Their findings were recently published in an article in the Proceedings of the National Academy of Sciences (PNAS).
The PNAS article looked at the agricultural practices in eight countries, including New Zealand, and revealed governments imposed few restrictions on the types of pasture varieties planted by landowners.
The authors said governments should manage a list of prohibited varieties not just species, develop a weed risk assessment, ensure rapid detection and control of invasive weeds, and develop an industry-pays system.
If pastures became invasive then agribusiness and farmers should be responsible for paying for any control.
Professor Philp Hulme, who specialises in plant biosecurity at Lincoln University and co-authored the article, said pasture species such a ryegrass and fescue may not strike people as major threats to the environment, but they are regarded by the Department of Conservation as environmental weeds.
“Pasture is big business in NZ and a large part of our economic success arises from agribusiness developing ever more productive or persistent varieties. As a result there is a clear conflict between economic and conservation outcomes.
“(Resolving) this will be difficult in a country as dependent as we are on dairy exports for economic prosperity. I imagine the environmental risks of pasture species are not at the front of the minds of farmers or policymakers,” Hulme said.