Dannevirke dairy farmer Blair Castles is a farmer on a mission. He says when he found out DairyNZ was suggesting using plantain to reduce nitrogen (N) leaching, he was keen to get on board. He’s just one of several farmers in the area who are tackling the issue head-on and sharing their findings with other farmers, thanks to DairyNZ’s newly established Tararua Plantain Project.

“I like what DairyNZ is trying to achieve and I’m keen to show other farmers what plantain is like in a sward,” says Blair. “To reach the Horizons Regional Council targets, we have to reduce N leaching on our farm by eight to nine kilograms per hectare (kg/ha). All of us in the region need to get on board and do our best to be compliant.”

Led by DairyNZ, the Tararua Plantain Project is helping unconsented farmers keep on top of nitrogen leaching. (Left to right: DairyNZ catchment engagement leader Adam Duker and local dairy farmers Mark Diamond, Blair Castles and Brad McNaughton.)

Why this project is important

In the upper Manawatu, a significant proportion of dairy farms are operating without consent for intensive farming activities. They’re faced with reducing N leaching by an average of 60 percent to meet targets outlined in the Horizons Regional Council One Plan. It’s a massive challenge.

Turning over a new leaf: Tararua catchment farmers need to reduce N leaching by an average of 60 percent to meet regional council targets.

The Tararua Plantain Project sees a new approach by DairyNZ to fast-track development of science, through simultaneous research (locally and on research farms), recognising the size and urgency of the tasks ahead.

Through the project, DairyNZ scientists are working with unconsented farmers in the catchment. It’s one of three catchment-specific projects helping farmers reduce their farm’s environmental footprint. Paddock-scale research has begun on six farms and the findings will be shared with other farmers in the area.

DairyNZ catchment engagement leader Adam Duker had already been helping individual farmers in the area to complete their farm environment plans (FEPs are part of One Plan regional planning requirements). DairyNZ has also been working as an intermediary between farmers and Horizons to understand the catchment objectives and communicate these to farmers in practical terms so they can make on-farm changes.

“The low-cost production success of traditional ryegrass/clover in pasture is widely accepted,” says Adam, the project’s lead. “But I hope that once plantain’s effectiveness in reducing N leaching has been demonstrated by this project, farmers in the district will see the merit of including it in their swards.”

Early adopters: farmers in action

Tararua dairy farmers Blair Castles, Mark Diamond and Brad McNaughton are already using plantain in their pasture. As System 2 and System 3 farmers and members of the project’s monitoring group, they’re keen for others to learn from their results.

Adam Duker (second right) says the aim of the project is to help farmers make plantain work in their systems to significantly reduce N loss, while maintaining farm profit.

Blair Castles

Blair has been using plantain, along with chicory, for about six years. He’s looking at taking out chicory and lifting the rate of plantain. At present, chicory is 10 percent of his sward; plantain’s about the same.

“It wasn’t difficult to establish but it’s been very effective. We wanted to use more herbs in our ‘fruit salad’ pasture of ryegrass and clovers. We’ve achieved this and the cows like it. Depending on the trials, we could increase plantain in the future. We’ll do anything we can to be compliant with the council regulations.”

Blair plants plantain in autumn, after the summer turnip crop has been lifted. He has a 15 percent regrassing programme underway, so it’s early days in terms of results with plantain.

“When I first started using it, I had some concerns around bloat on plantain, which doesn’t happen with chicory. We had to monitor it, but so far we haven’t had any problems. As a precautionary measure we add bloat oil to the drinking water, which covers the clover as well, and this seems to be working well.”

He plants kale in winter and will also add fodder beet to the mix this year. “We used to grow swedes for our main winter crop, but this year we’re changing to fodder beet on the runoffs and a bit on the milking platform as well.” Blair tries to keep his use of urea low: about four tonnes per year on the 100ha milking platform. He says this seems to be an effective ratio, so it’s not necessary to pump more on.

“Farmers in the area are being proactive and we have council support, so working with the scientists has to be a good thing – I’m all for it. The One Plan limit-setting process can be quite overwhelming for farmers, but when you’ve got DairyNZ scientists doing this research it’s not so daunting. I’m very happy to help and be part of it.”

Brad McNaughton

Blair's neighbour Brad McNaughton has already done a few farm trials of his own and is including chicory and plantain in his pastures. About four years ago he started using ‘Rocket Fuel’ – a mix of plantain and chicory with white and red clovers.

Reducing N leaching in streams (like the Raparapawai Stream on Brad McNaughton's property) will contribute to improving water quality across the catchment.

Levels of algae and insect life are two elements to consider when assessing the health of streams, rivers, lakes and other waterways.

“Plantain did well, so we’re now including it in our regular regrassing programme,” says Brad. “We’re regrassing about 12 percent of the pasture a year, incorporating two kilograms (kg) plantain with 25kg ryegrass and 4kg clover.

“Plantain has deep roots and is drought-tolerant, which is good for us because we’re not irrigated and it can get very dry here in the summer. I’m waiting to see how we go in autumn and whether the cows find plantain less palatable.”

Brad says the monitoring group meets every three months, or before drilling, to gauge what everyone’s doing and share information about the trial.

“Next season we'll sow in spring. I find you have to be exact with sowing plantain. We spray out with a herbicide after the turnips are lifted and direct drill the seed.

“I learned farming through DairyNZ discussion groups and talking to others but it will be a big step to plant 30 percent plantain. To some extent, it will come down to cost. Herbs are just another species in the paddock but if the trials are successful, we’ll aim to gradually increase plantain in our pastures until we reach 30 percent.”

Mark Diamond

Mark has been using plantain for three years. In a 10ha trial, he’s using about 2kg plantain/ha as part of a mixed sward with ryegrass and clover, which he sows after the summer turnip crop has been lifted. “Plantain is easy to grow and is part of our ongoing regrassing plan. It’s easier to manage than chicory and the cows love it.”

Mark says farmers know they must make changes but, because every property is different, there’s no ‘one size fits all’ solution. “We all live in houses of different shapes and sizes with different coloured roofs. Farms are much the same. Brad’s property is completely different to mine, even
though we share a boundary fence.

“It’s definitely a hard one. Some farms have higher rainfall than others, and there are different options available to help reduce leaching, like off-paddock infrastructure and changes to farm systems – but these all come at a cost.”

Mark is also trying a few other things, like using gibberellic acid and liquid urea, to strategically-reduce N losses and increase pasture growth at times when growth rates are typically low.

“The project has just started and I think there is merit in it, but we’ll have more information in 12 months’ time. The scientists are going to measure everything and tell us if plantain has made a difference to production and the bottom line. I’m hoping it’s a ‘goer’.”

The Tararua Plantain Project provides a case study which could see dairy farmers in other parts of the country adopt the use of plantain to reduce N leaching.

Where to from here?

“Plantain is an excellent low-cost opportunity to make a positive impact on the One Plan targets at farm and catchment levels,” says Adam Duker. “This project will help farmers to make plantain work in their systems, with the aim to significantly reduce N loss while maintaining farm profit. We have an ambitious goal to have 95 percent of unconsented farmers in the district with 30 percent or more plantain in their cows’ diets by 2025.

“Water quality monitoring and modelling will provide direct feedback to famers and the local community on the potential and actual improvements they’re making,” says Adam. “The project will serve as a case study for rapid adoption of new technology and a blueprint for possible adoption of plantain in other parts of New Zealand.”

Project background and support

DairyNZ catchment engagement leader Adam Duker, working with Horizons Regional Council, Massey University, agronomists and a six-strong project team, has developed the Tararua Plantain Project (based on previous research – see below) to help unconsented farmers. The project has outlined a seven-year plan to achieve adoption of plantain on 125 dairy farms, with the objectives to increase farm business and community resilience, and quantified gains in water quality. Levy funding ($638,500 for the 2018/19 season) covers the project’s establishment phase.

Massey University

Professor Peter Kemp and a team from Massey University's School of Agriculture and Environment are carrying out research at a university farm, measuring N leaching from plantain pastures compared with ryegrass pastures. They're supporting the project farmers by sharing the results of this research. In turn, Tararua farmers are contributing to the Massey research by evaluating ways to best integrate plantain into their farm systems.

Horizons Regional Council

Dr Nic Peet, Horizons strategy and regulation manager, says the project’s success will help drive water quality improvement in the Manawatu River and help farms meet regulatory requirements to reduce N.

“Without tools like the use of plantain, farmers in much of the Tararua are unlikely to be able to meet the One Plan N-leaching targets and remain viable. The plantain project is important and has the potential to make a significant difference – economically and environmentally.”

Previous and ongoing research – FRNL programme

The Tararua Plantain Project capitalises on research findings from the DairyNZ-led Forages for Reduced Nitrate Leaching (FRNL) programme. FRNL established that New Zealand-bred plantain cultivars reduce soil N concentration under cows’ urine patches. This allows plants to take up a greater proportion of N, reducing N leaching (estimated to be between 5 and 30 percent, depending on soil type and the proportion of plantain in the cows’ diet).

Words: Christine Hartley  Photos: Brad Hanson

For further information check out dairynz.co.nz/tararua and dairynz.co.nz/plantain

Farmers in the region can also contact Adam Duker, email adam.duker@dairynz.co.nz

This article was originally published in Inside Dairy December 2018