A Systematic Review of the Environmental Impacts of GM Crop Cultivation as Reported from 2006 to 2011


The current generation of genetically modified crops have shown potential to enhance agricultural productivity and alter farm production economics, but there remains global divergence in adoption of the technology due in part to uncertainty in the underlying science. In an attempt to address this, a systematic review was undertaken, which asked the question “What are the environmental impacts of the global cultivation of GM crops?” A database search statement generated over 19000 hits, which distilled down to 28 articles from which data was recovered to generate a set of R values, where R was the ratio of the GM divided by the conventional field data. Meta-analysis of this data indicated that under GM R had significantly increased from a background level of 1 to a mean value of 1.31. This increase in R, although positive, is not indicative of an environmental benefit due to the difficulty in assigning either benefits or disadvantages to the many indicators that were encompassed within the review. Subsequent regression analysis indicated that there was no standard model to explain the observed variation in R values. However, in models for both cotton and maize, variables relating to the design of the study had a significant effect, but these variables were not related to trait or gene insertion and were generally either year, country or change in cultivation practice in origin. Narrative analysis of the authors published interpretations indicated GM had no adverse effects in 85% of papers, 10% reported a beneficial effect and only 5% a deleterious impact. The conclusion of this study is that GM adoption has had an impact on its environment, but that the underlying cause of this impact is not due to the genetic modification and the effect on the environment is generally seen as not being adverse.

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O. Knox, C. Hall, A. McVittie, R. Walker and B. Knight, "A Systematic Review of the Environmental Impacts of GM Crop Cultivation as Reported from 2006 to 2011," Food and Nutrition Sciences, Vol. 4 No. 6A, 2013, pp. 28-44. doi: 10.4236/fns.2013.46A004.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] C. James, “Global Status of Commercialized Biotech/GM Crops,” ISAAA, Brief 42, Ithaca, 2010.
[2] D. A. Andow, G. L. Lovei and S. Arpaia, “Ecological Risk Assessment for Bt Crops,” Nature Biotechnology, Vol. 24, No. 7, 2006, pp. 749-751. doi:10.1038/nbt0706-749
[3] M. Marvier, C. McCreedy, J. Regetz and P. Kareiva, “A Meta-Analysis of Effects of Bt Cotton and Maize on Nontarget Invertebrates,” Science, Vol. 316, No. 5830, 2007, pp. 1475-1477. doi:10.1126/science.1139208
[4] A. Balog, J. Kiss, D. Szekeres, A. Szenasi and V. Marko, “Rove Beetle (Coleoptera: Staphylinidae) Communities in Transgenic Bt (MON810) and near Isogenic Maize,” Crop Protection, Vol. 29, No. 6, 2010, pp. 567-571. doi:10.1016/j.cropro.2009.12.020
[5] A. Ricroch, J. Berge and M. Kuntz, “Is the German Suspension of MON810 Maize Cultivation Scientifically Justified?” Transgenic Research, Vol. 19, No. 1, 2010, pp. 1-12. doi:10.1007/s11248-009-9297-5
[6] G. Brookes and P. Barfoot, “GM Crops: The Global Economic and Environmental Impact—The First Nine Years 1996-2004,” AgBioForum, Vol. 8, No. 2-3, 2005, pp. 187-196.
[7] G. P. Fitt, “Have Bt Crops Led to Changes in Insecticide Use Patterns and Impacted IPM?” Integration of InsectResistant Genetically Modified Crops within IPM Programs, Vol. 5, 2008, pp. 303-328.
[8] G. Brookes and P. Barfoot, “GM Crops: The First Ten Years-Global Socio-Economic and Environmental Impacts,” ISAAA, Ithaca, 2006.
[9] O. G. G. Knox, G. A. Constable, B. Pyke and V. V. S. R. Gupta, “Environmental Impact of Conventional and Bt Insecticidal Cotton Expressing One and Two Cry Genes in Australia,” Australian Journal of Agricultural Research, Vol. 57, No. 5, 2006, pp. 501-509. doi:10.1071/AR05366
[10] H. J. Beckie, K. N. Harker, L. M. Hall, S. I. Warwick, A. Legere, P. H. Sikkema, G. W. Clayton, A. G. Thomas, J. Y. Leeson, G. Seguin-Swartz and M. J. Simard, “A Decade of Herbicide-Resistant Crops in Canada,” Canadian Journal of Plant Science, Vol. 86, No. 4, 2006, pp. 12431264.
[11] G. A. Kleter, R. Bhula, K. Bodnaruk, E. Carazo, A. S. Felsot, C. A. Harris, A. Katayama, H. A. Kuiper, K. D. Racke, B. Rubin, Y. Shevah, G. R. Stephenson, K. Tanaka, J. Unsworth, R. Wauchope and S. S. Wong, “Altered Pesticide Use on Transgenic Crops and the Associated General Impact from an Environmental Perspective,” Pest Management Science, Vol. 63, No. 11, 2007, pp. 1107-1115. doi:10.1002/ps.1448
[12] A. Lang and M. Otto, “A Synthesis of Laboratory and Field Studies on the Effects of Transgenic Bacillus Thuringiensis (Bt) Maize on Non-Target Lepidoptera,” Entomologia Experimentalis et Applicata, Vol. 135, No. 2, 2010, pp. 121-134. doi:10.1111/j.1570-7458.2010.00981.x
[13] F. Widmer, “Assessing Effects of Transgenic Crops on Soil Microbial Communities,” Green Gene Technology: Research in an Area of Social Conflict, Vol. 107, 2007, pp. 207-234. doi:10.1007/10_2007_047
[14] G. Brookes and P. Barfoot, “GM Crops: Global SocioEconomic and Environmental Impacts 1996-2009,” PG Economics Ltd., Dorchester, 2011.
[15] G. L. Lovei, D. A. Andow and S. Arpaia, “Transgenic Insecticidal Crops and Natural Enemies: A Detailed Review of Laboratory Studies,” Environmental Entomology, Vol. 38, No. 2, 2009, pp. 293-306. doi:10.1603/022.038.0201
[16] G. B. Stewart, C. F. Coles and A. S. Pullin, “Applying Evidence-Based Practice in Conservation Management: Lessons from the First Systematic Review and Dissemination Projects,” Biological Conservation, Vol. 126, No. 2, 2005, pp. 270-278. doi:10.1016/j.biocon.2005.06.003
[17] Centre for Evidence-Based Conservation,”Guidelines for Systematic Review in Environmental Management,” Version 4.0., 2010.
[18] L. Wolfenbarger, S. E. Naranjo, J. G. Lundgren, R. J. Bitzer and L. S. Watrud, “Bt Crop Effects on Functional Guilds of Non-Target Arthropods: A Meta-Analysis,” PLos One, Vol. 3, No. 5, 2008, p. e2118. doi:10.1371/journal.pone.0002118
[19] S. Lewis and M. Clarke, “Forest Plots: Trying to See the Wood and the Trees,” BMJ, Vol. 322, No. 7300, 2001, pp. 1479-1480. doi:10.1136/bmj.322.7300.1479
[20] B. S. Griffiths, S. Caul, J. Thompson, A. N. Birch, J. Cortet, M. N. Andersen and P. H. Krogh, “Microbial and Microfaunal Community Structure in Cropping Systems with Genetically Modified Plants,” Pedobiologia, Vol. 51, No. 3, 2007, pp. 195-206. doi:10.1016/j.pedobi.2007.04.002
[21] P. H. Krogh, B. Griffiths, D. Demsar, M. Bohanec, M. Debeljak, M. N. Andersen, C. Sausse, A. N. Birch, S. Caul, M. Holmstrup, L. H. Heckmann and J. Cortet, “Responses by Earthworms to Reduced Tillage in Herbicide Tolerant Maize and Bt Maize Cropping Systems,” Pedobiologia, Vol. 51, No. 3, 2007, pp. 219-227. doi:10.1016/j.pedobi.2007.04.003
[22] J. Cortet, B. S. Griffiths, M. Bohanec, D. Demsar, M. N. Andersen, S. Caul, A. N. E. Birch, C. Pernin, E. Tabone, A. de Vaufleury, X. Ke and P. H. Krogh, “Evaluation of Effects of Transgenic Bt Maize on Microarthropods in a European Multi-Site Experiment,” Pedobiologia, Vol. 51, No. 3, 2007, pp. 207-218. doi:10.1016/j.pedobi.2007.04.001
[23] J. Cortet, M. N. Andersen, S. Caul, B. Griffiths, R. Joffre, B. Lacroix, C. Sausse, J. Thompson and P. H. Krogh, “Decomposition Processes under Bt (Bacillus thuringiensis) Maize: Results of a Multi-Site Experiment,” Soil Biology and Biochemistry, Vol. 38, No. 1, 2006, pp. 195-199. doi:10.1016/j.soilbio.2005.04.025
[24] M. Debeljak, J. Cortet, D. Demsar, P. H. Krogh and S. Dzeroski, “Hierarchical Classification of Environmental Factors and Agricultural Practices Affecting Soil Fauna under Cropping Systems Using Bt Maize,” Pedobiologia, Vol. 51, No. 3, 2007, pp. 229-238. doi:10.1016/j.pedobi.2007.04.009
[25] M. Heard, S. Clark, P. Rothery, J. Perry, D. Bohan, D. Brooks, G. Champion, A. Dewar, C. Hawes, A. Haughton, M. May, R. Scott, R. Stuart, G. Squire and L. Firbank, “Effects of Successive Seasons of Genetically Modified Herbicide-Tolerant Maize Cropping on Weeds and Invertebrates,” Annals of Applied Biology, Vol. 149, No. 3, 2006, pp. 249-254. doi:10.1111/j.1744-7348.2006.00091.x
[26] L. G. Firbank, P. Rothery, M. J. May, S. J. Clark, R. J. Scott, R. C. Stuart, C. W. H. Boffey, D. R. Brooks, G. T. Champion, A. J. Haughton, C. Hawes, M. S. Heard, A. M. Dewar, J. N. Perry and G. R. Squire, “Effects of Genetically Modified Herbicide-Tolerant Cropping Systems on Weed Seedbanks in Two Years of Following Crops,” Biology Letters, Vol. 2, No. 1, 2006, pp. 140-143. doi:10.1098/rsbl.2005.0390
[27] D. W. Gibbons, D. A. Bohan, P. Rothery, R. C. Stuart, A. J. Haughton, R. J. Scott, J. D. Wilson, J. N. Perry, S. J. Clark, R. J. Dawson and L. G. Firbank, “Weed Seed Resources for Birds in Fields with Contrasting Conventional and Genetically Modified Herbicide-Tolerant Crops,” Proceedings of the Royal Society B—Biological Sciences, Vol. 273, No. 1596, 2006, pp. 1921-1928. doi:10.1098/rspb.2006.3522
[28] A. Balog, A. Szenasi, D. Szekeres and Z. Palinkas, “Analysis of Soil Dwelling Rove Beetles (Coleoptera: Staphylinidae) in Cultivated Maize Fields Containing the Bt Toxins, Cry34/35Ab1 and Cry1F x Cry34/35Ab1,” Biocontrol Science and Technology, Vol. 21, No. 3, 2011, pp. 293-297. doi:10.1080/09583157.2010.545104
[29] D. Szekeres, F. Kadar and J. Kiss, “Activity Density, Diversity and Seasonal Dynamics of Ground Beetles (Coleoptera: Carabidae) in Bt-(MON810) and in Isogenic Maize Stands,” Entomologica Fennica, Vol. 17, No. 3, 2006, pp. 269-275.
[30] H. Darmency, Y. Vigouroux, T. G. Garambe, M. RichardMolard and C. Muchembled, “Transgene Escape in Sugar Beet Production Fields: Data from Six Years farm Scale Monitoring,” Environmental Biosafety Research, Vol. 6, No. 3, 2007, pp. 197-206. doi:10.1051/ebr:2007007
[31] M. G. Cattaneo, C. Yafuso, C. Schmidt, C. Y. Huang, M. Rahman, C. Olson, C. Ellers-Kirk, B. J. Orr, S. E. Marsh, L. Antilla, P. Dutilleul and Y. Carriere, “Farm-Scale Evaluation of the Impacts of Transgenic Cotton on Biodiversity, Pesticide Use, and Yield,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 103, No. 20, 2006, pp. 7571-7576. doi:10.1073/pnas.0508312103
[32] D. Llewellyn, C. Tyson, G. Constable, B. Duggan, S. Beale and P. Steel, “Containment of Regulated Genetically Modified Cotton in the Field,” Agriculture, Ecosystems & Environment, Vol. 121, No. 4, 2007, pp. 419-429. doi:10.1016/j.agee.2006.11.019
[33] Y. Carriere, C. Ellers-Kirk, M. G. Cattaneo, C. M. Yafuso, L. Antilla, C. Huang, M. Rahman, B. J. Orr and S. E. Marsh, “Landscape Effects of Transgenic Cotton on NonTarget Ants and Beetles,” Basic and Applied Ecology, Vol. 10, No. 7, 2009, pp. 597-606. doi:10.1016/j.baae.2008.10.010
[34] J. Hofs, A. Schoeman and J. Pierre, “Diversity and Abundance of Flower-Visiting Insects in Bt and Non-Bt Cotton Fields of Maputaland (KwaZulu Natal Province, South Africa),” International Journal of Tropical Insect Science, Vol. 28, No. 4, 2008, pp. 211-219. doi:10.1017/S1742758408201682
[35] H. Y. Hu, X. X. Liu, Z. W. Zhao, J. G. Sun, Q. W. Zhang, X. Z. Liu and Y. Yu, “Effects of Repeated Cultivation of Transgenic Bt Cotton on Functional Bacterial Populations in Rhizosphere Soil,” World Journal of Microbiology & Biotechnology, Vol. 25, No. 3, 2009, pp. 357-366. doi:10.1007/s11274-008-9899-8
[36] K. R. Kumar, G. Chandrasehar and S. Ayyappan, “Assessment of Arthropod Communities in Transgenic and Conventional Cotton in Kancheepuram District, Tamil Nadu,” Journal of Ecobiology, Vol. 19, No. 3, 2007, pp. 201-207.
[37] R. S. Mann, R. S. Gill, A. K. Dhawan and P. S. Shera, “Relative Abundance and Damage by Target and NonTarget Insects on Bollgard and BollgardII Cotton Cultivars,” Crop Protection, Vol. 29, No. 8, 2010, pp. 793-801. doi:10.1016/j.cropro.2010.04.006
[38] N. V. V. S. Prasad and N. H. Rao, “Field Evaluation of Bt Cotton Hybrids against Insect Pest Complex under Rainfed Conditions,” Indian Journal of Entomology, Vol. 70, No. 4, 2008, pp. 330-336.
[39] J. Torres and J. Ruberson, “Abundance and Diversity of Ground-Dwelling Arthropods of Pest Management Importance in Commercial Bt and Non-Bt Cotton Fields,” Annals of Applied Biology, Vol. 150, No. 1, 2007, pp. 27-39. doi:10.1111/j.1744-7348.2006.00087.x
[40] S. Bourassa, H. Carcamo, J. Spence, R. Blackshaw and K. Floate, “Effects of Crop Rotation and Genetically Modified Herbicide-Tolerant Corn on Ground Beetle Diversity, Community Structure, and Activity Density,” Canadian Entomologist, Vol. 142, No. 2, 2010, pp. 143-159. doi:10.4039/n09-017
[41] J. R. Powell, D. J. Levy-Booth, R. H. Gulden, W. L. Asbil, R. G. Campbell, K. E. Dunfield, A. S. Hamill, M. M. Hart, S. Lerat, R. E. Nurse, K. Pauls, P. H. Sikkema, C. J. Swanton, J. T. Trevors and J. N. Klironomos, “Effects of Genetically Modified, Herbicide-Tolerant Crops and Their Management on Soil Food Web Properties and Crop Litter Decomposition,” Journal of Applied Ecology, Vol. 46, No. 2, 2009, pp. 388-396. doi:10.1111/j.1365-2664.2009.01617.x
[42] A. Schier, “Field Study on the Occurrence of Ground Beetles and Spiders in Genetically Modified, Herbicide Tolerant Corn in Conventional and Conservation Tillage Systems,” Journal of Plant Diseases and Protection, 2006, pp. 101-113.
[43] S. Demaneche, H. Sanguin, J. Pote, E. Navarro, D. Bernillon, P. Mavingui, W. Wildi, T. M. Vogel and P. Simonet, “Antibiotic-Resistant. Soil Bacteria in Transigenic Plant Fields,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 105, No. 10, 2008, pp. 3957-3962. doi:10.1073/pnas.0800072105
[44] M. Devare, R. Londono and J. Thies, “Neither Transgenic Bt Maize (MON863) nor Tefluthrin Insecticide Adversely Affect Soil Microbial Activity or Biomass: A 3-Year Field Analysis,” Soil Biology & Biochemistry, Vol. 39, No. 8, 2007, pp. 2038-2047. doi:10.1016/j.soilbio.2007.03.004
[45] G. P. Farinos, M. de la Poza, P. Hernandez-Crespo, F. Ortego and P. Castanera, “Diversity and Seasonal Phenology of Aboveground Arthropods in Conventional and Transgenic Maize Crops in Central Spain,” Biological Control, Vol. 44, No. 3, 2008, pp. 362-371. doi:10.1016/j.biocontrol.2007.11.007
[46] K. D. Floate, H. A. Círcamo, R. E. Blackshaw, B. Postman and S. Bourassa, “Response of Ground Beetle (Coleoptera: Carabidae) Field Populations to Four Years of Lepidoptera-Specific Bt Corn Production,” Environmental Entomology, Vol. 36, No. 5, 2007, pp. 1269-1274. doi:10.1603/0046-225X(2007)36[1269:ROGBCC]2.0.CO;2
[47] J. Frouz, D. Elhottova, M. Helingerova and F. Kocourek, “The Effect of Bt-Corn on Soil Invertebrates, Soil Microbial Community and Decomposition Rates of Corn PostHarvest Residues under Field and Laboratory Conditions,” Journal of Sustainable Agriculture, Vol. 32, No. 4, 2008, pp. 645-655. doi:10.1080/10440040802395098
[48] A. C. H. I. Gathmann, L. U. D. G. Wirooks, L. A. Hothorn, D. E. T. L. Bartsch and I. N. G. O. Sshuphan, “Impact of Bt Maize Pollen (MON810) on Lepidopteran Larvae Living on Accompanying Weeds,” Molecular Ecology, Vol. 15, No. 9, 2006, pp. 2677-2685. doi:10.1111/j.1365-294X.2006.02962.x
[49] I. Icoz, D. Saxena, D. A. Andow, C. Zwahlen and G. Stotzky, “Microbial Populations and Enzyme Activities in Soil in Situ under Transgenic Corn Expressing Cry Proteins from Bacillus thuringiensis,” Journal of Environmental Quality, Vol. 37, No. 2, 2008, pp. 647-662. doi:10.2134/jeq2007.0352
[50] R. Miethling-Graff, S. Dockhorn and C. C. Tebbe, “Release of the Recombinant Cry3Bb1 Protein of Bt Maize MON88017 into Field Soil and Detection of Effects on the Diversity of Rhizosphere Bacteria,” European Journal of Soil Biology, Vol. 46, No. 1, 2010, pp. 41-48. doi:10.1016/j.ejsobi.2009.10.003
[51] A. P. Oliveira, M. E. Pampulha and J. P. Bennett, “A Two-Year Field Study with Transgenic Bacillus thuringiensis Maize: Effects on Soil Microorganisms,” Science of the Total Environment, Vol. 405, No. 1-3, 2008, pp. 351-357. doi:10.1016/j.scitotenv.2008.05.046
[52] A. L. Priestley and M. Brownbridge, “Field Trials to Evaluate Effects of Bt-Transgenic Silage Corn Expressing the Cry1Ab Insecticidal Toxin on Non-Target Soil Arthropods in Northern New England, USA,” Transgenic Research, Vol. 18, No. 3, 2009, pp. 425-443. doi:10.1007/s11248-008-9234-z
[53] S. Rauschen, J. Eckert, F. Schaarschmidt, I. Schuphan and A. Gathmann, “An Evaluation of Methods for Assessing the Impacts of Bt-Maize MON810 Cultivation and Pyrethroid Insecticide Use on Auchenorrhyncha (Planthoppers and Leafhoppers),” Agricultural and Forest Entomology, Vol. 10, No. 4, 2008, pp. 331-339. doi:10.1111/j.1461-9563.2008.00394.x
[54] R. Rose and G. P. Dively, “Effects of Insecticide-Treated and Lepidopteran-Active Bt Transgenic Sweet Corn on the Abundance and Diversity of Arthropods,” Environmental Entomology, Vol. 36, No. 5, 2007, pp. 1254-1268. doi:10.1603/0046-225X(2007)36[1254:EOIALB]2.0.CO;2
[55] C. C. M. Van De Wiel, R. M. W. Groeneveld, O. Dolstra, E. J. Kok, I. M. J. Scholtens, J. T. N. M. Thissen, M. J. M. Smulders and L. A. P. Lotz, “Pollen-Mediated Gene Flow in Maize Tested for Coexistence of GM and Non-GM Crops in the Netherlands: Effect of Isolation Distances between Fields,” NJAS-Wageningen Journal of Life Sciences, Vol. 56, No. 4, 2009, pp. 405-423. doi:10.1016/S1573-5214(09)80007-9
[56] S. F. Yanni, J. K. Whalen and B. L. Ma, “Field-Grown Bt and Non-Bt Corn: Yield, Chemical Composition, and Decomposability,” Agronomy Journal, Vol. 103, No. 2, 2011, pp. 486-493.
[57] A. R. Zeilinger, D. A. Andow, C. Zwahlen and G. Stotzky, “Earthworm Populations in a Northern U.S. Cornbelt Soil Are Not Affected by Long-Term Cultivation of Bt Maize Expressing Cry1Ab and Cry3Bb1 Proteins,” Soil Biology and Biochemistry, Vol. 42, No. 8, 2010, pp. 1284-1292. doi:10.1016/j.soilbio.2010.04.004
[58] R. H. Gulden, P. H. Sikkema, A. S. Hamill, F. Tardif and C. J. Swanton, “Conventional vs. Glyphosate-Resistant Cropping Systems in Ontario: Weed Control, Diversity, and Yield,” Weed Science, Vol. 57, No. 6, 2009, pp. 665-672. doi:10.1614/WS-09-023.1
[59] N. Z. Lupwayi, K. G. Hanson, K. N. Harker, G. W. Clayton, R. E. Blackshaw, J. T. O’Donovan, E. N. Johnson, Y. Gan, R. B. Irvine and M. A. Monreal, “Soil Microbial Biomass, Functional Diversity and Enzyme Activity in Glyphosate-Resistant Wheat-Canola Rotations under LowDisturbance Direct Seeding and Conventional Tillage,” Soil Biology and Biochemistry, Vol. 39, No. 7, 2007, pp. 1418-1427. doi:10.1016/j.soilbio.2006.12.038
[60] E. Simpson, N. McRoberts and J. Sweet, “Out-Crossing between Genetically Modified Herbicide-Tolerant and Other Winter Oilseed Rape Cultivars,” Plant Genetic Resources Characterization and Utilization, Vol. 4, No. 2, 2006, pp. 96-107. doi:10.1079/PGR2005103
[61] G. Bodulovic, “Is the European Attitude to GM Products Suffocating African Development?” Functional Plant Biology, Vol. 32, No. 12, 2005, pp. 1069-1075. doi:10.1071/FP05049
[62] I. K. Crombie and H. T. Davies, “What Is Meta-Analysis?” What is...? Series, 2009, pp. 1-8.
[63] S. E. Naranjo, “Impacts of Bt Crops on Non-Target Invertebrates and Insecticide Use Patterns,” CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources, Vol. 4, No. 011, 2009, pp. 1-11. doi:10.1079/PAVSNNR20094011
[64] Monsanto Australia Limited, “Bollgard II Cotton Technical Manual,” 2003.

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