Thursday, August 11, 2022

Overseer faces evolution over revolution

Overseer chief executive Jill Gower says changes to the software will be incremental, rather than a complete makeover of the system.

Farmers and consultants concerned that a review of Overseer may see the software dumped for a new system have been assured by the new chief executive that the longstanding nutrient programme will not be wiped for a replacement.

Jill Gower spent three years as Overseer company secretary before assuming the interim CEO role in February and is now in the permanent role. 

With about a month’s worth of review work still to complete, Gower said if a new modelling system is required it will be invented, but she sees no fundamental change in the way Overseer’s proposed reiteration will work.

“Overseer is a particular type of model chosen for a reason, and one both farmers and scientists can use. There is no blank slate we are starting from,” said Gower.

Overseer’s  review comes after a stinging report from a scientific panel on the software almost a year ago.

Criticisms of Overseer that prompted the review included its lack of real-time monitoring, use of average climate data, and problems monitoring nitrogen surface flows.

Gower said when considering the real-time criticism, it would not be unreasonable for that to prompt the development of another tool more suited to such an application, one that could be used in parallel with Overseer.

She pointed to work being done by the Ministry for the Environment in this area that may meet that need.

A recurring criticism of Overseer from some scientists has been a need for greater peer review of its workings, with some claiming the software is akin to a “black box” few are privy to.

But Gower said the opportunity to review Overseer’s workings is adequate, and even more so with the development of “Overseer Sci”, a programme developed to analyse Overseer’s model workings, and available to scientists to use.

Meantime during the review process the company has tapped all the key research providers in the country for input on the model. This has included reviewing each area of criticism in last year’s report. 

The use of average climate data is now being considered against a daily data-averaging approach. Hydrology concerns on how water transports nutrients are being addressed, and nitrogen leaching estimates are being reviewed.

Some scientists, including Sir Peter Gluckman, have criticised Overseer’s ownership model – it is shared between MPI, the Fertiliser Association and AgResearch – saying it needed to be aligned with a trust or not-for-profit structure.

But Gower said Overseer’s constitution clearly lays out its base intentions, and commercial gain is not the top priority among these.

“The owners work collaboratively with a shared purpose, in a way very much how a not-for-profit would also operate,” she said.

Overseer subscribers have borne a hike in annual subscription rates over the past 12 months that has almost doubled the cost to about $680 a year, an increase Gower reassured them is not going to be repeated. The current rate, she said, represents realistic value given the software’s complexity.

Despite the uncertainty the review brought with it, Gower said subscription growth has continued, with the year ending up as one of the best ever.

She is unsure about the approach councils will take in using Overseer in the future when setting nutrient regulations. At this point there are several regional councils around New Zealand eyeing the review process, having employed Overseer to help set nutrient limits for farming.

She said she takes comfort in the fact that councils have continued to work with Overseer as the review progresses,  but acknowledged there could be potential for another model to evolve for council use. 

“We have always talked about there being a suite of tools, it does not have to be a binary argument,” said Gower.

Southland Regional Council is one of the few that has not used Overseer in its proposed land and water plan to identify specific targets, rather using Overseer to chart a general direction of travel, something many farm consultants and farmers would prefer to see.

“We see Overseer to be used as a source of information to help establish a farm environment plan, but more like Xero than like the IRD,” said Gower.

The recommended changes to Overseer will be passed to a government technical advisory group for assessment later this year.

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