Plantain Projects

DairyNZ’s Plantain Potency and Practice Programme is testing the effectiveness of Ecotain environmental plantain for reducing N leaching from pasture and its impact on farm profit. Tararua dairy farmers are trialling pastures containing Ecotain plantain to reduce N leaching and help meet regulatory requirements. 

Use of the herb Plantain has the potential to reduce nitrate leaching from dairy pastures through a combination of animal and soil effects. Across New Zealand, various small plot trials, farmlet trials, and partner farm studies are taking place.  

They aim to develop plantain management guidelines and to understand its impact on soil carbon and nitrogen cycling. These trials also evaluate nitrate leaching losses, milk production from plantain-rich diets, and the health and welfare of cows. Some research focuses on plantain's persistence and yield under different grazing and climatic conditions.  

Plot trials at Massey’s No.4 dairy farm.  

Experimental rye/clover paddocks have been sown with 0%, 30%, 50% and 70% of Ecotain plantain (a variant selected for its demonstrated effectiveness). Cattle graze either the standard ryegrass/clover sward or one of the experimental paddocks systematically throughout the season.  

Each paddock has its own drainage system from which water samples are collected and tested for nitrate. Other data collected include the composition of milk, urine, faeces and blood from each cow; the species composition of each paddock, its DM yield and quality.  

Three years of measurements indicate that the plantain pastures have reduced nitrate leaching by 20 to 50% compared with the standard rye/clover pastures, with no impact on production. A similar trial at Lincoln indicated a nitrate reduction of around 20%. 

Milk testing by Fonterra has shown that there is no negative impact of plantain on milk quality or processing attributes.  

The Plantain programme now involves 25 farms nationwide to develop regional management strategies for incorporating plantain into farm systems and compare the cost with other N-leaching mitigation options. Modelling conducted for the partner farms shows that plantain is consistently one of the cheapest ways of reducing N leaching. 

Plantain also has potential to reduce on-farm greenhouse gas (GHG) emissions. Trials conducted through the Agricultural Greenhouse Gas Research Centre have shown that a 30% Ecotain sward can reduce nitrous oxide emissions from urine patches by up to 50%, but other studies have shown variable results possibly due to soil or climatic factors, and further work is needed to understand this.  

Plantain management 

Plantain generally outperforms ryegrass in summer and when it is dominant more frequent grazing based on forage height is advisable. Plantain does not compete as well in winter and is susceptible to treading. Also, it is not as persistent as ryegrass, and lasts in pastures for only 2-3 years. Farmers are managing this by incorporating plantain into all new pastures, and broadcasting seed with fertiliser across the farm every 1-3 years. Some farmers are also trying undersowing or using plantain as a crop.  

Tararua Plantain Project  

Tararua dairy farms are some of the most efficient and low-intensive in the country. However, regional council regulations require many dairy farms to reduce nitrogen leaching substantially. To meet this massive challenge DairyNZ and partner organisations* have been working with farmers in the catchment to help them establish and learn to maintain Ecotain plantain as an environmental forage. 101 farmers in the region now use plantain. 

Ben Allomes is one of these farmers. His 290ha dairy unit runs a herd of 640 cows plus replacements. He says he knew he needed to make management changes to meet environmental targets and remain profitable.  He wanted to be “ahead of the game” and ensure that nitrogen leaching could be reduced successfully in the catchment. Research had identified plantain as a means of reducing nitrate leaching and so he became a partner farmer in the Tararua programme.  

“Different farmers were trialling it in different ways – some just as part of their pasture sward, others as a crop, and some had areas of their farm having only plantain”, he says.   

Ben has trialled several ways to incorporate plantain into his farm system, including as part of a crop with and without clover, sowing into new pastures, undersowing into existing pastures, and broadcasting.  

Pasture growth measurements as part of the programme showed that his plantain crops and pastures grew more dry matter than the ryegrass/clover pasture for most of the year. This result is typical of what has been achieved in the Tararua District, with plantain pastures growing on average 12% more. 

Ben says he is still working on the best way to incorporate plantain into his system. While the pure plantain crop grew a lot more, when oversown with ryegrass after a couple of years he found weeds were a problem. He is now moving back to using plantain in mixed pastures. 

He says that plantain is slow to establish in a sward but once it starts to grow it “goes berserk”. The key, as with any crop, is to do it properly and not cut corners. 

“We need to choose paddocks correctly, prepare them properly, manage the weeds and it will be successful. At one time we all thought that plantain would last a long time in pasture but at this stage it’s lasting only a couple of years, so we must take that into account.” 

Ben says in winter plantain may become less palatable to stock but in summer and autumn it really comes into its own and outperforms other species. In trials he found that his rye/clover pasture grew 12.5 tonnes DM/year, plantain crops grew 15 tonnes, and the plantain/pasture mix grew 19 tonnes. “That’s an order of magnitude better, and it’s worth a few complications to get that extra feed,” he says. 

Ben Allomes was a DairyNZ farmer-elected director from 2011 to 2019. Over the past 15 years he was also involved in the Agricultural Health and Safety Council, the DairyNZ Retention and Recruitment Group, the Rural Leadership Development Steering Committee, and the NZ Ag Safety Forum, among others. He was winner of the MPI Best Employer Awards in 2019. 

*The Tararua Plantain Project is led by DairyNZ, with partners Agricom, MPI, Fonterra and Nestlé. Delivery partners include AgResearch, Horizons and Massey University. 

DairyNZ leads the Plantain Potency & Practice Programme with co-funding from MPI, through the Sustainable Food and Fibre Futures initiative, as well as commercial partners Fonterra and PGG Wrightson Seeds.   

https://www.dairynz.co.nz/research/science-projects/plantain-potency-and-practice/