Soil Association report on GM crops

The Soil Association has published a report on the latest available research on GM crop yields over the last ten years. The yields of all major GM crop varieties in cultivation are lower than, or at best, equivalent to, yields from non-GM varieties. According to Peter Melchett, Soil Association policy director, GM chemical companies constantly claim they have the answer to world hunger while selling products which have never led to overall increases in production, and which have sometimes decreased yields or even led to crop failures.

An April 2006 report from the United States Department of Agriculture (USDA), for example, states that “currently available GM crops do not increase the yield potential of a hybrid variety. In fact, yield may even decrease if the varieties used to carry the herbicide tolerant or insect-resistant genes are not the highest yielding cultivars”. Studies from 1999 - 2007 consistently show RR GM soya to yield 4 – 12% lower than conventional varieties. A 2007 study by Kansas State University agronomist Dr. Barney Gordon suggests that Roundup Ready soya continues to suffer from a yield drag: RR soya yielded 9% less than a close conventional relative. Only maize shows a persistent trend of yield increase into the biotech era, but even here the rate of increase is no greater after than before biotech varieties were introduced.
 
Despite claims of increased yield, Bt cotton has had no significant impact in real terms. Average cotton yields have increased 5-fold since 1930, and staged an impressive surge from1980 to the early 1990s. Cotton yields then went flat, and continued to stagnate during the seven years of GM cotton’s rise to dominance. The steep yield and production increases in 2004 and 2005 were chiefly attributable to excellent weather conditions.

During the Government's 2003 'national debate' on whether or not to allow commercial planting of GM crops, the Royal Institute of Chartered Surveyors, which represents land agents amongst others, predicted 'long-term chaos' and possible declines in land values if GM crops were planted. Recent research in Sweden has confirmed that GM seeds can remain active in farmland for at least 10-years, adding scientific support to the RICS's concern about the impact on land values of growing GM crops.

 http://www.soilassociation.org