Solutions to reduce emissions footprint

DairyNZ’s 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,” DairyNZ strategy and investment leader Dr Bruce Thorrold says.

For some farms, the research identified options that offered lower footprint and higher profit. However, for already highly efficient farms environmental footprint gains tended to come at a cost to profitability.

“It is more challenging for farms that are already efficient,” concedes Thorrold. “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 currently working through a process of helping farmers understand their emissions profile numbers, identify options and implement solutions.

The Partnership Farms research project highlights that to reduce footprint, all farms had to decrease total feed eaten and nitrogen surplus: findings also underline the need for ongoing research into technology to reduce footprint without lowering feed.

Thorrold says these technologies are necessary for dairy farmers to achieve the challenging Climate Change Commission recommendations. He adds that 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 to support dairy farmers and the wider sector to address on-farm methane and nitrogen emissions long-term. Six farms in Waikato, Southland and Canterbury were involved in the research.

The research has found a strong understanding of the farm, its people and arm system is important at the beginning. The process involved a Whole Farm Assessment and modelling in Overseer and Farmax.

Thorrold says 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,” he explains.

“It’s about doing the right thing as a sector and consumers are also increasingly demanding sustainable products.”

DairyNZ’s next step is to work more with farmers to start exploring their own system adaptions through its ‘Step Change’ project. This is designed to help farmers understand the options best suited to their farm and how to improve profitability, 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,” Thorrold says.

Case Studies

Flemington Farm

Two options were modelled in the Partnership Farms research at Flemington Farm, near Ashburton.

The farm is owned by climate change ambassador Phill Everest and his wife Jos and run with their son Paul. 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, also reducing replacement rate of young stock, while maintaining production. This resulted in reduced nitrogen loss and emissions, and a sligh increase in profitability.

The second option buildson the first option and aims toreduce nitrogen loss by a further12% by reducing nitrogen fertiliserand substituting pasture grown with low nitrogen supplements.

This resulted in further reductions in nitrogen loss and emissions, but also decreased profitability. Phill Everest 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%. “We care for the environment, but we need a balance between the social, economicand environmental aspects,” he says.

Tokoroa Pastoral

Five options were modelled for the Moss family farm, Tokoroa Pastoral, in Waikato.

The property is 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 that reducing replacement rate achieved a small drop in greenhouse gases (GHG) and a small gain in profit. This 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 cutting imported supplements is the option most likely to reduce GHG. However, this tended to reduce profitability.

When this was combined with a reduction in nitrogen fertiliser use, it made the largest decrease in GHG emissions, with a small drop in profitability.

Moss says he has 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 says. "As a society, we know greenhouse gases need to reduce from basically all sources - and it will take each and every one of us to do it."