More than 800 exhibitors will cover the 57ha site in Waimumu, near Gore, for the three days ending tomorrow.
Southern Field Days chairman Steve Henderson, a dairy farmer in Awarua, near Invercargill, said the exhibition sites sold out in December.
"It sold out quick."
Up to 35,000 visitors were expected across the three days.
A large crowd arrived early yesterday.
Straw hats and sunscreen were essentials for a Southland scorcher.
"It’s a perfect day."
He was pleased there was a large crowd, as many farmers were battling high on-farm inflation and some were facing lower prices for their red meat.
He believed farmers would use the event to gather information and then would buy goods and services in the weeks after the event.
"That’s my gut feel — they won’t go and buy outright today."
The economic impact of the event and for the surrounding service providers would still be huge, he said.
The two-yearly event was cancelled in 2022 due to Covid.
He was "forever grateful" for the exhibitors who kept their site fee in the Southern Field Days bank account after the cancellation.
"It would have been a hell of an overdraft otherwise."
The day started with Prime Minister Christopher Luxon competing in a tractor pull event.
Mr Luxon got out of the tractor cab with a wide smile.
"That was great fun — the highlight of my day," Mr Luxon said.
The agricultural sector was the most important sector in New Zealand, Mr Luxon said.
"It is the backbone of the New Zealand economy. It drives 11% of our GDP, employs 13% of our people and feeds 40million people around the world and is 80% of our export earnings."
In a media stand-up in the middle of a fleet of John Deere tractors at the Southland Farm Machinery site, Mr Luxon was asked what he was going to do to stimulate the rural economy.
Part of his plan included doubling export revenue in the next decade, he said.
"If we get agriculture growing at 2% a year, we end up creating $35 billion of growth for the New Zealand economy."
On-farm inflation for farmers was "massive", he said.
"They are dealing with interest rates and mortgages on top of that. It is a killer and that is why we are determined to focus on the root cause of it, which is inflation."
The plan was to get the economy "aerated and moving" and roll out actions every financial quarter for the next few years.
Agriculture Minister Todd McClay was asked whether he believed National Lamb Day (February 15) would help increase the price farmers were getting for the commodity.
The lamb price has fallen due to an oversupply of the commodity from Australia.
The government would focus on reducing costs on farm, including fixing some of the unworkables regulations farmers were facing to ensure their exports remained competitive in international markets, Mr McClay said.
"Many sheep and beef farmers are not sure they can survive any longer."
