Pastoral farming contributes significantly to the New Zealand economy but can have adverse environmental affects. Nitrogen and phosphorus leaching into water ways are known to affect the health of aquatic wildlife and can have health implications for humans. Nutrient leaching can be reduced by mitigation. Understanding the effectiveness and cost of mitigation is critical to informed farmer and policy maker responses to these challenges.
In this paper we combine existing research with expert knowledge to construct a picture of what nitrogen and phosphorus mitigation is likely to be possible, at a national level, over the next eight years. We distinguish between mitigation that is probable (likely to be implemented given current trends), and mitigation that is possible (while technologically feasible, is unlikely to be implemented given current trends).