The Overseer model received some unexpected attention in Parliament’s question time last week with Primary Industries Minister Nathan Guy challenged about the amount being invested into the model and ensuring its accuracy.
New Zealand First agriculture spokesman Richard Prosser challenged the model’s relatively low funding level and cited an AgResearch annual report that said it needed significant development to be fit for setting regional council nutrient limits.
“The Government is capable of raising $25 million for a referendum on whether or not we change the national flag, with no guaranteed result.
“That’s against $5m for a system that underlies not only three quarters of the economy but our entire environmental effort too.”
Guy acknowledged the model, critical for determining nutrient losses nationally through catchment plans, was receiving only $1.6m a year in funding.
Fertiliser industry sources confirmed input of $5m a year was a ballpark figure to get the model calibrated to a higher degree of accuracy to make it a more valid tool to use in setting nutrient loss limits.
A report by Dr Doug Edmeades identified errors of minus 40% or plus 60% in the model’s predictive outcomes.
Prosser said his efforts raising the issue in Parliament were not to discredit Overseer or its purpose.
It was to push for more funding for the tool instrumental not only in establishing environmental standards in catchments but which had outcomes with fundamental impacts on farmers’ business profitability.
Prosser has support from Read who acknowledged the model needed more resources to be validated across the entire country.
“There is a lot more we know we can do but we do not have the resources to do at the moment. Calibration is one area we are trying to define better,” she said.
Overseer was funded in a three-way arrangement between the Fertiliser Association, Primary Industries Ministry and AgResearch, all contributing funds or payment in kind to the model’s continuing development.
The possibility of non-governmental funding was not something to rule out but Read said it would have to come with no strings attached.
“The model is the model.”
The model was developing with advances in science and priorities were becoming much clearer.
Read acknowledged the impact Overseer standards could have on farmers’ business decisions and that there was variance within the model’s accuracy on nutrient losses.
However, environmental regulations should not have to wait until the science caught up.
Councils were aware of the shortfalls in Overseer and work was being done to better understand where weaknesses lay and to ensure those issues were fed into regulatory and policy standards.
Getting a more accurate model of nitrogen loss levels was a priority, given the importance being put on it at a council level.
But Prosser said for a system that had been around for 20 years, shortfalls should have been ironed out by now.
Read challenged the 20-year claim.
“I think 20 years is a bit of a stretch to claim Overseer has been around for. It originated from an advisory tool used for fertiliser application and developed into a completely different model after that.
“It has realistically been around for 10 years and the latest version 6 is a step change from the version before.”
NZ First also highlighted a Country-wide article that detailed a cost of $4000-$6000 for a consultant to do an Overseer nutrient programme on a Canterbury mixed cropping farm.
“That figure is unusually high on grounds it was quite a complex farming system that also involved a lot of one-off set-up time that would not have to be invested again,” Read said.
