Do GM crops equal better yields? UC researchers say no

North American crop production has fallen behind that of Western Europe, despite US farmers using genetically modified (GM) seed and more pesticide, University of Canterbury researchers have found.

The main point of difference between the regions is the adoption of GM seed in North America and the use of non-GM seed in Europe, the researchers say.

The UC research team, led by Professor Jack Heinemann, compared data on agricultural productivity in North America and Western Europe from the last 50 years. The two regions were compared as they are similar in terms of the crops they grow, latitude and access to biotechnology, mechanisation and educated farmers.

“We found that the combination of non-GM seed and management practices used by Western Europe is increasing corn yields faster than the use of GM-led packages chosen by the US,” Heinemann said.

“Our research showed rapeseed (canola) yields increasing faster in Europe without GM than in the GM-led package chosen by Canada and decreasing chemical herbicide and even larger declines in insecticide use without sacrificing yield gains, while chemical herbicide use in the US has increased with GM seed.

“Europe has learned to grow more food per hectare and use fewer chemicals in the process. The American choices in biotechnology are causing it to fall behind Europe in productivity and sustainability.”

Heinemann says this raises the question of whether New Zealand should adopt US farming techniques, including GM-led biotechnology, or follow the high-performance agriculture demonstrated by Europe.

“Agriculture responds to commercial and legislative incentive systems. These take the form of subsidies, intellectual property rights instruments, tax incentives, trade promotions and regulation,” Heinemann said. “The incentive systems in North America are leading to a reliance on GM seeds and management practices that are inferior to those being adopted under the incentive systems in Europe.

“The decrease in annual variation in yield suggests that Europe has a superior combination of seed and crop management technology and is better suited to withstand weather variations. This is important because annual variations cause price speculations that can drive hundreds of millions of people into food poverty.

“We need more than agriculture; we need agricultures - a diversity of practices for growing and making food that GM does not support; we need systems that are useful, not just profit-making biotechnologies - we need systems that provide a resilient supply to feed the world well,” Heinemann said.

The research was published in the peer-reviewed International Journal of Agricultural Sustainability.