Fliessbach, Andreas; Messmer, Monika; Nietlispach, Bruno; Infante, Valentina and Mäder, Paul (2011) Effects of conventionally bred and Bacillus thuringiensis (Bt) maize varieties on soil microbial biomass and activity. Effects of conventionally bred and Bacillus thuringiensis (Bt), -, pp. 1-10.
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Genetically modified (GM) maize containing genes from the soil bacterium Bacillus thuringiensis (Bt) was cultivated on 29% of the total maize production area worldwide in 2009. Most studies to date compare Bt-maize varieties with their near isogenic lines; however, there is little information on the variability of conventional maize breeding lines and how the effects of Bt varieties are ranked within. In our study on the potential risks of Bt-maize varieties, we analyzed tissue quality and compared the effects of ten conventional and GM maize varieties on soil microbiological properties in a replicated climate chamber experiment. All maize varieties were cultivated twice in the same soil microcosm. Shoot yields and soluble C in leaf tissue of Bt varieties were higher than the ones of non-Bt. Soil dehydrogenase activity was reduced by 5% under Bt varieties compared to non-Bt, while most of the other soil microbial properties (soil microbial biomass, basal respiration) showed no significant differences between Bt and non-Bt varieties. The leaves and roots of one Bt variety were decomposed to a greater extent than the ones of its near isogenic line; the conventional breeding lines also showed higher values. Changes in crop and soil parameters were found when comparing the first and the second crops, but the effects of repeated cropping were the same for all tested varieties. For the studied parameters, the variation among non- Bt-maize varieties was similar to the difference between Bt and non-Bt varieties.
|EPrint Type:||Journal paper|
|Keywords:||Bt-maize, Soil fertility, Cry1Ab, GMO,Microbial biomass, Soil respiration, Dehydrogenase, Mycorrhiza|
|Subjects:|| Soil > Soil quality > Soil biology|
Crop husbandry > Production systems > Cereals, pulses and oilseeds
Crop husbandry > Breeding, genetics and propagation
|Research affiliation:|| Chile|
Switzerland > FiBL - Research Institute of Organic Agriculture Switzerland > Soil Sciences
|Deposited By:||Winter, Carmen|
|Deposited On:||09 Dec 2011 20:13|
|Last Modified:||16 Dec 2011 12:33|
|Refereed:||Peer-reviewed and accepted|
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