulsory tillage saw all of this fall recovered by the end of the 1950s but, since then, despite our very high yields and a technical revolution in Europe in the late 1970s and early 1980s, wheat has retreated to the very best land areas as new sources of cereals have emerged across the world; prices have stagnated, yields in Europe have plateaued and livestock, both bovine and pigs and poultry have grown continuously. Northern Ireland now finds itself with a surplus of phosphate generated from its intensive livestock sector and this is already giving tillage farmers an opportunity to reduce costs significantly.

At the conference, an interesting blueprint for the future was unveiled. Under the chairmanship of former UFU president John Gilliland, now agricultural director of Devenish, a new growth and sustainability blueprint for Northern Ireland agriculture has been prepared. It pulls the various strands of northern agriculture together looking at where and how the sector should be able to continue to intensify without breaching environmental constraints, but the key factor inevitably will be the type of trade, food import arrangements and safeguards for UK production put in place after Britain leaves the EU.

A similar type of exercise could usefully be done here in the south, pulling together the strands of recycling organic manure, greenhouse gas emission, production efficiency, output targets and markets with real potential. It’s probably time to revisit Food Wise 2025 already.