Risk index tool for on-farm nutrient management

The Risk Index Tool is a web-based on-farm nutrient management tool that assesses the risk of nitrogen loss and suggests practical actions that could reduce the risk. It was developed following the review of the Overseer nutrient management model and the Government response to the findings of the Overseer peer review report.

The RIT could help inform Freshwater farm plans (FWFPs) or council resource consent processing but its use is not required under legislation.

Councils and users will need to interpret the risk scores alongside other information to determine what they mean in a specific catchment.

See Government response to the findings of the Overseer peer review report.

Phase one of the RIT will provide:

• a risk score for nitrogen loss from farms and plantation forestry, based on environment characteristics, management practices and mitigations
• a risk score at farm and block scale
• a heatmap that shows hotspot areas of nitrogen loss risk.

N.B.: The RIT will not provide a kg of nitrogen number.

This will enable land managers to determine how land and practice management decisions impact nitrogen-loss risk. Areas of higher nitrogen-loss risk may need more work to improve freshwater outcomes.

View the slidedeck for an overview of how the RIT works.

A Technical Working Group of scientists and modellers provided technical and scientific oversight, guidance, advice, and leadership in the development of the Risk Index Tool. The Group consists of:

• Professor Richard McDowell – Lincoln University
• Dr Valerie Snow – AgResearch Ltd
• Dr Bethanna Jackson (late) – BEEA Ltd; Victoria University of Wellington
• Reina Tamepo – Scion Ltd

The Group developed technical documentation on the design and function of the RIT. These documents have undergone an independent peer-review.

Science and modelling experts from the Ministry for the Environment and the Ministry for Primary Industries have supported the group throughout the process.

Read the contaminant loss risk index tool technical document.

A nominated group of regional councils were involved in the RIT development.  This group consisted of representatives from:

• Environment Canterbury
• Greater Wellington Regional Council
• Hawke’s Bay Regional Council
• Southland Regional Council
• Waikato Regional Council

The Reference Group ensured that the RIT was developed to meet council needs, with some members also involved in the RIT’s user acceptance testing.

Draft implementation guidance for councils has been published with more guidance due before the tool’s release.

Read the draft implementation guide.

To ensure you receive all future news and updates on the RIT, please email: riskindextool@mfe.govt.nz