The land-use changes reduce the risk of phosphate and sediment loss and bacterial contamination and are expected to result in a significant drop in the levels of nitrogen leachate. It is also expected to improve the profitability of Pamu's development.
Rob says part of Pamu's value to New Zealand is trying new things to gain quality and environmental premiums for market advantage offshore.
In the Taupo area, that has included converting one of its dairy farms on Broadlands Rd to an organic farm producing milk powder. Another farm is being trialled as a low-input nitrogen farm. The third initiative is the use of a device called Spikey, which detects cow urine patches and helps convert the nitrogen to grass growth so it isn't lost to ground water.
Farming practices such as irrigation were also being carefully examined to assess whether they were economic, Rob said. Pamu currently has four of its Wairakei Estate farms irrigated but no plans to irrigate more. It is collaborating with the Te Arawa River Iwi Trust on real-time water monitoring from the Waikato River.
In Canterbury, where Pamu owns five dairy farms, it is looking to halve its dairy cow numbers on one farm over several years and moving to a mixed dairy and beef system to try to halve nitrogen losses.
Other company-wide initiatives were a stop to the use of palm kernel feed which led to reduced stocking rates because importing feed meant farms would stock more cows than they could grow grass for, leading to higher input costs, intensification, more urine patches and nitrogen loss, he said.
"By cutting your inputs and reducing stocking rate you reduce cost, animal wastage and maintain profitability."
While some environmental initiatives in the agricultural sector are criticised as 'greenwashing', he said he believed that the steps Pamu was taking were meaningful ones.
"We farm pretty carefully on the farms north of Taupo and it remains to be seen whether the steps that are being taken are enough. It's a work in progress and we are also learning from other top farmers in the district."
Since 2015 Pamu has an environment reference group to challenge its environmental practices. It includes Dr Mike Joy of Victoria University, an outspoken advocate for water quality. While the company and the group may not always see eye to eye, there are many things they can work towards.
"It's a really mature way of thinking, to gather your critics and give them input into your system and your business."