Written by Tony Leggett

Significant and immediate reductions in nitrogen and phosphorus loss to waterways are possible if dairy farmers put good management practices into action.

DairyNZ’s General Manager Sustainable Dairy Dr David Burger is leading the organisation’s efforts to help dairy farmers meet the new freshwater quality standards set by government.

He says Farm Environment Plans (FEP), developed by farmers with the help of their dairy company or trusted rural advisor, are a great first step to identify local risks and mitigation tactics.

One of the best examples of the power of FEPs is the Waikato Upper Karapiro catchment. Between 2013 and 2015, about 640 farm owners in the catchment voluntarily developed their own FEPs with the support of DairyNZ and rural professionals.

When qualified by modelling, an analysis of all the actions identified in these farm plans suggested, on average, reductions of 8% in nitrogen loss and 17% in phosphorus loss to waterways.

“These plans were voluntary not mandatory, and each farmer implemented the good management practices they agreed to in their plans,” David says.

“A lot of the actions undertaken by farmers in that catchment were about targeting the overland flow pathways, through critical source management and stock exclusion to manage run-off.

“Many actions also focused on effluent management. These included extending effluent block size and better managing nitrogen fertiliser.

“We know that farm plans are a fantastic tool for farmers because it helps them deal with local risks at an individual farm level,” he says.

By the end of March this year, more than 5,200 dairy farms had a FEP and momentum is building toward the goal of every dairy farm in New Zealand having a plan by the end of 2025.

“FEPs will certainly help but good management practices alone may not be enough to achieve the reductions required to meet regulatory water quality targets for every catchment in the country.

“For some farmers a system change may be required over the long term, but it’s not just about the number of cows. It’s much more than that.”

That’s where DairyNZ‘s Step Change project comes in. Launched in 2019, it aims to improve profitability while helping farmers make progress towards their environmental goals and meet changing regulations.

“Step Change is all about understanding your farming system, your key numbers and looking at your best options to reduce contaminants, while remaining profitable. We think there is a significant opportunity to create financial head room for our farmers to try and manage these bigger environmental challenges that are coming our way over the next generation.”

David says there are many catchments across the country that are not meeting the freshwater quality standards required in both rural and urban areas over the long term, so there is plenty of work to be done.

“For a lot of farms, an FEP may be all they need to make sure they can farm within the limits.

“For other locations, the farmers there will need more time to adjust and consider mitigation tactics such as introducing forages like plantain to reduce nitrogen (N) loss, or wintering systems that capture nutrients and reduce runoff to waterways. That is where our research comes in, to try and develop efficient ways to reduce our environmental footprint within the farm gate.”

Based on the success of plantain trial work in the Tararua region, four other catchments are testing it now.

“We’ve been working on barriers to adoption, but we believe we can get as much as a 30% reduction in N loss from plantain.”

Another good example of FEPs in action is the Aparima Community Environment Project in Southland where nearly 600 dairy and sheep-beef farmers are making huge strides to improve freshwater quality and reduce their environmental footprint in their region.

Aparima catchment landscape, Southland

A 2020 survey of project farms showed they achieve better environmental results when they have FEPs. The survey also highlighted that farmers with environment plans are more likely to implement a range of good farming practices.

Plans must include actions to reduce farm sediment and nutrient loss, outline how wintering rules will be implemented, and where to riparian plant and fence. The plans are reviewed annually.