Effects of GM potato Modena on soil microbial activity and litter decomposition fall within the range of effects found for two conventional cultivars

• Published in: Biology and fertility of soils Vol. 51; no. 8; pp. 913 - 922
• Main Authors: Brolsma, Karst M, Vonk, J Arie, Hoffland, Ellis, Mulder, Christian, de Goede, Ron GM
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2015; Springer Nature B.V
• Subjects: Agriculture; Biomass; Biomedical and Life Sciences; Bodembiologie; Bodembiologie en biologische bodemkwaliteit; carbon; Chair Soil Biology and Biological Soil Quality; crops; Cultivars; Decomposition; field experimentation; flowering; Genetically altered foods; Leerstoelgroep Bodembiologie en biologische Bodemkwaliteit; Life Sciences; Litter; Microbial activity; Mineralization; Multivariate analysis; nitrogen; Organic matter; Original Paper; PE&RC; Potatoes; Rhizosphere; roots; senescence; Soil Biology; Soil Biology and Biological Soil Quality; Soil microorganisms; Soil moisture; Soil organic matter; Soil Science & Conservation; soil water; Solanum tuberosum; sucrose; transgenic plants; Vegetables; MicroResp; Home-field advantage; Carbon and nitrogen mineralization; Genetically modified crops; Risk assessment
• ISSN: 0178-2762; 1432-0789
• DOI: 10.1007/s00374-015-1031-2

Plant roots have a profound effect on soil microbial activity, particularly in the rhizosphere. Hence, it is important to understand the potential effects of genetically modified (GM) crops on soil microbial activity and related processes such as litter decomposition. In this study, we compared the effects of GM potato Modena on soil microbial activity and carbon (C) and nitrogen (N) mineralization to effects induced by Modena’s parental isoline (Karnico) and a conventional potato cultivar (Aventra). A field experiment was conducted at two sites to assess microbial catabolic diversity (using MicroRespᵀᴹ) in the rhizosphere and in bulk soil, during flowering and senescence of the potato plants. In a laboratory experiment with soil and potato litter from the field experiment, we investigated whether the cultivars had modified the activity of soil microbial communities to such an extent that this affected C and N mineralization. Results of the field experiment showed no GM-induced effects on microbial catabolic diversity, while effects of field site location and sampling date were significant. Multivariate analysis including plant traits and soil characteristics revealed that microbial catabolic activities in rhizosphere soil were strongly correlated with soil organic matter and tuber sucrose content, whereas in bulk soil, they were primarily correlated with soil moisture. In the laboratory experiment, we found that Modena induced a “home-field advantage” in N mineralization, yet this effect was inconsistent across locations and was also observed for other cultivars. Based on our data and results from previous studies, we conclude that the effects of GM cultivar Modena on soil microbial activity and litter decomposition fall within the normal range of effects found for conventional potato cultivars.