Ashburton dairy farmers Mark and Devon Slee are the national winners of the 2014 Ballance Farm Environment Awards.
It's the first time a dairying operation has won the top national award and they were chosen ahead of nine other regional winners.
Devon believes their efficient farming system caught the eye of the judges.
"We were able to show that investments we had made on farm in our resources, our people and our land were giving us a lot of benefits from an environmental and economic way."
The Slees, who employ 14 fulltime staff, run a highly profitable dairy business and, at the same time, ensure the environment is managed extremely well.
They milk 2500 cows on a milking platform of 624 hectares and have a particular focus on the efficient use of water and effluent.
The property is fully irrigated and, in areas where trees have been removed to accommodate the irrigation system, they've planted more than 10,000 natives to create low shelter beneath the centre pivots.
"The micro climate that the centre pivot provides with the watering has certainly suited them, so we've got Hebes, Pittosporum, Flaxes, Toetoes, Karakas, the odd broadleaf out there so there's quite an eclectic mix and they're just such a pleasure to have on the farm."