Effects of genetically modified plants on soil microorganisms. In Mitchell, R. and Ji-Dong, G

Despite the ongoing debate on potential risks of the wide-scale application and commercial use of genetically modified (GM) crops, in particular in Europe, the number of countries planting GM crops increased to 23, comprising 12 developing countries and 11 industrial countries in 2007. Table 10.1 provides an overview of countries growing 50,000 ha or more of GM crops and the type of crop planted (modified according to James, 2007). The application of GM plants in agriculture and forestry (eg, with the aim of increased pest resistance) could lead to a significant reduction in the release of pesticides into the environment. Therefore, the use of GM crops may be considered as environmental friendly. However, the overall impacts of GM crops on soil quality are poorly understood. Despite their importance for soil and plant health, the response of soil microbes to the large-scale application of GM crops has not been addressed adequately in many studies, simply due to the lack of appropriate methods to do so. It is assumed that changes in soil microbial community composition might occur directly, due to the biological activity of the transgene products, or indirectly,