Plantain, a common weed, is being injected into pastures to help reduce nitrogen leaching into the district’s waterways.
The fibrous plant holds less nitrogen, meaning less passes through a cow’s system after they eat it. It also causes them to pass urine more frequently, resulting in less concentrated urine patches in a paddock.
Many farmers in the upper Manawatū River area are operating without consents, faced with reducing nitrate leaching by 60 per cent to meet targets in Horizons Regional Council’s One Plan.
Run by DairyNZ, the Tararua Plantain Project is tackling the problem head on, with several farmers getting on board and sharing their findings.
Dannevirke farmer Blair Castles has used plantain and chicory for six years on his 100-hectare block, which spans 5 kilometres of the Manawatū River.
He has considered scrapping chicory and lifting the rate of plantain in his «fruit salad» pasture of ryegrass and clovers.
Each year, Castles pulls 1250 kilograms of milk solids per hectare and, on small blocks like his, every square metre has to be profitable.
The industry often received a bad wrap for punishing the environment, but people didn’t see the investment going into modern-day farming practices, he said.
«It’s hard to say this is the silver bullet. You get labelled as the dirty dairy people and, to some extent, there are some muppets out there.
«Up here, with these smaller farms, it’s not so intensive, but we all get painted with the same brush.»
Castles was initially worried about plantain bloating his cows and added bloat oil to the drinking water as a precaution. «But we haven’t seen any yet.»
The project showed farmers were serious about keeping the country clean, he said.
«Everyone wants to take their kids down and throw a fishing line out or go for a swim.
«You’ve got to make a living off the land, but you don’t want to see the river getting dirty and everyone is on board with that now. We don’t own the river. It’s just water passing through.»
Dairy NZ catchment engagement leader Adam Duker has worked as an intermediary between farmers and Horizons.
Although the low-cost production of traditional ryegrass and clover was widely accepted, Duker hoped all farmers would see the merits of including plantain in their swards once this project showed it reduced nitrate leaching.