Farmers lead the way to better lake water quality

Project Rerewhakaaitu aims to develop whole farm nutrient management plans in order to decrease nitrogen and phosphorus losses into the lake.

In 2001, Project Rerewhakaaitu was initiated to improve water quality in the only Rotorua lake where dairy farming is the main activity on surrounding land.

A decade later, the project is now in
its third phase, aiming to develop
whole farm nutrient management
plans in order to decrease nitrogen and
phosphorus losses into the lake.

The first two phases of the project built up an understanding of how to minimise nutrient losses on these farms, and the third phase is now implementing this knowledge on farms.

Rather than taking a top-down approach, this project is unique in being farmerled,
with support from AgResearch and the Bay of Plenty Regional Council.

Ian Power and Bob Longhurst, Scientists at AgResearch’s Environmental Footprinting Centre (EFC), say that the farmers “are a really enthusiastic bunch of people and they are keen to do the right thing so that water quality improves.”

The EFC helps dairy, sheep, beef, deer, goat, arable and horticultural farmers,
businesses and regional councils understand nutrient flows and losses. The EFC also provides expert guidance on making the best use of nutrients to give
high production with low emissions.

Project Rerewhakaaitu has so far seen 27 dairy farms use OVERSEER® Nutrient
Budgets to develop farm-level nutrient budgets and determine what mitigations
could be undertaken to improve nutrient use efficiency and reduce nutrient
losses. The farmers have also completed “Enviro Walks,” which identified “hot
spots” where nutrient or sediment loss can impact water quality on farms.

Farmers will implement their own nutrient management plans where
possible. From these results, an overall catchment management plan will
then be developed, which will ensure the long-term health of the lake.

The Project has been funded by the MAF Sustainable Farming Fund, the Bay
of Plenty Regional Council, DairyNZ, FertResearch and AgResearch.