Plantain offers a practical way to reduce nitrate losses

Four years of research found plantain reduced nitrate losses without compromising milk production, giving farmers another option for balancing productivity and environmental goals.

Farmers are increasingly looking for practical tools that improve environmental outcomes without compromising the productivity of their businesses. New results from DairyNZ’s Plantain Potency and Practice programme suggest plantain may have an important role to play.

A four-year farmlet trial at Lincoln University Research Dairy Farm found pastures containing an average of 17% plantain dry matter reduced nitrate leaching by 33% compared with standard ryegrass-white clover pastures. Annual total nitrogen losses were also 17% lower.

Importantly, milk production, pasture growth and silage use remained similar between the two systems, according to DairyNZ. The research suggests environmental gains can be achieved without reducing farm productivity.
 

More impact than expected

One of the most significant findings was the size of the reduction. Current modelling tools such as Overseer largely account for the way plantain changes how cows process nitrogen, reducing the amount excreted in urine.

However, researchers now have evidence that plantain also influences soil nitrogen cycling and drainage processes, contributing to larger reductions than previously estimated.

The programme found nitrate leaching reductions were more than double those predicted by current modelling approaches. While further work is underway, the findings help improve understanding of how plantain functions within whole farm systems.

Lower plantain levels still delivered results

Another interesting outcome was that high levels of plantain weren’t required to see benefits.

Plantain content changed over the course of the trial, but researchers continued to record reductions in nitrate leaching even as plantain levels declined. That’s encouraging because it suggests meaningful gains can still be achieved without maintaining high levels of plantain across the farm at all times, addressing one of the common questions farmers have about mixed-species pastures.

Research from the programme’s partner farms suggests many have successfully maintained around 10-15% plantain content by including Ecotain® plantain in new pasture mixes and broadcasting seed across the whole farm annually.

A practical option for farmers

Alongside the research trials, DairyNZ has worked with more than 30 farmers in nitrogen-sensitive catchments to better understand how plantain fits within commercial farming systems.

The programme suggests achieving similar reductions in nitrogen leaching without plantain could require more costly changes to nitrogen fertiliser use, imported feed, stocking rates or infrastructure investment.

Plantain won’t be the right fit for every farm, but the results continue to build evidence that it can be a useful tool for farmers seeking to improve environmental outcomes while maintaining productive and profitable businesses.

Research is also underway to better understand whether plantain can help reduce methane and nitrous oxide emissions, adding to the potential benefits already being explored by the programme.

For more information about the Plantain Potency and Practice programme, visit the DairyNZ website or talk with your local Farm Source TSR.