As farming intensified across New Zealand in the 1990s, a new and complex challenge emerged: how to protect waterways from nutrient runoff while maintaining productive farming systems.

Field trials, modelling and on-farm testing has helped reshape farming practices to safeguard water quality.

At this pivotal moment, scientists stepped in to help reshape farming practices for a more sustainable future, without compromising productivity. Their work centred on developing practical, science‑based solutions that could be readily adopted by farmers.

A major breakthrough came from research into nutrient losses associated with winter grazing. Scientists discovered large amounts of nitrogen were left exposed in soils during colder months, when plant uptake was low and the risk of leaching was high. This insight led to the development of practical catch‑crop systems – fast‑growing crops sown immediately after grazing to capture excess nutrients before they could reach waterways.

Extensive field trials, modelling, and on‑farm testing helped refine crop choices, sowing methods, and timing so they would fit within everyday commercial farming constraints. The results were compelling: nitrate losses to water were reduced by up to 60 percent, muddy runoff declined and farmers continued to produce valuable feed or grain.

By working closely with farmers and advisors to translate research into trusted, practical guidance, scientists helped embed these practices into routine farm management.