In a normal season, maize stubble wouldn’t be required as a feed on dairy farms.
The first part of the review will look at Overseer’s suitability as a decision-making and regulatory tool, and the panel is expected to report back on that by the end of the year.
Farmers have long voiced concerns that the software, originally promoted as a planning tool for them, was increasingly being eyed by regulatory bodies as a potential compliance tool.
Feds’ water and environment spokesman, Chris Allen, said the review was very timely and long overdue.
“We need to know what its strengths and weaknesses are, given that no-one really gets to look under the bonnet into how it really works.”
Allen said he was not knocking Overseer. It did a good job of benchmarking “what-if” scenarios but gave differing results with frequent updates and changing models.
He questioned whether it could come up with “a single number” for regulatory purposes.
“What sort of signal is it sending farmers or land users when the number you got five years ago has no relevance to the number you get today?”
Allen said a lot of data inputting had to be done with “workarounds” to get meaningful results.
“We would probably take a lot of convincing. We’d say it would be quite a few years away until it would be an appropriate thing to have as a regulatory tool,” he said.
“After all, water quality will not improve because of Overseer; it will improve because of practises on the ground.”
A joint announcement from the Ministries for the Environment and Primary Industries said the review was a major part of efforts to improve decision-making tools for use on-farm.
“The eight independent and internationally-recognised environmental specialists will look ‘under the bonnet’ of Overseer to critically assess its modelling capability and explore potential improvements for its use,” said Ministry for the Environment deputy secretary, water and climate change, Cheryl Barnes.
“The panel’s conclusions and assessments will be critical to New Zealand’s future approach to land management. We must be confident that Overseer is the right tool to drive sound land management decisions and improve freshwater quality.”
The panel is expected to meet first on March 30 and report back by the end of the year on the first part of the review – Nigel Malthus