Latest plantain trial shows role in reducing nitrogen leaching

DairyNZ

DairyNZ’s Plantain Programme continues to show strong results, with new data confirming that modest levels of plantain in pastures reduce nitrogen leaching.

This gives farmers a practical, science-backed tool to meet environmental targets.
Three years of Lincoln University trials show a 26% reduction in nitrate leaching with an average 17% Ecotain plantain in pasture. Massey’s four-year trial shows a similar 26% reduction with an average 25% plantain. Monitoring on four mid-Canterbury farms demonstrates that 10–15% plantain across entire farms is achievable by including plantain in seed mixes during pasture renewal and by broadcasting seed with fertiliser. New swards can reach 20–40% plantain within 1–2 years of establishment.

Programme lead Kate Fransen highlights plantain as a low-cost, practical option for farmers: nitrogen leaching is a major issue, but only modest plantain levels are needed for significant benefits. Research shows that 17% plantain across the farm is enough to make a sizeable difference, and that 10–20% is realistic for most farms. Final data collection at Lincoln is underway; Massey’s is complete.

The next phase focuses on adoption in nitrogen-sensitive catchments. Farmers nationwide are adapting the science.

In Rotorua, up to 20% plantain is being achieved by broadcasting seed with fertiliser, with 17 of 26 dairy farmers planning to use plantain to meet their 2032 nutrient targets. Modelling suggests a 5–7% higher profit for farmers using plantain compared to alternative strategies. Southland farmers are maintaining 8–10% plantain by including it in re-grassing mixes and trialling fertiliser broadcasting, potentially lifting profits by 7–9% per hectare at 10–20% plantain. Mid-Canterbury partner farms are successfully achieving 10–15% plantain in mixed swards.

Overseer estimates every 1% of plantain in pasture cuts nitrogen leaching by about 0.6%, largely by reducing N in urine patches. Research suggests further reductions through soil processes, with measured leaching reductions exceeding modelled estimates.

Understanding these soil processes is a key priority for the next three years so the full benefits can be reflected in Overseer.

Plantain is recognised as a mitigation option by regional councils across New Zealand. The Agritonic cultivar, marketed as Ecotain, is used in trials.

A new evaluation system is being developed to assess other cultivars and may extend to other species. The Plantain Potency Programme is a seven-year research initiative led by DairyNZ with support from MPI, PGG Wrightson Seeds Ltd, and Fonterra.