Jeremy Talbot, of Temuka, led a presentation against the Overseer system to ECan councillors recently alongside scientists Dr Gregorini from Lincoln, Dr Lucy Waldron, private consultant, and Ivan Lawrie from Foundation for Arable Research (Far).

They said the previous ECan council’s insistence on using Overseer has “seen another five-plus years of increased nitrates enter our water systems, and we are still unable to make it work” despite “throwing over $100 million at it”.

“Why is it that despite no one else in the world managing or wanting to use an effects based output system, did ECan insist that it was the only way?” Talbot asked of the system that claims to enable “farmers and growers to improve nutrient use on farms, delivering better environmental outcomes…”

“The answer I think is that ECan staff thought it would absolve them of any responsibility as they wouldn’t have to make the decisions. As of today, it hasn’t worked and in fact nitrate levels are still increasing at an alarming rate.”

Talbot, a former chairman of South Canterbury Federated Farmers’ arable section, also suggested there needed to be a change in what needed to be fed to cows on the farm.

“Cows can’t utilise protein levels above 15 to 16 per cent. The pastures in New Zealand are often double this or higher.

“So as the cows can’t utilise it, it comes out the cow’s rear end as a horizontal green waterfall that is very high in nitrates, e-coli and then methane from the burping due to the unbalanced rumen.

“If the diet is right, the dung comes out and forms a cowpat that sits on the surface and is broken down by sunlight and bacteria.”

Talbot said a way to balance the protein levels would be to grow “low protein” feeds such as maize or cereal silages, along with some grain as a base supplement.

“They are the most readily available feed that will grow almost anywhere … and produce three times the amount of feed for the same amount of water as the grass would use, and they are the cheapest.

“But they will also turn the high nitrate dairy effluent from the dairy sheds into high quality low protein feed to further reduce nitrates. When put together this could reduce nitrate losses by 70 per cent while increasing profits.”

Talbot also raised concerns about the fact that an increasing number of cows grazing under centre-pivot irrigators has led to serious ground compaction issues causing the pastures to become shallow and ponding above the ground.

“It also raises the protein levels in the pastures including organic farms.

“All of this leads to a very serious issue, this is when the autumn rains do arrive and then suddenly, we have all of this stored nitrates and E-coli suddenly released into our underground.

“I think that this council needs to start with a clean sheet approach, and in particular the approach in its consultation with farmers and recognised scientists that have all been ignored to date.”

ECan deputy chairman Peter Scott said Talbot raised “a number of interesting points”.

However, he said it was not up to ECan to set methods of farming.

“ECan’s role has been to set environmental limits that farmers are required to meet,” Scott said.

“It is for farmers to determine how they operate their farms to meet those limits.”

Scott said a lot of money had been invested in Overseer, and he expected its efficiency to improve over time.