Drawing on their recent work and other published studies, the team projected that pesticides and other contaminants are reducing plant yield by one-third as a result of impaired SNF. This remarkable conclusion suggests one mechanism, or explanation of the yield-enhancing benefits of well-managed, long-term organic farming systems. http://www.organic-center.org/science.hot.php?action=view&report_id=99

Furthermore this is all about monopoly not science :

On 17th December 2007 Monsanto was found guilty of contempt of the South African Advertising Authority (ASA) for publishing false claims about the safety of GM foods.

In January,2007, Monsanto was fined 15,000 euros (US$19,000 ) in a French court for misleading the public about the environmental impact of herbicide Roundup.

A former chairman of Monsanto Agriculture France was found guilty of false advertising for presenting Roundup as biodegradable and claiming that it left the soil clean after use. Monsanto’s French distributor Scotts France was also fined 15,000 euros.

In 2005 Monsanto was caught smuggling South African produced GM Bollgard cotton seed into Indonesia disguised as rice. Monsanto was fined for bribing Indonesian officials.

In 2006 Monsanto suppressed evidence of serious damage to the liver and kidneys of rats in their MON 863 GM maize trials until ordered to release this evidence by a German Court.

In June, 2007, a second peer-reviewed case involving another variation of Monsanto’s GM maize, namely, NK 603, has been shown by studies to be potentially toxic to humans. NK 603 has been approved for food, feed, processing, and propagation in Europe and the Philippines The new research, carried out by the French scientific research institute CRIGEN, involves biotech firm Monsanto’s NK 603 GMO corn (marketed commercially under the name Round-up Ready).

Rats that were fed GM maize showed significant differences in measurements, as well as significant weight differences compared to those fed with normal maize. Almost 70 statistically significant differences were observed and reported – 12 for hematology parameters, 18 for clinical chemistry parameters, nine for urine chemistry parameters, six for the organ weights (brain, heart, liver), 14 for body weights and body weight changes, and eight for food consumption. toxicity, The most alarming was the diminished brain size. Scientists warned that diminished brain size sent out a urgent danger warning for growing children fed `GM food.