This week’s Ear to the Ground will visit an 4,500 cow dairy farm in the US, look at the obstacles for the agri-food industry caused by Brexit and see what it takes to brew beer on the side a mountain.

On tonight’s episode, Darragh McCullough visits South Dakota where he talks with Rodney Elliot who is running a dairy farm milking 4,500 cows.

Elliot sold his dairy farm in Fermanagh and moved to the US 10 years ago where he set up a 1,500 cow dairy farm.

Today the Drumgoon Farm employs 50 people, milks 4,500 cows, and produces 1m litres of milk a week.

Viewers will learn that it wasn’t all plain sailing for Elliot as the farm lost $1m (€902m) when milk prices fell in 2009.

Elliot’s dairy farm depends on cheap corn and immigrant labour, and is completely different to the 150ac family farm he sold before leaving Ireland.

“There is talk of building a wall, about having all immigrants removed from America. The reality of that situation is, were they to do that, is that there would be no breakfast on the table in America in two or three days time,” Elliot said.

Helen Carroll will visit Athlone in Co. Westmeath to meet mushroom farmer Gerry Reilly, who fears the uncertain future since Brexit could threaten his family business, which employs 70 people.

Brexit is expected to cost the Irish agri-industry €720m a year with farmers, with the mushroom industry in the front line as the UK is the single biggest market for Irish mushrooms.

“We’re 30 years building up this, and this could be just wiped out,” he said.

Meanwhile, Ella McSweeney heads to Croagh Patrick in Co. Mayo where two men are brewing a Belgian beer on a farm on the holy mountain.

Dubliner Cillian O’Móráin, who is a local vet, and Belgian Bart Adons show Ella how a normal day in their brewery goes on the side of ‘The Reek’.

Ear to the Ground will be aired on RTE 1 at 8.30pm tonight and will also being repeated on Sunday.