Martin Kehoe Jr, 33, died instantly while changing a pipe in the molasses tank on the farm in County Wexford, Ireland.
It is not known if he was overcome by fumes and fell into the tank.
The dad-of-three had stayed at home to work the farm while his dad attended the National Ploughing Championships.
His three children range in age from 10 weeks to six.
Mr Kehoe Jr, who won the national under-28 conventional ploughing title in 2006, is a member of one of the country’s premier ploughing families.
Martin’s death has shocked the farming community as the family is one of the most prominent and best known in Irish farming circles.
National Ploughing Association Director Anna May McHugh expressed deep sympathy for the entire family stating: “I extend my deepest sympathies to his wife and three young children.
“We are deeply saddened within the farming community”.
Martin’s uncle Willie Kehoe said: "It’s terrible. Martin was the best of the best.
"It’s an unbelievable disaster."
"Everything had been going so well for Martin and the family. He had a great business going with meal and animal feeds. The business was absolutely flying."
Teagasc director Gerry Boyle expressed his sympathy with the Kehoe family.
“It does underline again how dangerous an activity farming is. It’s becoming an increasingly dangerous activity and we have to be always vigilant,” he told RTÉ News.
The Health and Safety Authority inspectors are investigating the accident.
Gardai were also present at the farm yesterday, but are treating the death as a tragic accident.
A file will be prepared by them for the coroner’s court.
The incident comes just a week after a man was killed in a mushroom processing plant in Co. Monaghan.
Two other men were hospitalised.
Emergency services were called to the factory where all three of the men were found suffering from breathing difficulties.
They were all found collapsed in a silo plant.
Gary Askin, 22, was pronounced dead at the scene while his brother Stephen and another man were taken to Cavan General Hospital.
Both men’s injuries are not believed to be life threatening.