Does Bt maize have an effect on the soil?

Genetically modified Bt maize produces an insecticide, Bt protein, that kills the pests that feed on the plant. The Bt protein also enters the soil, primarily through rotting plant remains. Could it harm organisms that live on or in the soil? Does it have an impact on micro-organisms living in the soil and therefore on soil quality? Could it accumulate in the soil? Scientists at the Johann Heinrich von Thünen Institute (vTI) in Braunschweig have been researching these issues for years. So far they have tested three different Bt maize varieties. They are currently examining one that contains a combination of three different Bt proteins. GMO Safety spoke to Project Director Christoph Tebbe about the findings to date.

Research Live

Pollen diet for caterpillars

January 2010. It is below freezing outside, but in a greenhouse at RWTH Aachen University winter has been kept at bay and clouds of butterflies are fluttering about in a carefully controlled atmosphere in a large tent-like net. Mechthild Schuppener has succeeded in establishing a breeding programme for small tortoiseshell butterflies. She needs small caterpillars for feeding experiments that she is conducting in the laboratory. She is trying to find out whether genetically modified Bt maize is harmful to butterflies.more

Research Live

After havesting, the plant residue remaining on the field is collected at different time points to investigate the decomposition of the mulch and the microorganisms involved.

Maize litter and micro-organisms

It is the middle of April and there is stubble as far as the eye can see. There are still a few weeks left until the next crop of maize will be sown and the trial field lies abandoned. Scientists from Müncheberg have arrived to collect samples of the maize litter that was left on the field after the harvest last autumn. They are investigating whether the cultivation of Bt maize has an impact on soil-dwelling bacteria and fungi that break down maize litter. more

Research Results

“Looking at all the results, we can assume that cultivation of this maize does not pose a problem.”

From 2005 to 2008, a joint biosafety research group studied genetically modified MON88017 Bt maize, which has a new gene that makes it resistant to the Western corn rootworm. The research findings are now available. GMO Safety spoke to Stefan Rauschen of RWTH Aachen University, who has been coordinating the biosafety research into genetically modified maize since 2008. more

Research Maize

Maize harvest: Here the whole plants are harvested.

Comparing different varieties

From 2008 to 2011 several research projects will once again be investigating the environmental impacts of genetically modified Bt maize. A field trial was set up for this purpose to compare Bt maize with different conventional varieties. This series of research projects is being funded by the German Ministry of Education and Research (BMBF) as part of its biological safety research programme. BioSafety documented the work in the field trial from the sowing to the harvest.more

Research Live

Bees at the hive entrance

“We are looking at how bee colonies that can gather pollen from only one type of maize develop.”

The maize test area in the middle of August. Gauze-covered tents, distributed over the whole maize test area, represent the restricted habitat for the bees during the maize flowering season, each with two bee colonies. For the maize plants the space in the tents is rather cramped; their tops are bent under the three-meter high net. This flowering season is the crucial time for the bee trials of Stephan Härtel and his co-workers from the University of Bayreuth, since only then can the bees gather the maize pollen.more