Overseer report: Govt promises work on improving tools to manage nutrient losses from farms

Federated Farmers says the foundations of New Zealand’s farm environment management system have been rocked to the core by the release of today’s report into the effectiveness of farm nutrient modelling system Overseer.

The report by an independent Science Advisory Panel has identified shortcomings with the current version of nutrient modelling software Overseer and concluded that it had no confidence in Overseer’s ability to estimate nitrogen losses from farms in its current form.

The feds have been fighting against the use of Overseer by local councils to define regulations for nutrient management on farm for more than a decade.

Their complaint has been Overseer’s lack of accuracy.

While the farm leaders were expressing their dismay, Environment Minister David Parker and Agriculture Minister Damien O’Connor were promising the Government will help develop improved tools to manage and estimate total on-farm nutrient loss.

The Ministers welcomed the government-appointed Panel’s report and said it will help develop improved tools for farmers and regulators to meet future Essential Freshwater planning requirements.

“Despite its shortcomings Overseer has been a useful tool to build awareness and influence practices to manage nutrient loss at the farm and catchment level,” David Parker said.

“There is a robust body of independently peer-reviewed knowledge on nitrogen mitigation options that sits alongside Overseer.

“Farmers have used Overseer, alongside advice, to improve practices and freshwater outcomes.

“We encourage farmers to continue their vital efforts to reduce nutrient losses.”

The Ministers say they recognise the urgency of the work, given the 2024 deadline for Regional Councils to develop RMA plans under the Essential Freshwater reform package.

“Our farmers and growers have put in a significant amount of work and investment over many years to boost environmental outcomes on-farm,” Damien O’Connor said.

“The Government will seek to ensure improved tools for estimating nutrient loss are transparent, accurate and effective.”

“Options to be considered include developing a risk-based index, developing a next-generation Overseer to address the panel’s concerns, greater use of controls on practices to manage nitrogen leaching, and potentially longer-term developing a new approach altogether.”

David Parker said it was vital farmers and councils had some certainty over the next year. Councils will continue to implement their plans and the freshwater reforms.

Damien O’Connor said it was essential that farmers and councils using Overseer have some certainty on how to proceed.

For this reason, the Government will support work on a next generation Overseer.”

Regional councils will continue to administer consents to manage freshwater at the farm level although there may need to be adjustments in the approach in some cases.

David Parker said:

“We’ve spoken with Councils, and they can proceed with developing plans on the basis that nutrient loss estimation, and risk assessment tools will be available for the preparation of those new plans by the end of 2024.” 

Damien O’Connor said:

“We need to build on the progress that farmers have already made.”

Over the coming months, officials will develop best practice guidance for models used in environmental regulation and these will feed into approaches and tools in the longer term.

“The Government supports the development of a next generation Overseer and other nutrient management tools. Having fit for purpose tools now will support our farmers to deliver long-term environmental benefits across New Zealand,” Damien O’Connor said.

The mood at Federated Farmers was more bellicose.

“This report is scathing. It basically says Overseer should never have been used for anything other than general on-farm nutrient use management,” Federated Farmers environment spokesperson Chris Allen says.

Despite this, and the protestations of organisations like Feds for almost two decades, it is estimated more than 6000 farmers are strictly regulated by Overseer and another 5000 must do Farm Environment Plans with Overseer nutrient budgets.

This includes drystock, dairy, horticulture, arable and other farmers.

“All farmers and growers need answers so they have confidence in the way they continue to operate their farms, knowing what they do will have the outcomes they want,” Mr Allen said.

The Feds would like to invite the authors of this report to come and talk to us about the future for Overseer.

“Feds is keen to be involved. We are up for conversations with the owners of Overseer to help find a way forward for farmers.”

Overseer is used by councils all over New Zealand as the basis for granting consents, checking compliance and enforcement against farmers. It is even supposed to be used as a tool for estimating on-farm GHG emissions.

“We and the rest of the industry have been in hundreds of council and court hearings, spent millions of dollars, (of farmer and taxpayer money) and used thousands and thousands of hours pushing back against officials trying to squeeze Overseer into a space that this report says it could not go.”

The ministerial press statement includes background notes:

There are three main causes of water quality degradation – excessive sediment, microbial contaminants, and nutrients. These causes are addressed in different ways in Essential Freshwater and Overseer is a tool that is used for managing nutrient losses.  For many of New Zealand’s rivers, the main nutrient challenge is excessive nitrogen in its various forms.

Overseer is a NZ-developed software tool that models the nutrient flows on to and off farms and farm blocks. It aims to provide a quantitative description of farm nutrient dynamics for a range of farm system types. It combines data on farm management, topography, soil and climate.

Overseer and its predecessors have been used for 30 years by many New Zealand farmers to estimate nutrient budgets and understand how nutrients are cycled on-farm. Recently, it has been used by a number of Regional Councils as part of their plans and consents to manage nutrient loss to rivers and groundwater.

It can be used on dairy, sheep and beef, milking goats, deer, outdoor pigs, kiwifruit, viticulture and some vegetable and arable crops to estimate the impact of management practice change on the use or discharge of several nutrients.

The Overseer intellectual property is jointly owned by the Ministry of Primary Industries, the Fertiliser Association of NZ and AgResearch. The intellectual property is exclusively licensed to Overseer Ltd, which is owned by the Fertiliser Association of NZ and AgResearch.

The report is HERE. 

Sources:  Federated Farmers, the NZ Government

Author: Bob Edlin

Editor of AgScience Magazine and Editor of the AgScience Blog