Project highlights nutrient loss challenges for farmers

Project highlights nutrient loss challenges for farmers.

Work by farmers on a Hawke’s Bay project aiming to cut their nitrogen losses has provided valuable lessons and highlighted the challenges ahead.

The “Greening Tukituki” project that included two dairy farmers and two drystock farmers from the Tukituki catchment aimed to help them meet their nutrient loss obligations under the Hawkes Bay Regional Council (HBRC) plan change 6.

The project closes amid growing disquiet about the shortcomings in nutrient software system Overseer as a regulatory tool.

A recent report by Parliamentary Commissioner for the Environment Simon Upton found gaps and shortcomings in Overseer that undermine confidence in its suitability as a regulatory tool to be used on farmers.

The Hawke’s Bay plan change requires farmers to match their nitrogen losses to their Land Use Capability (LUC) classification, spanning eight different classes based on the property’s physical characteristics and attributes.

The results from two farms have highlighted the successes and challenges that face many farmers throughout the catchment, and throughout New Zealand as every region starts to grapple with plan changes managing nutrient losses.

Takapau feedlot farmer Rob Foley found the project invaluable in presenting him with some options when the data gathered during it identified the 1100 dairy cows he grazed over winter as being a key source of nitrogen losses.

His options were to either undergo expensive bore testing to determine just how much nitrogen was being leached from cow urine, or consider a lower nitrogen loss type of farming.

He opted for the latter, dropping the cows for half the number of bulls, reducing his LUC loss from 41kg nitrogen a hectare a year to 36kg.

“While the cash flow is definitely reduced by not having the dairy grazers, financially it is still profitable running the bulls instead,” he says.

Other areas being examined through the project have included losses from winter wheat and examining different grass species including plantain to absorb nitrogen.

“For us the project was definitely worthwhile. It has been good to be part of a project focused on how to become more compliant, and to also demonstrate to council just how hard it is to not only do these things, but to still make a profit.”

Ashley Clinton dairy farmer Andy Hunt has not had all his nitrogen issues solved by the project, but it has lifted the hood on some of his options, and highlighted to the Regional Council team how challenging meeting nitrogen loss targets can be. Hawkes Bay Regional Councils was one of the supporters of the Tukituki project.

Significant time and energy has been invested into working out options for the 360-cow operation to get it within 30% of its LUC nitrogen leaching rate limit of 21kg of nitrogen a hectare a year. At present it is about 40% over its LUC allocation.

The Hunts accept there is no “silver bullet” solution to getting the farm within that limit, but one tool presenting itself has been to plant more plantain in the farm pasture mix. This has been shown to help reduce nitrogen losses.

“But the project has also highlighted that plantain is not included in the Overseer model, and until it is this possible tool is out of our hands to some extent,” says Hunt.

He was however encouraged by the regional council’s positive attitude to incorporating plantain into the farm system for nitrogen loss mitigation.

Another option presenting itself could be to also construct a compostable barn, but the $500,000 plus price tag means he needs more assurance from the regional council the operation will be compliant if he goes ahead with it. An alternative is to further reduce the stocking rate of the already low-stocked farm but this impacts on profitability and long-term viability.

“You could say the project has not solved our problems, but it has certainly raised the profile of them and has also highlighted these challenges to the council that we face to meet these standards.”

Photo caption: Hawke’s Bay farmer Andy Hunt and MyFarm consultant Rachel Baker.

Project manager and MyFarm agribusiness consultant Rachel Baker said there is considerable uncertainty around how farms in the catchment are going to meet the plan change standards.

“And this is from farms that at face value are picture perfect – well run, with healthy stock and owners who really care about the environment.

“Plantain looks like it could prove a game changer in helping reduce nitrogen losses, and that is supported by peer reviewed science. It’s something many farmers including Andy Hunt have also been sowing in their swards for a few years now.

“And in the case of Rob, he took some steps very quickly by stopping dairy cow grazing and replacing them with bulls, and immediately reducing the magnitude of nutrient loss. However this in turn presents a challenge for where dairy cows will be wintered in future.”

She said the project has also been instrumental in putting the practical realities of the council plan change in front of those that implement it, and had helped build greater understanding between council staff and farmers about the plan’s impact.

The Greening Tukituki project was sponsored by AGMARDT, Hawkes Bay Regional Council, Beef and Lamb New Zealand, Ballance Agri Nutrients, DairyNZ and ANZ. The full report can be viewed at www.myfarm.co.nz/tukituki

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