"We treat the farm like our family farm, and it's our home,'' Mr Leslie said.
As regional winners of the Southland Ballance Farm Environment Awards, Travis Leslie and Catriona Cunningham, who have managed the Manapouri property since 2012, will be representing the region at the National Sustainability Showcase in Hamilton on June 6.
The couple hosted the judges for the final round before the national competition last week.
"We are getting used to it now, and starting to get the hang of it, but we always get a bit nervous [with the judging],'' he said.
"We have taken on board what earlier judges have said, and now we need to up the ante.
"The biggest thing is having our peers say we are doing a good job.
"We are quite chuffed about that.''
The couple hosted a field day on the 1640ha farm earlier this month and about 150 people attended.
"It was a good turnout and there was a bit of fog until the farm tour then they got to see everything.''
The couple carry about 1400 mixed age stud ewes, 3000 commercial sheep and 1650 cattle, with the main focus of the operation in its terminal sire sheep flock, FocusPrime.
They send about 500 rams to sale each December.
The lambing percentage during the past three years has been at 150% and they employ three full-time staff and two casuals.
Kepler Farm has about 80ha of protected wetlands, and they planted 10,000 plants, mainly native flaxes and manuka, as shelter and for riparian management, in the past three years.
He said manuka was indigenous to the area and grew well.
They have beekeeping on the farm, but while producing manuka honey might have some potential "down the track'', it is not one of their key drivers for planting the naturally occurring native.
They have been working with Doc to trial direct drilling of native seeds on one of their blocks, using a special drill imported from Australia.
"We don't expect to see 100% results, but if we get it right, it will be only 10% of the cost of planting out.''
One of the key features of their management has been utilising longer fescue grass cover on 600ha.
"For us it is about thinking outside the box and growing tall fescue to drive production.
"We are starting to see a few other people growing more tall fescue in the [Te Anau] basin.
"It does seem to be a trend and it is a natural way to combating grass grub.''
He said the way the fescue roots grew, it was a natural endophyte and grass grubs could not get a foot hold.
"They don't seem to damage fescue that way they do in rye grass.''
The increased grass cover also allowed all their cattle to be grass wintered, and they also winter part of their sheep flock on the long grass.
In addition to the Supreme Regional award, Kepler Farm also received the Ballance Agri-Nutrients Soil Management Award, the Massey University Innovation Award, the Predator Free NZ Trust Predator Free Farm Award and the Environment Southland Water Quality and Biodiversity Award .
