"We've been doing a lot of study in the lead-up to the final."
Pupils competing in teams of three were tested on their practical and theoretical skills in modules including livestock breeding and genetics, farm safety, fuel storage, healthy soils, an agri-sector quiz and a race-off.
Shamus said his favourite involved checking the sprockets and fitting the chain on to a two-wheeler farm bike.
Flynn said they would not have been able to do it without support from their parents and teachers.
The trio qualified for the national final by placing third in the Otago-Southland regional final in Milton in February.
They met at lunchtime three days a week to improve their skills and knowledge.
Former teacher Kirsten McIntyre, who had been prepping the boys for the final, said they had worked extremely hard.
"I've been testing them on hundreds of agricultural-related questions."
Auckland-based business graduate James Robertson won the main competition, which was also contested by southern farmers Alan Harvey, of North Otago and Matt McRae, of Mokoreta, in Southland.