The two major fertiliser co-operatives have posted solid annual results despite volatile global supply and pricing challenges.
Grayling is a previous Young Farmer of the Year award winner based in Ashburton.
He and his wife Kim milk 3,300 cows across 830ha. Their equity partnership business model also incorporates a 50/50 share milking structure.
"I love farming, it's physical work that is also mentally challenging. I'm proud to be a dairy farmer and I want to give back to the sector and my community," he says.
"Ballance is an excellent example of the importance of co-operatives within the agricultural industry.
"How they respond to the ever-changing environmental needs of running a farm today will set the future direction for all their shareholders.
"I want to be part of that future direction setting, helpinng contribute at Ballance and also by bringing these skills back and applying them to local challenges, turning them into opportunities."
Grayling has experience in consultancyl, management and ownership in the dairy industry, with a particular interest in large scale farming. He has been on the board of irrigation co-operative, Barrhill Chertsey Irrigation (BCI), and he has also held a range of voluntary positions in community organisations.
Ballance is owned by over 17,000 farmers and growers. Chairman Duncan Coull says Grayling's 18-month role will focus on building governance experience.
"To understand how boards set and drive organisational strategy and vision, you need experience and training.
"We've created an opportunity for an associate to get involved in primary sector governance and learn through doing by being around the board table," says Coull.
There were a number of high calibre candidates interested in the associate director role, a good sign for the future of co-cooperative governance, says Coull.
"It is one thing to learn about being a board member, another to be around the table making decisions that can impact a sector for many generations."