The trials are an emotive issue in Britain and the government has issued a cautious response, saying it will take further advice before making policy. But the trials leave a number of environmental questions unanswered. Although they're being presented as comparing GM crops with conventional varieties, in fact they're comparing different herbicides - the modern ones used on GM fields against the older chemicals used on non-GM varieties - and one of those older chemicals, atrazine, has just been banned by the EU. The trials didn't study the impact of genes moving from GM plants into the environment. However the results are interpreted in Britain, the scientists emphasise that they don't automatically apply to other crops and other countries; but they suggest this kind of trial is a model other nations might use in evaluating whether to introduce GM crops.