Benefits of plantain in pasture clear after four-year trial
A research programme led by DairyNZ has shown that adding Ecotain® plantain to dairy pastures can substantially cut nitrogen losses to freshwater, while keeping milk production and farm profitability steady.
The findings come from the Plantain Potency and Practice (PPP) Programme, which is a research initiative funded by the Ministry for Primary Industries, DairyNZ, PGG Wrightson Seeds and Fonterra.
A four-year farmlet trial at Lincoln University Research Dairy Farm found annual nitrate leaching dropped by an average of 33 per cent in perennial ryegrass – white clover pastures containing an average of 17 per cent plantain dry matter, compared with pastures without plantain.
The results back up findings from the programme’s grazing trial at Massey University and the aligned Low N Farmlet Trial, also at Lincoln.
DairyNZ Senior Project Manager Kate Fransen says milk production remained consistent across both treatments, with herbage production and silage use also similar.
“The findings demonstrate that plantain can deliver environmental benefits without compromising farm performance,” says Fransen.
The nitrate leaching reductions at Lincoln are more than double those predicted by current models, which only account for plantain reducing urinary nitrogen.
"The high water content of plantain dilutes the concentration of cow urine, and the nutritional makeup of plantain also causes more nitrogen to be diverted to faeces and milk, and less into urine," Fransen adds.
The findings demonstrate that plantain can deliver environmental benefits without compromising farm performance.
"We are now gaining a better understanding of the effects of plantain on drainage and nitrogen cycling in soil which result in additional reductions in nitrogen leaching."
One of the most significant findings was that relatively low levels of plantain still delivered substantial results – with reductions holding steady over four years despite plantain content plateauing to 10-15 per cent in the final years.
Plantain content in pastures naturally declines over time, so farmers need to periodically reseed it to maintain these benefits. Partner farmers have held 10-15 per cent plantain content by including Ecotain® in new pasture mixes and broadcasting seed each year, at an estimated $46 per hectare a year.
The benefits of plantain for reducing nitrogen leaching are already recognised in regional frameworks in Canterbury, Southland, Waikato, Bay of Plenty and Horizons. Research from New Zealand and Ireland also suggests plantain may help reduce methane and nitrous oxide emissions, with further work underway.
"Farmers are looking for options that improve environmental outcomes while supporting productive and profitable farm businesses," says Fransen. "The evidence continues to show that plantain can be an important part of that toolbox."
For more information, read the DairyNZ media release here.
You can find more about the programme on the DairyNZ website: Plantain Potency and Practice Programme - DairyNZ | DairyNZ.