FrontMatter -- Preface -- Acknowledgments -- Contents -- Executive Summary -- Summary -- 1 Understanding Agricultural Sustainability -- 2 A Pivotal Time in Agriculture -- 3 Improving Productivity and Environmental Sustainability in U.S. Farming Systems -- 4 Economic and Social Dimensions of the Sustainability of Farming Practices and Approaches -- 5 Examples of Farming System Types for Improving Sustainability -- 6 Drivers and Constraints Affecting the Transition to Sustainable Farming Practices -- 7 Illustrative Case Studies -- 8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States -- 9 Conclusions and Recommendations -- Appendixes -- Appendix A: Statement of Task -- Appendix B: Biographical Sketches -- Appendix C: Presentations to the Committee on 21st Century Systems Agriculture -- Appendix D: Follow-up of the 1989 Case Studies Featured in Alternative Agriculture Report: Topics of Discussion During Telephone Interview -- Appendix E: Dairy Farms: Topics of Discussion During On-Farm Interview -- Appendix F: Grain Farms: Topics of Discussion During On-Farm Interview -- Appendix G: Specialty-Crop Farms: Topics of Discussion During On-Farm Interview.