(NaturalNews) The adoption of crops genetically modified (GM) for herbicide resistance leads to a dramatic increase in herbicide usage and herbicide resistance, and is a major threat to global biodiversity, according to a joint scientific report by the environmental agencies of Austria and Switzerland and the German nature conservation agency, BfN.
To top it off, such crops provide no yield benefit to farmers.
GM crops drive herbicide use
Although GM herbicide-resistant (HR) crops were widely adopted in some parts of the world following their introduction in the 1990s, they have mostly been banned in Europe. The report examines the likely effects of a change to the European policy -- a particularly relevant investigation given current proposals to move regulation of GM crops out of the hands of the European Union and back into the hands of individual nations.
From an agricultural perspective, the researchers note that studies show that the use of HR crops does not lead to larger harvests or increased food supply. "In general, there has been little, if any contribution of HR crops to increase the yield," they wrote.
Rather, HR crops are appealing to farmers because they reduce their costs, particularly given the currently low prices of herbicides. In addition, using HR crops makes weed management much simpler, enabling farmers to spray large doses of just one or two chemicals over an entire field, rather than adopting more customized methods such as strategic application of different herbicides, crop rotation, cover cropping or interplanting.
This simplicity comes at a cost, however. Although GM crop proponents often claim that HR crops facilitate lower herbicide use, the opposite is clearly the case. The report found that the introduction of HR crops into the U.S. did, in fact, lead to a drop in herbicide usage between 1996 and 2000. Since 2000, however, herbicide usage has climbed dramatically in every successive year.
The authors attribute this trend to the evolution of more and more herbicide-resistant weeds. This evolution was initially driven by farmers' over-reliance on just one or two types of herbicide (the kinds that their crops were resistant to). The evolution of these crops led to an increase in the amounts of herbicides used, which has only increased the selective pressure for the evolution of more and tougher HR weeds - leading in turn to ever greater herbicide use.
"It has been known for some time that intensive high input farming is one of the main drivers of ongoing biodiversity losses in agricultural landscapes," the report notes, and that "agricultural intensification and pesticide use are among the main drivers of biodiversity loss."
Studies have shown that the herbicides most commonly used on GM fields are toxic to everything from plants and mammals (including humans) to the microflora in soil, the report found. The researchers also noted that all destructive agricultural practices are intensified in GM fields: not just chemical use, but also monoculture cropping.
This loss of plant diversity in agricultural areas can devastate the food web by reducing food supplies for animals that feed on native plants, as well as all their predators.
"Farmland birds may be particularly affected," the authors wrote. "The significant reduction in monarch butterfly populations in the US has been linked to the widespread cultivation of HR crops in the Midwest, which drastically reduced the population of milkweed, the feeding plant of monarch larvae."
The report calls for an end to the practice of comparing GM crops only with conventionally grown, chemical-intensive non-GM crops. Instead, the authors suggest comparing both of these agricultural strategies with low-input agro-ecological systems. When compared with these systems, it quickly becomes obvious that GM crops are not advantageous, the authors wrote.
"Herbicide resistant crops are not part of the solution, but part of the problem," the report concludes.