Mr McKenzie, the New Zealand Ploughing Association chairman, will be one of the 30 competitors across several classes — contemporary, conventional, horses, reversible and silver plough.
The winners of the silver plough and reversible classes will be selected for the New Zealand team and compete at the World Ploughing Championships in Croatia next year.
Mr McKenzie has represented New Zealand before, ploughing against the world’s best in Slovenia and Sweden.
This weekend he will be walking behind a horse rather than driving a tractor.
He had decided to take a break from ploughing to focus on his family and farm in Clinton, when Middlemarch Ploughing Association president Sean Leslie invited him to work a plough for him on a team of two Clydesdale horses.
The new experience had been a steep learning curve.
"It’s quite different walking behind the plough than it is sitting in front of it looking at it. You get a whole different aspect," he said.
A major difference between ploughing with a horse, compared to a tractor, was the level of control.
"The clutch pedal doesn’t work near as good. It doesn’t just stop where you want it to. When you say go, it’s nothing, nothing, and then it takes off and you can’t control your speed, they go at whatever speed they want," he said.
He said he felt more connected to the land when ploughing with a horse.
"You’re walking in the dirt, behind the plough, feet in it, you know? It’s more natural and there’s a lot of history, too."
He enjoyed learning the history of horse ploughs when he helped build one for his team.
A plough for a horse was simpler than a plough for a tractor as it had fewer moving parts and dug narrower and shallower.
"It’s old school. It’s a different style of ploughing," he said.
Mr McKenzie will compete in a horse team with logging truck driver Blair Lennon, of Gore, who owns the Clydesdales, Harry and Anna.
Mr Lennon will work the horses and Mr McKenzie will work the plough.
Neither of them had competed in a horse team at a national level before.
The novice horse team had ploughed together at nearly 10 matches in Otago and Southland and had gone "quite well" at the last couple.
He reckoned a novice horse team could win a national championship.
"You never know. If you’re not in, you’ll never win," he said.
Mr Leslie, of Sutton, is part of a horse team preparing to defend their title.
"The level of competition has lifted out of sight in the last few years and you definitely have to up your game," he said.
His team includes a new member, Clydesdale horse George.
"So it’ll be fun."
Middlemarch is hosting the national championships for the first time and it was a big undertaking for a small town.
Entertainment includes market and food stalls, bouncy castles and lolly scrambles.
A dog trial demonstration will be run by the Strath Taieri Young Farmers Club, the Middlemarch Golf Club will run a hole-in-one competition and a contest will also being held by The Southern Tractor Pull Club.
The prizegiving will return to the paddock for the first time in about 15 years.
It was usually part of a formal evening dinner ceremony but organisers wanted the public to be part of it.
Gates open at 9.30am on both days and the prizegiving will be at 4pm on Sunday.
"Hopefully the public can hang around and see the champion lift the trophy."
