For more than 40 years glyphosate has been an invaluable chemical weapon in farmers’ arsenal as a low-residue, safe and simple weed control enabling greater flexibility and less soil disturbance. Canterbury arable farmer Hamish Marr devoted his Nuffield Scholarship to examining how glyphosate fell from grace in the public eye and what farmers can to do to preserve it as an invaluable crop treatment. Richard Rennie reports.
After a year studying glyphosate use and the tendency by some broadacre farmers to use it as a blackboard duster Hamish Marr concluded some behaviour might have to change but the chemical’s value in enabling farmers to grow quality, low-residue food means it has to remain available.
That also comes with the condition consumers are better educated about the economic and environmental value it plays in modern farm systems.
“In some respects glyphosate has become a victim of circumstance.
“It became tangled up with the genetically modified organism debate in the mid nineties when Roundup-ready GM seed for canola, corn and soybeans was released by Monsanto.
“The scientists involved with that technology really believed they would be doing the world a favour,” Marr said.
Roundup ready seed meant the crop could be sprayed with glyphosate to eliminate weeds without damaging the crop itself.
It reduced the amount and types of other potentially more toxic sprays like atrazine that might otherwise be used.
With the GM debate starting to gain traction the link with Monsanto’s Roundup provided the fuel for opposition to glyphosate’s use that continues today.
“The real irony is that Roundup was close to being off patent when it was included in GMO crops and it is the generic companies that have benefited,” Marr said.
That opposition has only grown since on the back of claims it causes cancer, prompts a decline in bee populations and has dangerous residue levels.
“All the countries I travelled through with the exception of Japan and Indonesia are facing the same challenges around glyphosate and how to respond to claims about its effects.”
But the guarded response of governments about banning glyphosate outright suggests an appreciation modern farming cannot operate economically without it.
That is shared by all governments with the exception of Germany and France, which have agreed to ban glyphosate by 2023 despite vigorous arguments from farmers, industry and scientists about its essential role.
The French and German decisions also came despite European Union regulations preventing individual countries making such rules.
Clouding the issue even more a World Health Organisation report in 2015 initially found glyphosate was probably carcinogenic to humans. But that was contradicted a year later by another report from the same organisation stating it is unlikely to be a cancer risk.
Researchers point to safe maximum residue level or the highest amount allowed in food and doses required to be toxic.
The industry’s experience with glyphosate is also symbolic of a broader gap between farmers and consumers over how chemicals are used in modern agriculture.
“And one of the challenges I identified was how do we correct that with some sort of information loop back to consumers to better inform them?”
It could involve an educative website explaining the science and practice behind the herbicide. It could also highlight the quality of the food glyphosate has played a role in growing and how much more expensive that food would be without it.
In NZ the use of glyphosate is significantly lower than in broadacre cropping countries, simply because NZ is smaller and more pastoral dominant, Marr said.
The challenge for farmers is to treat glyphosate as a specialist tool and identify where in their cropping and pasture rotations it is the most important.
“We are fortunate in NZ that politics is largely left out of this discussion and it is up to the industry to do the right thing. If we were in Europe the decision would be made for us.
“On our farm we have reduced our use by no longer using glyphosate in pre-harvest weed control and many other farmers now are the same.”
NZ is so far ahead of the world in these types of issues because it generally includes grazing animals in cropping systems.
“We are in the main already doing what other countries are discovering and recommending.”
Marr estimates the chemical’s value to NZ agriculture at $300m to $500m a year across about 12,000ha a year treated with it.
While in Denmark he had an insight to the impact its removal could have on the seed industry he supplies.
“They are farming under the assumption it is going to go. As a result, their seed industry is moving offshore.”
The irony that NZ’s seed industry could benefit from that has not been lost on him.
Marr said the ethos of a Nuffield Scholarship is linking agriculture and food through people, delivering a greater understanding of farming and food production.
“Glyphosate should be looked at as a specialist tool that is critical in some aspects of agriculture and not the duster on the blackboard.
“It is up to agriculture to explain its why to the people.”