Scientists: GM crops can play role in sustainable agriculture

Genetically modified (GM) crops may contribute to increased productivity in sustainable agriculture, according to a major study published in the June 8 issue of the journal Science. The research analyzes, for the first time, environmental impact data from field experiments all over the world, involving corn and cotton plants with a Bt gene inserted for its insecticidal properties.

The analysis [*abstract] was conducted by scientists at the National Center for Ecological Analysis and Synthesis (NCEAS) at the University of California, Santa Barbara, The Nature Conservancy, and Santa Clara University. The study is accompanied by a searchable global database for agricultural and environmental scientists studying the effects of genetically engineered crops ("Nontarget Effects of Bt Crops" database).

Biotechnology and genetic engineering are controversial because of concerns about risks to human health and biodiversity, but few analyses exist that reveal the actual effects genetically modified plants have on other non-modified species. In an analysis of 42 field experiments, scientists found that this particular modification, which causes the plant to produce an insecticide internally, can have an environmental benefit because large-scale insecticide spraying can be avoided. Organisms such as ladybird beetles, earthworms, and bees in locales with “Bt crops” fared better in field trials than those within locales treated with chemical insecticides.

“This is a groundbreaking study and the first of its kind to evaluate the current science surrounding genetically modified crops. The results are significant for how we think about technology and the future of sustainable agriculture.” - Peter Kareiva, chief scientist of The Nature Conservancy

According to lead author, Michele Marvier, of Santa Clara University, says the research for the first time provides an answer the question: do Bt crops have effects on beneficial insects and worms? The answer is that it depends to a large degree upon the type of comparison one makes. When Bt crops are compared to crops sprayed with insecticides, the Bt crops come out looking quite good. But when Bt crops are compared to crops without insecticides, there are reductions of certain animal groups that warrant further investigation. What is clear is that the advantages or disadvantages of GM crops depend on the specific goals and vision for agroecosystems:
biofuels :: energy :: ethanol :: biomass :: bioenergy :: energy crops :: agriculture :: biotechnology :: GM crops :: insecticides :: sustainability ::

As NCEAS Director, Jim Reichman explains, “This important study by an interdisciplinary research team reveals how an in-depth analysis of large quantities of existing data from many individual experiments can provide a greater understanding of a complex issue. The project is enhanced by the creation of a public database, Nontarget Effects of Bt Crops, developed by NCEAS ecoinformatics expert, Jim Regetz, that will allow other scientists to conduct congruent analyses.”

But GM crops are not only controversial for environmental reasons. Scientists have found that so-called 'terminator seeds' have had devastating social effects in some developing countries. These GM seeds make poor farmers dependent on multinationals, from which they have to buy new seeds every season. Traditionally, farmers use their knowledge and the seeds from their harvested crops to grow new plants the next season. But with the introduction of GM seeds both this knowledge and self-sustenance gets lost, as it was recently outlined in an interesting anthropological study of farmers in Warangal, India (earlier post).

So even though the new public database on "Nontarget Effects of Bt Crops" will be very useful in studying the environmental effects of GM crops across the world, a similar database of socio-economic effects on local communities would be welcome too.

The debate on GM crops is becoming increasingly important in the context of bioenergy and biofuels. In some countries, GM crops are already being used on a large scale for the production of ethanol (corn, maize) and biodiesel (canola, rapeseed), and serious research efforts are underway to develop next-generation genetically engineered energy crops that can be engineered in such a way that their properties allow for more efficient bioconversion. Major genome sequencing initiatives for biomass crops have been launched in the EU and the US, with the poplar - a potential energy crop - being the first tree to have had its entire genome revealed. Likewise, the cassava genome is being sequenced with the aim of improving starch production.


More information:
Michelle Marvier, Chanel McCreedy, James Regetz, Peter Kareiva, "A Meta-Analysis of Effects of Bt Cotton and Maize on Nontarget Invertebrates", Science, 8 June 2007:
Vol. 316. no. 5830, pp. 1475 - 1477, DOI: 10.1126/science.1139208

National Center for Ecological Analysis and Synthesis: New Study Finds Genetically Engineered Crops Could Play a Role in Sustainable Agriculture [*.pdf] - June 7, 2007.

Biopact: Plant scientists develop new tool to protect crops from modified genes - February 26, 2007

Biopact: Anthropological study explores the effects of genetically modified crops on developing countries - January 27, 2007

Biopact: The first tree genome is published: Poplar holds promise as renewable bioenergy resource - September 14, 2006