A major initiative launched in the Tararua district seeks to reduce nitrate leaching on 135 dairy farms which can’t get consent for their operations. The hope is to achieve this with a single forage – plantain.
At least 100 people turned out for the launch held at the Woodville farm of DairyNZ director Ben Allomes. The day was organised by DairyNZ with input from Massey University, Horizons Regional Council (HRC) and Agricom.
N leaching is a huge problem for dairy farmers in the Tararua district since HRC introduced its controversial One Plan which requires all dairy farms to limit N loss. The problem in Tararua is high rainfall that makes dealing with leaching difficult. In the HRC region about 40% of the dairy farms are unconsented, most of them in the Tararua district.
Many attempts to solve the problem have been tried, but recent research at Massey and Lincoln universities, AgResearch and DairyNZ in Waikato and Canterbury has shown plantain offering unique possibilities to solve the problem on farms and at catchment level.
The research thus far has shown than plantain dilutes N in the urine, dilutes the N urine concentration in the paddock and secondary compounds in the plant that are thought to act as nitrification inhibitors and therefore more N is taken up by the plant and less is leached.
While there are still some unanswered scientific questions about why plantain is such an effective tool to mitigate N loss, a decision has been made to see if the results from the research plots can be successfully applied on a larger farm and catchment scale.
The ambitious target is to get 30% of plantain into the diet of cows in Tararua between January and May – vulnerable months in terms of N leaching on farms.
One of those leading this project is Adam Duker, DairyNZ’s catchment engagement leader for the lower North Island.
“We are committed to reducing the environmental footprint and specifically the nitrogen in Tararua district. We see plantain as a key mitigation option, certainly not the only one.
But we see plantain as something that in a research sense has been proven to reduce the N loss on farm and… preserve the profitable, pasture system NZ farming is renowned for.”
Duker says ultimately they want all dairy farmers in the Tararua district to look at their farming systems to implement efficiencies to reduce their footprint while retaining the economic viability of their business. He says they want farmers to consider integrating plantain into their farm system.
“We want to work with farmers in Tararua who are already adopting plantain and who are already seeing the productivity and environmental benefits. We are pulling in resources from all around the country to assist in this project and also use the local knowledge of farmers to get the best possible outcome. The aim is to hold meetings with farmers and work towards developing farm systems that are workable and practical,” he says.
Duker says they want to show the regional council that they are committed to finding a solution.
Saved his bacon
Plantain is not new, says Laura Keenan, Agricom. It’s been used for 20 years but mainly for its benefits as a high quality forage.
But she says with the intensification of farming, the other quality of plantain – as an answer to N leaching -- has added to its value to farmers. Now they’re keen to get into it.
Ben Allomes, on whose dairy farm the project was launched, has used plantain for five years, at first on rolling hill country but now as part of his normal farm system.
One reason for it was to raise the farm’s self-sufficiency in feed. He also feeds PKE and maize and grows oats and fodder beet.
Allomes says the system he’s developing isn’t perfect, but adding plantain has had benefits.
“The good thing about plantain was in the December dry we used it as a rotation crop. We split a 20ha paddock up like you might do with a chicory crop and the cows came on for two or three hours and were then taken off it.
“In January when we got all that rain we just turned it into a normal paddock so ever since then it’s been used as a paddock. It bought us a bit of time in December when PKE couldn’t arrive fast enough and when nothing else was growing; the turnips weren’t quite ready so it saved our bacon,” he says.