Words by Richard Rennie
Learning to manage and match their farm’s nitrogen demand to its inputs has gone a long way to explaining how Ruralco director Tony Coltman and his wife Dana Carver claimed the supreme award in this year’s Canterbury Farm Environment Awards.
Tony and Dana are equity partners in Canlac Holdings at Dunsandel. After recent expansion, the property now milks 2,150 cows in two farm operations, averaging 500kg milk solids a cow. Dana also works as the manager for DairyNZ’s StepChange project, helping farmers increase profit on a reduced environmental footprint.
The couple are quietly happy about picking up an award which Tony says has recognised the hard work and thought they have put into lowering their farm’s environmental footprint over the past few years.
Meantime they, along with other regional winners, await the supreme award announcement later this year. However Tony says nothing changes what they continue to practice every day.
“We tried to approach the award judging holistically, emphasising that we are taking a whole farm approach that includes staff, water and the environment and that being sustainable is not just about environmental management. It also includes people and financial stability. It seems the judges got that too,” says Dana.
In recognition of their inclusive approach to all the resources they tap into for the business they also picked up the Bayleys People Award, DairyNZ Sustainability and Stewardship Award, Synlait Climate Stewardship Award, and the WaterForce Wise with Water Award.
The regional environment award win has recognised the way they have managed the challenge of lowering nitrogen losses in particular.
Today Canlac leads the way in significantly lightening its environmental footprint, putting it years ahead of where the regional plan requires farms to be by 2022.
Under that plan, farms are required to reduce nitrogen levels by 30%, but the couple’s efforts have Canlac now down by 48%.
“It all started when I realised environmental management was not my strong point, but that rather than standing outside throwing rocks at what was coming it was far better I get involved,” says Tony.
The couple have taken a multi-pronged approach to dealing to nitrogen losses, but the initial move was looking at what would deliver the “best bang for our buck.”
That was to shift irrigation systems away from the older Roto-Rainers to more precise centre pivot application. With that has come an expansion of the farms’ area covered by effluent irrigation. This has included adapting the centre pivots to be capable to distributing effluent either across both farms, or separately.
“It is also helping to build up fertility on the second farm we have bought into the operation, and ultimately will enable us to further reduce the amount of synthetic nitrogen required,” says Tony.
Reducing the level of protein as a percentage of the herd’s diet also means they have lowered the amount lost as nitrate in effluent. The couple have increased the non-protein component of the herd’s diet by bringing in maize silage and beets, boosting the carbohydrate ratio of the energy intake.
They have also worked on lengthening the pasture round, with fewer grazing events necessitating lower nitrogen application post-grazing.
“So we now tend to work on a ‘little often’, which has seen us reduce nitrogen application amount by a third.”
The property is also a participant in the Forages for Reduced Nitrate Leaching (FRNL) trials, a cross-sector study aimed at building knowledge around forage production that will help lower nitrate losses by 20% or more from dry-stock, arable and dairy farm operations.
A high-profile part of the trial is the use of plantain grasses in the pasture sward. Plantain is known for its ability to absorb nitrates, and for its diuretic properties. Once eaten it tends to dilute the nitrate component of livestock urine, reducing its nitrogen potency once excreted.
Tony cautions plantain plays a role but is by no means the silver bullet often desired when dealing with problems like nitrogen losses.
“The research behind it is good, but there are issues around the practicality of getting it established, and of keeping it established in the pasture mix.”
Utilising all these tools over the past four years has meant Canlac has not had to sacrifice its 4.2 cow per hectare stocking rate, and per cow production remains an enviable 500kg milk solids a head a year.
Dana says their efforts have focused more around matching the supply or input of nitrogen, to the farm’s ability to absorb it, something heavily influenced by the time of the year.
It has meant any adjustment in stocking rate that does occur comes at the “at risk” period of May to winter as cooler temperatures lower nitrogen absorbing ability – as cows are dried off they are wintered off the farm and the couple avoid nitrogen application over that period.
“The 48% reduction has given us a good nitrogen buffer, our next focus will be addressing green-house gases,” says Dana.
These may prove an even greater challenge than nitrogen reductions.
“We need to be careful the adjustments to reduce green-house gases don’t lead to a drop in farm profitability that isn’t sustainable. I’m concerned about whether we know enough yet about how to achieve this. However, as a sector we need to continue to strive to work towards producing an environmentally friendly product.”
Dana is particularly proud she and Tony also won the Bayleys People Award, and it reflects their efforts to also take their staff with them on their environmental pathway.
“We have seen staff go from viewing our practices as ‘something they have to do’, to taking a real interest in it. They see that people outside of farming care about this, and if they leave us they leave with skills they can take to their next role in the industry. I think it will become more of a selling point for employment with farmers over time.”
Tony who is a board member of Ruralco says he is particularly proud to pick up the award in Ruralco’s first year of award sponsorship.
“Ruralco as a co-operative is going to a lot of effort to ensure it is following through with best practice. It is a very genuine partnership and to be involved with a national award is very appropriate, given Ruralco is also a national co-operative.”