A Dairy NZ led research project, in which Massey University is a partner, helping dairy farmers improve fresh water quality has just received a $8.98 million boost from the Government. The Massey contribution to the research has been underway for two years on Dairy Farm 4.
Over the next seven years the Plantain Potency and Practice programme will focus on proving plantain’s effectiveness at reducing nitrate leaching and nitrous oxide emissions, investigating regional effects, and protecting the supply chain. The programme will use Agricom’s Ecotain environmental plantain because it already has proven effectiveness, but a system for evaluating the environmental benefits of other plantain cultivars will be developed.
Plantain use is predicted to lead to flow-on benefits to national and regional economies. This is due to farmers spending less on other nitrate leaching solutions, therefore having more money to spend on goods and services. Plantain use is expected to save farmers more than $1 billion per decade.
The work aims to give farmers confidence to invest in growing plantain as an animal feed on their farms throughout New Zealand.
Plantain is a pasture herb bred from the well-known weed. When cows graze on plantain the concentration of nitrate in their urine is decreased. Urine patches are the main source of nitrate leaching so a lower nitrate concentration produces less leaching.
Massey University’s involvement will include the continuation of farm trials which are already underway and the expertise of Professor of Pasture Science Peter Kemp, Professor of Dairy Production Systems Danny Donaghy, Associate Professor of Soil Science David Horne and Research Officer Soledad Navarrete from the School of Agriculture and Environment.
On Massey’s Dairy Farm 4, seven hectares is covered in 20 experimental plots containing different levels of plantain ranging from zero per cent, 30 per cent, 50 per cent and 70 per cent mixed in with perennial ryegrass/white clover, the standard dairy pasture in New Zealand.
Professor Kemp says this is the most likely way farmers would use plantain mixed in with other pasture, “so our key objectives are to try to decrease nitrate leaching but also show farmers that the system works and that you can manage this kind of pasture and you get good milk production.
“Plantain has been reasonably widely used on sheep and beef farms for quite a while so there’s quite a reasonable amount of knowledge on where it grows around the country, but dairy farmers interest in it is driven by the effect it has on nitrate leaching and also that it decreases the greenhouse gas nitrous oxide emissions to some extent as well.”
He says it is a unique solution that for the first time a plant has been used to provide both a good livestock feed and an environmental improvement.
The farm trials are the key to showing nitrate leaching can be decreased at farm scale by plantain in pastures. Professor Kemp says these trials are a skillset at Massey, built up over the years but they have also had luck with the soil type that does not drain easily and therefore were able to put in their own drainage system and capture all water to analyse and compare the nitrate leaching that comes out of each paddock.
Other projects as part of the programme are also underway up and down the country including Fonterra looking at the effect plantain can have on milk quality and production.
Navarrete says from their previous research over the past two years they have seen little to no differences in milk production from cows grazing in the four pasture treatments during the 2019-2020 lactating season however Fonterra will investigate this further nationwide.
How plantain grows during the different seasons and on different soils will also be examined nationwide but Navarrete says currently plantain has similar growth rates compared to ryegrass when looking at their research from the past two years.
If proven successful, the partners from the programme will work with farmers nationwide using a co-development approach to help them adopt plantain onto their farms, measure outcomes and demonstrate success to other farmers.
Kemp says farmers have already been informed about their results gathered over the last two years and this has been presented to them through the Tararua Plantain Roll-out Project run by Dairy NZ. It aims to help farmers within that district who are faced with reducing nitrogen leaching by an average of 60 percent to meet targets outlined in the Horizons Regional Council One Plan. In turn for the support given by Massey University, Tararua farmers are contributing to their research by evaluating ways to best integrate plantain into their farm systems.
