The Greenhouse Gas Partnership Farms research project worked with farmers to identify and model how their farms might reduce both nitrogen loss and greenhouse gas emissions.
“Making these gains will be the first steps as farmers work towards the government’s 2030 climate change targets,” said DairyNZ strategy and investment leader Dr Bruce Thorrold.
For some farms, the research identified options that offered lower footprint and higher profit. For already highly efficient farms, footprint gains tended to come at a cost to profitability.
“It is more challenging for farms that are already efficient. For them, it’s about where even the smallest gains can be made. Small improvements on individual farms add up at national level.”
The dairy sector is working through a process of helping farmers know their emissions profile numbers, identify options and implement solutions.
“The Partnership Farms research highlights that to reduce footprint, all farms had to reduce total feed eaten and nitrogen surplus. The findings highlight the need for ongoing research into technology to reduce footprint without reducing feed,” said Dr Thorrold.
“These technologies are required for dairy farmers to achieve the challenging Climate Change Commission recommendations. Investment in R&D and support from the government will be crucial.”
The Partnership Farms research is part of DairyNZ’s Dairy Action for Climate Change commitment to support dairy farmers and the wider sector to address on-farm methane and nitrogen emissions long-term.
The Partnership Farms modelling was carried out for six farms in Waikato, Southland and Canterbury.
The work found a strong understanding of the farm, the people and the farm system was important at the beginning. The process involved a Whole Farm Assessment and modelling in Overseer and Farmax.
Dr Thorrold said dairy farmers are committed to playing their part in addressing climate change, alongside the rest of New Zealand, and there is a wide range of work underway on farms throughout the country to achieve this.
“New Zealand is already the most emissions efficient producer of dairy milk in the world but it’s important we continue to reduce our emissions and remain the best,” said Dr Thorrold.
“It’s about doing the right thing as a sector and consumers are also increasingly demanding sustainable products.”
The next step is for DairyNZ to work more widely with farmers to start exploring their own system adaptions through its Step Change project. Step Change is helping farmers understand the options best suited to their farm and how to improve profitability and water quality and reduce greenhouse gas emissions. A series of Step Change events will start on March 10 to help farmers explore their options.
“Our regional teams are working with farmers to help them understand their starting position and then uncover the opportunities available – some of which are demonstrated through this research,” said Dr Thorrold.
Farmers interested in learning more about improving their environmental performance and profitability can find out more at dairynz.co.nz/stepchange
Case studies: See the Greenhouse Gas Partnership Farms’ case studies on the DairyNZ website at dairynz.co.nz/GHGfarms. The case studies detail options for farms to reduce both nitrogen loss and greenhouse gas emissions, while maintaining or increasing profitability in some cases.
A snapshot of two Partnership Farms case studies
Two options were modelled in the Partnership Farms research for Flemington Farm near Ashburton. The farm is owned by Climate Change Ambassador Phill Everest and his wife Jos, and run with their son Paul Everest. The farm’s milking platform is 221 hectares of flat terrain, milking 750 cows.
The first option modelled focused on reducing nitrogen fertiliser use and cropping area, and reducing replacement rate of young stock, while maintaining production. This resulted in reduced nitrogen loss and emissions, and a slight increase in profitability.
The second option builds on the first option and aims to reduce nitrogen loss by a further 12 percent by reducing nitrogen fertiliser and substituting pasture grown with low nitrogen supplements. This results in further reductions in nitrogen loss and emissions but also decreased profitability.
Phill said the family use technologies and systems on-farm that improve efficiency, resource use and sustainability and are committed to continual improvement. They have already reduced their stocking rate 5 percent. “We care for the environment, but we need a balance between the social, economic and environmental aspects, said Phill.
Five options were modelled for the Moss family farm, Tokoroa Pastoral, in Waikato, owned by Climate Change Ambassador George Moss and his wife Sharon. The 70-hectare farm milks 175 cows.
The research found farms such as Tokoroa Pastoral, which are highly efficient, generally can only slightly reduce environmental losses without affecting profitability.
The modelling showed reducing replacement rate achieved a small reduction in greenhouse gases (GHG) and a small gain in profit, and looked to be the best opportunity. This option relies heavily on reducing the not-in-calf rate and finding an alternative use for additional grass grown on the support block.
The modelling on Tokoroa Pastoral also showed reducing imported supplement is the option most likely to reduce GHG, but this tended to reduce profitability. When combined with a reduction in nitrogen fertiliser use, it made the largest reductions in GHG emissions, with a small drop in profitability.
George said he had taken steps to reduce emissions, including fast forwarding his genetics with sexed semen, using urease inhibitors and managing down his nitrogen surplus.
“After farming in Tokoroa for around 30 years, I am now planning ahead for changes expected in the next 30 years,” he said. “As a society, we know greenhouse gases need to reduce from basically all sources – and it will take each and every one of us.”
- A farmer’s replacement rate is the number of heifers coming into the herd, replacing cows moving out of the herd for various reasons, such as age.
- Urease inhibitors prevent losses of nitrogen from fertiliser when it is applied to paddocks.
- DairyNZ Partnership Farms research frequently asked questions.