There are forecasts the number of dairy cows in Canterbury could decline by up to 20% over the next 20 years, depending on how regional councils implement National Policy Statement on Freshwater (NPS-FW) limits on the use of synthetic nitrogen and controls on leaching.
The NZ dairy herd increased 82% between 1990 and 2019, with some of the largest increases in Canterbury and Southland. Neal Wallace investigates the future of dairying in those regions and talks to some innovators who are confident that with the use of technology and management changes, dairying has a future.
The impact of the Government’s new freshwater regulations could invariably end dairying in Southland or result in a 20% decline over 20 years, depending on who you talk to.
Similarly, there are forecasts the number of dairy cows in Canterbury could decline by up to 20% over that period, depending on how regional councils implement National Policy Statement on Freshwater (NPS-FW) limits on the use of synthetic nitrogen and controls on leaching.
New regulations limiting nitrogen use will require changes, worrying farmers, especially in Canterbury and Southland, where dairy expansion has made nutrient loss to waterways an issue.
Existing management and new technology is already available to halve nitrate and nitrogen losses, lessening the impact of living with annual synthetic nitrogen limits of 190kg/N/ha.
Councils are consulting on the degree of reduction required.
Environment Southland has started consulting on proposals that will mean an average 70% reduction in each of total nitrogen (TN) and total phosphorus (TP) over all catchments, targets labelled unrealistic by Ivan Lines, an Invercargill dairy adviser with AgriBusiness Consultants.
“At a minimum it will mean massive change. At worst, it will bring a complete end to farming in Southland,” Lines said.
He said those targets equate to a pre-human state and will make even sheep farming impossible.
A regional forum is to report back later this year on limits and implementation, but a 25-year phase in for new nutrient limits and technology will temper any decline in Southland cow numbers, Environment Southland chair Nicol Horrell said.
He estimates numbers could fall by 20% over the next 20 years, the decline primarily driven by improved per cow production and management decisions rather than by new nutrient limits.
Acknowledging some requirements are confronting, Horrell said technology will assist, citing an analogy where sheep numbers more than halved but meat production has been maintained.
The degree of the herd decline depends on the response of farmers and input from the industry-funded Southland Dairy Hub, which he said will provide specific advice for southern conditions.
Environment Canterbury (ECan) planning manager Andrew Parish says the NPS-FW will be incorporated by council by December 2024 and new limits are still being discussed.
In the Waimakariri catchment, for example, it is looking at a 30% reduction in nutrient loss by 2040 and 36% in the Hinds catchment by 2033.
By setting parameters in an output-based regulatory system, Parish said farmers can continue to farm.
“We are not specifying any land-use change if they can pursue a line that will lead to lower output streams from good management practices,” Parish said.
Canterbury consultant Charlotte Glass from AgriMagic said the expectation the milk price will stay elevated for several years will ease the transition.
Similarly, the soaring price of urea will dampen demand and force farmers to look at other options, including using supplementary feed.
“Thirty years ago, we learnt how to use nitrogen fertiliser. Reducing its use is not the end of the world,” Glass said.
She said dairy farmers have repeatedly shown they can adapt quickly, and there is no reason that will not happen with this challenge.
“I think dairying is quite well-positioned into the future and there is no reason for it not to be,” she said.
Ministry for the Environment’s director of policy implementation and delivery Sara Clarke said limits on nitrogen use will mean fewer dairy cows.
“Southland, Otago and Canterbury will look different, but it was different 20 years previously,” Clarke said.
It will be up to communities to determine the extent of those changes.
“The people of Southland are the best people to think about how they will transition,” she said.
The environmental impact of dairying has become politicised and Clarke said the views of critics have to be balanced by those of rural communities, which will not please everyone.
DairyNZ strategy and investment leader Dr David Burger said one strategy showing promise, is the organisation-led $22 million Plantain Potency and Practice Programme (PPP), which research has shown use of plantain pastures has the potential to reduce losses by 37%.
“Modelling by DairyNZ forecasts a potential reduction of 15,000 tonnes a year in nitrate-nitrogen leached on 4200 NZ dairy farms in nitrogen-sensitive catchments per year by 2035,” Burger said.
Jeremy Savage, a farm consultant with McFarlane Rural Business and also the demonstration lead at the South Island Dairying Demonstration Centre at Lincoln, said DairyNZ and AgResearch research implemented on the Lincoln University Dairy Farm shows nitrogen losses can be halved.
Nitrogen losses have reduced from 72 to 36kg/N/ha a year through lower stocking rates, using less bought in supplementary feed, applying less nitrogen and culling cows in early autumn before the weather and ground conditions heighten the risk of leaching from cow urine.
The stocking rate on the Lincoln farm has been cut by 0.4 cows/ha and synthetic nitrogen application reduced from an average of 300 to 160kg/ha/a year, but Savage said production per cow has actually increased, from 430 to 500kg/MS/cow.
He attributed that increase to more careful pasture and stock management to compensate for less synthetic nitrogen and supplementary feed.