Calling on science to help with nutrient decisions

20:40, May 27 2014

An award-winning Taupo beef farmer has called on agricultural scientists to frame any future animal productivity research around what effect it would have on his nutrient footprint.

Any future research had to focus on finding ways to increase production under environmental limits, Mike Barton said at a recent field day on his farm in western Taupo.

Barton and his wife Sharon were the supreme winner of the Farm Environment Awards for the Waikato region.

They farm under a nitrogen (N) cap and their N management and farm consent are calculated according to the software program Overseer.

The program has been adopted by many regional councils across the country as a regulatory tool for farmers to manage their nutrient budget.

Any further science around production or productivity increases was of no value unless it was modelled through Overseer, Barton said.


"It's of no value unless it describes production increases that I get for every kilogram of N that I leach."

That meant that science had to reframe what it thought about its role. In the past science had been very good at increasing on farm production. Now it had to look at increasing production within limits, he said.

Barton has a 25-year commitment to Landcare Research to allow the group to use his 142 hectare farm for scientific trials. The farm is also part of three other trials with AgResearch.

In one of these trials 1000 ceramic cups were used to collect N to help him understand how much N Barton leached.

"I needed to believe in Overseer and I needed to believe it was for real and we are one of the few farms where I actually know what I leach rather than having it modelled for me."

The resulting figures confirmed to Barton that Overseer was a valid model.

It now "rules our lives", Barton said.

The cost of this trial showed it was impossible to expect every farmer in the country to know what they were leaching.

That meant relying on models and Overseer was the best farmers had got, despite its problems, he said.

Science also had to start selecting and breeding animals that were more efficient in converting grass into protein.

"We have to start doing that work because there is so much wasted product going out in the urine polluting our waterways but if we could keep that within the animal, imagine how much faster they would grow."

He believed scientists and regional authorities would have to make some hard decisions around cultivation.

A paddock with a crop rotation that went from a strip grazed winter crop, followed by a summer crop and then in the following autumn had a permanent pasture established could leach 150-200kg of N, which was more than a dairy farmer, Barton said.

He urged farmers and regulators to have discussions about that issue now rather than ignoring the problem.

Barton believed the solution was for scientists to develop truly permanent pastures. If it cost Barton 200kg of N leached to establish a pasture that only lasted 10 years, that was 20kg of N per year that he had to add to his farm system.

"If I had a pasture that lasted 100 years, that's only 2kg a year. Now we'll probably struggle to get seed companies to fund that sort of research.

"Let's be real about this and stop walking away from it. A permanent pasture is something that lasts for over 100 years.

"I need science to tell me how to establish those pastures and I need science to tell me how to maintain them."

He also needed science to tell him how he could better articulate his environmental performance.

Science also needed to work with regional councils so he knew if he was doing the right thing, then he had a verification process.

"If I am making claims in a market overseas, I can verify those.

"Science has a role in verifying what we are doing as well as from a brand point of view.

"I don't believe we can have conversations around protecting water quality without having a parallel set of conversations around redefining the farm business model."

Farmers had to start achieving additional brand value from their produce which would see consumers paying for the cost of this work and for establishing water quality regimes."We have to get the funding from the increased value in the products that we sell.'

Waikato Times