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Suggested Citation:"Front Matter." National Research Council. 2010. The Impact of Genetically Engineered Crops on Farm Sustainability in the United States. Washington, DC: The National Academies Press. doi: 10.17226/12804.

THE IMPACT OF GENETICALLY ENGINEERED CROPS ON FARM SUSTAINABILITY IN THE UNITED STATES

Board on Agriculture and Natural Resources

Division on Earth and Life Studies

NATIONAL RESEARCH COUNCIL
OF THE NATIONAL ACADEMIES

THE NATIONAL ACADEMIES PRESS

Washington, D.C.
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NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.

This study was funded by the National Academies. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the organizations or agencies that provided support for the project.

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Suggested Citation: National Research Council. 2010. The Impact of Genetically Engineered Crops on Farm Sustainability in the United States. Washington, DC: National Academies Press.

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THE NATIONAL ACADEMIES

Advisers to the Nation on Science, Engineering, and Medicine

The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Ralph J. Cicerone is president of the National Academy of Sciences.

The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Charles M. Vest is president of the National Academy of Engineering.

The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Harvey V. Fineberg is president of the Institute of Medicine.

The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Ralph J. Cicerone and Dr. Charles M. Vest are chair and vice chair, respectively, of the National Research Council.

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COMMITTEE ON THE IMPACT OF BIOTECHNOLOGY ON FARM-LEVEL ECONOMICS AND SUSTAINABILITY

DAVID E. ERVIN (Chair),

Portland State University, Oregon

YVES CARRIÈRE,

University of Arizona, Tucson

WILLIAM J. COX,

Cornell University, Ithaca, New York

JORGE FERNANDEZ-CORNEJO,

Economic Research Service, U.S. Department of Agriculture, Washington, DC¹

RAYMOND A. JUSSAUME, JR.,

Washington State University, Pullman

MICHELE C. MARRA,

North Carolina State University, Raleigh

MICHEAL D.K. OWEN,

Iowa State University, Ames

PETER H. RAVEN,

Missouri Botanical Garden, St. Louis

L. LAREESA WOLFENBARGER,

University of Nebraska, Omaha

DAVID ZILBERMAN,

University of California, Berkeley

Project Staff

KARA N. LANEY, Study Director

KAMWETI MUTU, Research Associate

ROBIN A. SCHOEN, Director,

Board on Agriculture and Natural Resources

KAREN L. IMHOF, Administrative Assistant

NORMAN GROSSBLATT, Senior Editor

¹	The views expressed here are those of the authors and may not be attributed to the Economic Research Service or the U.S. Department of Agriculture.

BOARD ON AGRICULTURE AND NATURAL RESOURCES

NORMAN R. SCOTT (Chair),

Cornell University, Ithaca, New York

PEGGY F. BARLETT,

Emory University, Atlanta, Georgia

HAROLD L. BERGMANN,

University of Wyoming, Laramie

RICHARD A. DIXON,

Samuel Roberts Noble Foundation, Ardmore, Oklahoma

DANIEL M. DOOLEY,

University of California, Oakland

JOAN H. EISEMANN,

North Carolina State University, Raleigh

GARY F. HARTNELL,

Monsanto Company, St. Louis, Missouri

GENE HUGOSON,

Minnesota Department of Agriculture, St. Paul

KIRK C. KLASING,

University of California, Davis

VICTOR L. LECHTENBERG,

Purdue University, West Lafayette, Indiana

PHILIP E. NELSON,

Purdue University, West Lafayette, Indiana

KEITH PITTS,

Marrone Bio Innovations, Davis, California

CHARLES W. RICE,

Kansas State University, Manhattan

HAL SALWASSER,

Oregon State University, Corvallis

PEDRO A. SANCHEZ,

The Earth Institute, Columbia University, Palisades, New York

ROGER A. SEDJO,

Resources for the Future, Washington, DC

KATHLEEN SEGERSON,

University of Connecticut, Storrs

MERCEDES VAZQUEZ-AÑON,

Novus International, Inc., St. Charles, Missouri

Staff

ROBIN A. SCHOEN, Director

KAREN L. IMHOF, Administrative Assistant

AUSTIN J. LEWIS, Senior Program Officer

EVONNE P.Y. TANG, Senior Program Officer

PEGGY TSAI, Program Officer

CAMILLA YANDOC ABLES, Associate Program Officer

KARA N. LANEY, Associate Program Officer

RUTH S. ARIETI, Research Associate

JANET M. MULLIGAN, Research Associate

KAMWETI MUTU, Research Associate

ERIN P. MULCAHY, Senior Program Assistant

Preface

Not since the introduction of hybrid corn seed have we witnessed such a sweeping technological change in U.S. agriculture. Hundreds of thousands of farmers have adopted the first generation of genetically engineered (GE) crops since their commercialization in 1996. Although not all GE varieties that have been commercialized have succeeded, those targeted at improved pest control now cover over 80 percent of the acres planted to soybean, cotton, and corn—that is, almost half of U.S. cropland. Forecasts suggest an expansion in GE-crop plantings in many other countries.

GE crops originate in advances in molecular and cellular biology that enable scientists to introduce desirable traits from other species into crop plants or to alter crop plants’ genomes internally. Those powerful scientific techniques have dramatically expanded the boundaries that have constrained traditional plant breeding. A new technology adopted so widely and rapidly has substantial economic, social, and environmental impacts on farms and their operators. Inevitably, both advantages and risks or losses emerge from such massive changes. The National Research Council has conducted multiple studies of specific aspects of GE crops, such as regulatory-system adequacy and food safety. However, the assigned tasks restricted the scope of their reports. As pressure mounts to expand the use of GE crops for energy, food security, environmental improvement, and other purposes, the scope and intensity of impacts will grow. Now is an opportune time to take a comprehensive look at the track record of GE crops and to identify the opportunities and challenges loom-

ing on the horizon. The National Research Council therefore supported the Committee on the Impact of Biotechnology on Farm-Level Economics and Sustainability to investigate this topic.

Despite the rapid spread of GE crops in U.S. agriculture, the technology continues to stir controversy around scientific issues and ideological viewpoints. The committee focused on the scientific questions associated with the farm-level impacts of the adoption of genetic-engineering technology and refrained from analyzing ideological positions, either pro or con. The committee adopted an “evidentiary” standard of using peer-reviewed literature on which to form our conclusions and recommendations. It is my hope that the report will give readers a firm grasp of the state of evidence or lack thereof on the scientific issues.

True to its charge, the committee adopted a sustainability framework that required an evaluation of environmental, economic, and social impacts of GE crops. Those three dimensions constitute the essential pillars of sustainability science. The summary and opening and closing chapters bring together the three perspectives for a fuller view of the technology’s impact.

Given the controversies, readers will want to know the committee’s composition and how it conducted its work in arriving at conclusions and recommendations. The biographies in Appendix C show a group of highly accomplished natural and social scientists who possess a broad array of research experience and perspectives on GE crops. That diversity of disciplines and expertise proved beneficial in introducing checks and balances in evaluating information from many angles. The committee members divided into teams to work on the various sections of the report on the basis of the members’ expertise. The drafts by each team were reviewed by the full committee to ensure that everyone had a chance to comment on and improve and approve each section. I was continually impressed with the members’ dedication to a hard-nosed and impartial evaluation of the best science on GE crops. Equally important, they kept open minds in considering new evidence presented by their colleagues and external experts. The result was a model multidisciplinary research process in which each of us learned from the others and improved the report quality.

In closing, I want to express my deep appreciation to the committee members for their tireless work and good humor in completing such a challenging task while working full time at their regular jobs. Their commitment and professionalism exemplify the best of public science. Each member made significant contributions to the final report. The committee also benefited from the testimony of several experts in the field and from the numerous comments of many conscientious external reviewers.

Finally, the quality of the report would not have been attained without excellent support and substantive input by study director Kara Laney, the valuable assistance of Kamweti Mutu, the insightful counsel of Robin Schoen, and the editorial work of the National Research Council.

David E. Ervin, Chair

Committee on the Impact of Biotechnology on Farm-Level Economics and Sustainability

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Acknowledgments

This report has been reviewed in draft form by persons chosen for their diverse perspectives and technical expertise in accordance with procedures approved by the National Research Council Report Review Committee. The purpose of the independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional standards of objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their review of the report:

Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations, nor did they see the final draft of the report before its release. The review of the report was overseen by Drs. Alan G. McHughen, University of California, Riverside, and May R. Berenbaum, University of Illinois, Urbana-Champaign. Appointed by the National Research Council, they were responsible for making certain that an independent examination of the report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of the report rests with the authoring committee and the institution.

	ABBREVIATIONS AND ACRONYMS	xix
	SUMMARY	1
1	INTRODUCTION	19
	Committee Charge and Approach,	21
	Study Framework,	24
	Genetically Engineered Traits in Crops,	28
	Adoption and Distribution of Genetically Engineered Crops,	30
	Deterrents to Genetically Engineered Trait Development in Other Crops,	47
	From Adoption to Impact,	50
	Conclusion,	52
	References,	52
2	ENVIRONMENTAL IMPACTS OF GENETICALLY ENGINEERED CROPS AT THE FARM LEVEL	59
	Environmental Impacts of Herbicide-Resistant Crops,	60
	Environmental Impacts of Insect-Resistant Crops,	83
	Gene Flow and Genetically Engineered Crops,	104
	Conclusions,	111
	References,	112

3	FARM-LEVEL ECONOMIC IMPACTS	135
	Economic Impacts on Adopters of Genetically Engineered Crops,	135
	Economic Impacts on Other Producers,	164
	Socioeconomic Impacts of Gene Flow,	169
	Conclusions,	174
	References,	175
4	FARM-SYSTEM DYNAMICS AND SOCIAL IMPACTS OF GENETIC ENGINEERING	187
	Social Impacts of On-Farm Technology Adoption,	188
	Social Networks and Adoption Decisions,	191
	Interaction of the Structure of the Seed Industry and Farmer Decisions,	192
	Social and Information Networks Between Farmers and Industry,	199
	Interaction of Legal and Social Issues Surrounding Genetic Engineering,	203
	Conclusions,	206
	References,	207
5	KEY FINDINGS, REMAINING CHALLENGES, AND FUTURE OPPORTUNITIES	213
	Key Findings,	214
	Remaining Challenges Facing Genetically Engineered Crops,	216
	Future Applications of Genetically Engineered Crops,	219
	Research Priorities Related to Genetically Engineered Crops,	227
	Advancing Potential Benefits of Genetically Engineered Crops by Strengthening Cooperation Between Public and Private Research and Development,	229
	References,	232
	APPENDIXES
A	Herbicide Selection	237
B	Tillage Systems	245
C	Biographical Sketches of Committee Members	247

List of Tables, Figures, and Boxes

TABLES

1-1	Percentage of Soybean Acres in Genetically Engineered Soybean Varieties, by State and United States, 2000–2009,	36
1-2	Insect Pests of Corn Targeted by Bt Varieties,	37
1-3	Percentage of Corn Acres in Genetically Engineered Corn Varieties, by State and United States, 2000–2009,	38
1-4	Insect Pests of Cotton Targeted by Bt Varieties,	42
1-5	Percentage of Cotton Acres in Genetically Engineered Upland Cotton Varieties, by State and United States, 2000–2009,	44
1-6	National Soybean Survey Descriptive Statistics by Adoption Category,	47
2-1	Weeds That Evolved Resistance to Glyphosate in Glyphosate-Resistant Crops in the United States,	74
2-2	Weeds Reported to Have Increased in Abundance in Glyphosate-Resistant Crops,	76
2-3	Regional Effects of Deployment of Bt Crops on Population Dynamics of Major Pests of Corn and Cotton,	88
3-1	Summary of Farm-Level Impact Evidence for Genetically Engineered Cotton in the United States, 1996–1999,	152
3-2	Fuel Consumption by Tillage System,	153
3-3	Value and Relative Importance of Nonpecuniary Benefits to Farmers,	156

3-4	Effect of Global Adoption of Genetically Engineered Crops on Commodity Prices,	160
3-5	Adoption of Genetically Engineered Crops and Their Distribution,	161
4-1	Estimated Seed Sales and Shares for Major Field Crops, United States, 1997,	195
4-2	Four-Firm Concentration Ratio in Field-Release Approvals from USDA Animal and Plant Health Inspection Service, by Crop, 1990–2000,	196

FIGURES

S-1	Application of herbicide to soybean and percentage of acres of herbicide-resistant soybean,	4
S-2	Application of herbicide to cotton and percentage of acres of herbicide-resistant cotton,	5
S-3	Application of herbicide to corn and percentage of herbicide-resistant corn,	6
S-4	Pounds of active ingredient of insecticide applied per planted acre and percent acres of Bt corn, respectively,	7
S-5	Pounds of active ingredient of insecticide applied per planted acre and percent acres of Bt cotton, respectively,	8
1-1	Genetically engineered crop adoption and impact framework,	28
1-2	Share of major crops in total pesticide expenditures, 1998–2007,	31
1-3	Nationwide acreage of genetically engineered soybean, corn, and cotton as a percentage of all acreage of these crops,	32
1-4	Herbicide-resistant soybean acreage trends nationwide,	36
1-5	Genetically engineered corn acreage trends nationwide,	40
1-6	Genetically engineered cotton acreage trends nationwide,	42
2-1	Application of herbicide to soybean and percentage of acres of herbicide-resistant soybean,	62
2-2	Application of herbicide to cotton and percentage of acres of herbicide-resistant cotton,	63
2-3	Application of herbicide to corn and percentage of herbicide-resistant corn,	64
2-4	Trends in conservation tillage practices and no-till for soybean, cotton, and corn, and adoption of herbicide-resistant crops since their introduction in 1996,	65

2-5	Soybean acreage under conventional tillage, conservation tillage, and no-till, 1997,	67
2-6	Number of weeds with evolved glyphosate resistance,	78
2-7	Pounds of active ingredient of insecticide applied per planted acre and percent acres of Bt corn,	84
2-8	Pounds of active ingredient of insecticide applied per planted acre and percent acres of Bt cotton,	85
2-9	Cumulative number of cotton pests evolving resistance to Bt cotton and DDT in the years after these management tools became widely used in the United States,	98
3-1	Seed-price index and overall index of prices paid by U.S. farmers,	147
3-2	Estimated average seed costs for U.S. farmers in real (inflation-adjusted) terms,	147
3-3	Real (inflation-adjusted) cotton seed prices paid by U.S. farmers, 2001–2007,	148
3-4	Real (inflation-adjusted) corn seed prices paid by U.S. farmers, 2001–2008,	148
3-5	Real (inflation-adjusted) soybean seed price paid by U.S. farmers, 2001-2008,	149
3-6	U.S. corn use,	165
3-7	U.S. soybean use,	165
4-1	Public and private research expenditures on plant breeding,	194
4-2	Share of planted acres of corn and soybean seeds by largest four firms (CR4),	195
4-3	Evolution of Pioneer Hi-Bred International, Inc./E.I. DuPont de Nemours and Company,	197
5-1	Number of permits for release of genetically engineered varieties approved by APHIS,	222
5-2	Approved field releases of plant varieties for testing purposes by trait (percent),	222

BOXES

S-1	Statement of Task,	2
1-1	Statement of Task,	22
1-2	Other Commercialized Genetically Engineered Crops,	33

2-1	Limitations to Evaluating the Magnitude of Environmental Effects,	61
3-1	Measuring Impacts,	136
5-1	New Traits Reduce Refuge Requirement and Introduce Second Mode of Herbicide Resistance,	219

Abbreviations and Acronyms

ACCase acetyl-CoA carboxylase

ALS acetolactate synthase

AMPA aminomethylphosphonic acid

APHIS Animal and Plant Health Inspection Service (U.S. Department of Agriculture)

BST bovine somatotropin

Bt Bacillus thuringiensis

Cry Crystal-like (protein)

DNA deoxyribonucleic acid

EIS environmental impact statement

EPA U.S. Environmental Protection Agency

EPSPS enzyme 5-enolpyruvyl-shikimate-3-phosphate synthase

GE genetically engineered

GMO genetically modified organism

HPPD hydroxyphenylpyruvate dioxygenase

HR herbicide-resistant

IPR intellectual-property rights

IR insect-resistant

ISHRW International Survey of Herbicide Resistant Weeds

MCL maximum contaminant level

NOP National Organic Program

NOSB National Organic Standards Board

OFPA Organic Foods Production Act

PTO U.S. Patent and Trademark Office

R&D research and development

USDA U.S. Department of Agriculture

USDA-ERS U.S. Department of Agriculture, Economic Research Service

USDA-NASS U.S. Department of Agriculture, National Agricultural Statistics Service

VR virus-resistant