Agricultural reality shows no yield benefit for GM

January 2014

Conventional wheat in Hertforshire, England. CC photo from Flickr

During a conference in Z├╝rich in 2010, molecular-biologist, Professor Jack Heinemann heard an off-hand remark from an economics professor which raised his eyebrows.  The comment was that because Europe has shunned GMOs, it had lost productivity compared to the US where most staple commodity crops are now largely GM.
Even at the time, a spot check of corn yields on the UN Food and Agriculture Organisation data-base during the first fifteen years of the GM era indicated that yields for corn were neck and neck on either side of the Atlantic.
This led Heinemann to make a more detailed comparison of 'like-for-like' crops in America and Europe. 

He extracted data for oilseed rape and maize which had the same growing seasons, were grown at the same latitude, and were managed under equally developed agri-systems.  This revealed little difference in yield between the US near-GM-saturated crops and the EU ones with minimal GM.
Yield comparison through the years 1961 to 2010* showed huge improvements over time on both sides of the Atlantic due to conventional breeding and management changes.  In the last 10 years of the GM era, yield increase was, if anything, marginally better in Europe.
*Note. GM commodity crops were introduced in 1996 
During 2013, Heinemann and others looked more closely at the whole agricultural reality of today. 
The first yardstick for crop 'success' is productivity in terms of yield per unit land area.  However, people of the future have to be fed too: this makes the underlying reliability and sustainability of that productivity  over time even more important.
In practical terms, the success of a crop depends on many factors, any one of which can act to boost or reduce crop success.  For example: crop genetics combined with environmental quality (soil, water, weather, pests); also, attendant costs (inputs, development, regulatory requirements); and political support (subsidies, trade agreements, property rights).
The recent lower crop success in America (and Canada) compared with Europe has been linked to some very telling features, for example:
  • higher pesticide use
  • a concentrated and monopolistic agri-input industry
  • stagnation or decline in genetic diversity stemming from fewer available seed options 
  • Note. Even within Europe, farmers' choice of maize seed varieties was found to be lower in Spain, where GM has been adopted, compared with other European countries (Hilbeck)
  • high annual variations in yield demonstrating a lack of resilience in the crop varieties used and in the management systems
  • increased farm size and a resulting narrowing of farming skills
  • large government subsidies
  • decreased public good research funding and breeding programmes 
Put another way, the American focus has been on growing crop varieties exhibiting maximised yields under ideal conditions.  This makes them easy to get past the regulators and easy to sell to farmers.  However, under 'normal' non-ideal conditions of multiple environmental stresses, the yields achieved in the field only occasionally match the hype.  With their lack of built-in resilience or diversity, crop failures are inevitable.  Add to this, the erosion of farming- and breeding-skills promoted by government subsidies and the need for crop-uniformity to manage such huge farms efficiently. 

COMMENT  It's no coincidence that this same blinkered US focus on ideal yield also generates maximum profit for the agri-input industry.
Heinemann notes that the vulnerability arising from over-planting of an over-uniform crop driven by economic and legislative forces was already recognised in 1970 in the wake of the collapse of the US maize crop due to southern corn leaf blight.  This disaster had been predicted twelve years previously by the inventor of the then novel hybrid production technique which came to be over-used.  As far back as 1939 a warning about the correlation between genetic diversity and susceptibility to disease was published.


Heinemann comments that many GM crops may not be, per se, a problem.  What they are however is another nail in the coffin of food production sustainability.
There seems little excuse for America to be using an agri-system with serious, inherent weaknesses which were recognised decades ago, and less excuse for promoting an agri-system which puts industry profits before the well-being of the future.
2013 will go down as the year when the inferiority of GM crops over conventional varieties became concrete.
New Year's Resolution: make 2014 the year of the end of GM in the food chain.
Remember also that,  besides the factors associated with reduced crop success in America detailed above, GM crops are linked to other long-term problems, for example, declining soil health and climate change [1], and heavily processed, health-damaging foods [2].



Jack A. Heinemann et al., 2013, Sustainability and innovation in staple crop production in the US Midwest, International Journal of Agricultural Sustainability,

Angelika Hilbeck et al., 2013, Farmer's choice of seeds in four EU countries under different levels of GM crop adoption, Environmental Sciences Europe 25:12

Sven-Erik Jacobsen et al., 2013, Feeding the world: genetically modified crops versus agricultural biodiversity, Agronomic Sustainable Development

Jill Richardson, Study: Monsanto GMO food  claims probably false,, 27.06.13

Eva Sirinathsinghji, US Staple Crop System Failing from GM and Monoculture, Institute of Science in Society Report 10.07.13

GM a failing biotechnology in modern agro-ecosystems, University of Canterbury press release, 18.06.13

GM Watch Q&A with the authors of the Heinemann study, 18.06.13

No comments:

Post a comment

Thanks for your comment. All comments are moderated before they are published.