The sustainability of agriculture, including the land, the natural resources and the people is of concern throughout the world. Nowhere is the sustainability issue of more immediate importance than in the Tropics, where population pressures, a fragile environment and the need for foreign currency combine to put incredible pressures on the natural resources. To protect these resources and maintain the capacity of these lands to produce food and fiber requires that we know why these trends are occurring and how they can be prevented or reversed.
The American Society of Agronomy has a significant membership in tropical countries. The Society thus was most pleased to be able to support symposia on the topic of sustainable agriculture in the Tropics and to publish this book. The publication represents the assessment of many international experts in soils, crops and agronomy of the Tropics. This will be a valuable reference to the literature and an outstanding reference text for those who wish to develop and promote the technologies that will help sustain this critical resource—the Tropics.
D.R. KEENEY, president, American Society of Agronomy
C.W. STUBER, president, Crop Science Society of America
D.W. NELSON, president Soil Science Society of America
Land and its associated natural resources provide our basic needs and is the source of most of the world's accumulated wealth. Agronomists and ecologists share a special responsibility for helping maintain the natural resource base because they understand why these resources are rapidly deteriorating and have the technical knowledge necessary to reverse negative trends.
In 1990, the American Society of Agronomy appointed a workgroup to find ways of better serving its growing international membership. Because sustainable agriculture was at that time an emerging and internationally recognized concept, the workgroup sought and gained approval to prepare a publication on the subject, not only for the membership of the Society, but also for the larger scientific community. The material for the publication Technologies for Sustainable Agriculture in the Tropics was accumulated from two symposia convened by the International Division (A-6) of the American Society of Agronomy in 1990 and 1991. The tropical region was chosen because its lands are more easily degraded than perhaps any other part of the inhabited world and population pressures there are the most intense. In addition to the introductory and concluding chapters prepared by the editors, all multiauthor contributions are organized in seven parts. Part I, has two chapters, the first by H. Eswaran et al., examines the constraints, challenges, and choices facing the establishment of sustainable agriculture in developing countries, with the greatest emphasis on the quality of soil resources in the Tropics. In the second chapter, J. Ragland argues that agricultural sustainability is a task for all humanity, consumers and farmers alike, and that once the development process begins it must be managed to produce substantial wealth. Otherwise, the natural resources will continue to be degraded indefinitely to satisfy basic needs.
Part II also contains two chapters and is entitled “Technological Options.” The first chapter, by P.A. Sanchez, presents convincing arguments and strong evidence that modern agronomic technologies can be linked with indigenous farming traditions to provide systems which are both high yielding and sustainable. In the second chapter D.P. Garrity assesses the state of knowledge in developing sustainable systems for the extensive sloping uplands of Southeast Asia, and the ways in which the pathway of land degradation in this ecosystem may be reversed.
The three chapters in Part III are concerned with agroforestry and nutrient cycling. These chapters provide valuable information on the use of woody and herbaceous species in building sustainable agriculture production systems but, at the same time, show that more research and interpretation of existing research will be required to resolve conflicting results form alley cropping and agroforestry experiments. The paper by D.P. Garrity in Part II should also be read in connection with the chapters in Part III.
Part IV contains one chapter on erosion management by J.W. Smyle and W.B. Magrath. It is a thorough review of Vetiver grass, which is one of the most useful plants available for the control of soil erosion in the tropics. Part V of the book also contains only one chapter, which presents the status of crop and crop-soil computer models and their integration into decision-support systems for sustainable agriculture. The argument is advanced and examples are given of how modern computer technology will play an increasingly major role in developing and gaining the adoption of sustainable agriculture systems. Such approaches are promising shortcuts to finding sustainable agriculture systems.
Part VI consists of three chapters which develop the socioeconomic aspects of sustainability, which must be fully integrated with the biophysical elements. This part is entitled “Macroscale Influences.”
Part VII consists of six chapters and deals with the incredibly complicated and difficult problems of sub-Saharan Africa (SSA). The first chapter by A. Kesseba is a comprehensive review of the socioeconomic and political aspects of agricultural sustainability in SSA. It enumerates strategies for developing a viable and sustainable agricultural sector in SSA. The following three chapters by B.N. Okigbo, R. Lal and P. Vlek are comments on strategies outlined by A. Kesseba and critique pros and cons of available options. In the fifth chapter R. Lal summarizes technological options for agronomic management of soil and water resources of different agroecoregions of SSA. The last chapter of this section by V. Balasubramarian and Nguimgo K.A. Blaise presents two case studies on the importance of improved follows on sustaining agronomic productivity.
The concluding summary by the editors is an attempt to indicate knowledge gaps and prioritize research and development needs for achieving agricultural sustainability.
Taken as a whole, the chapters are an excellent report on the status of agronomic research and scholarship pertaining to sustainable agriculture-particularly of the Tropics. At the same time, the book makes no pretense of being a manual for producing sustainable agriculture systems throughout the Tropics. The resources and political will to achieve such systems will exist only when the public demands them. Hopefully, this book will hasten the coming of that day by revealing what is possible for one of the world's most problem-ridden regions—the Tropics.
JOHN RAGLAND, chair
University of Kentucky Lexington, Kentucky
RATTAN LAL, cochair
The Ohio State University, Columbus, Ohio
A. N. Atta-Krah, Agroforester, International Institute of Tropical Agriculture, P.M.B. 5320, Ibadan, Nigeria
V. Balasubramanian, Senior Maize Agronomist, International Institute of Tropical Agriculture, IRA/NCRE Project, B.P. 2067, Yaounde, Cameroon
Nguimgo K. A. Blaise, Agronomist, Institut de Recherche Agronomique, B.P. 2067, Yaounde, Cameroon
W. G. Boggess, Professor, Department of Food and Resource Economics, University of Florida, P.O. Box 110240, Gainesville, FL 32611-0240
W. T. Bowen, Scientist, International Fertilizer Development Center, P. O. Box 2040, Muscle Shoals, AL 35662
Kenneth Cassman, Division Head, Agronomist, Division of Agronomy, Plant Physiology, and Agroecology, International Rice Research Institute, P. O. Box 933, Manila 1099, Philippines
C. B. Davey, Professor Emeritus, Department of Forestry, North Carolina State University, Raleigh, NC 27695-8008
H. Eswaran, National Leader, USDA-SCS, P. O. Box 2890, Washington, DC 20013
Erick C. M. Fernandes, Visiting Assistant Professor, North Carolina State University, Tropical Soils Research-Brazil, EMBRAPA-CPAA, Manaus, AM 69.001, Brazil
Charles A. Francis, Professor, Department of Agronomy, University of Nebraska, 279 Plant Science, Lincoln, NE 68583-0910
Dennis P. Garrity, Systems Agronomist and Coordinator, Southeast Asian Regional Research Programme, International Centre for Research in Agroforestry, P.O. Box 161, Bogor, Indonesia
Peter E. Hildebrand, Professor, Department of Food and Resource Economics, University of Florida, 2126 McCarty Hall, Gainesville, FL 32611-0240
James W. Jones, Professor, Agricultural Engineering Department, University of Florida, Gainesville, FL 32611
Jagmohan Joshi, Director, Soybean Research Institute, University of Maryland- Eastern Shore, Princess Anne, MD 21853
Anthony S. Juo, Professor, Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843
B. T. Kang, Soil Scientist, International Institute of Tropical Agriculture, Oyo Road, P.M.B. 5320, Ibadan, Nigeria
Abbas M. Kesseba, Director, International Fund for Agricultural Development, Technical Advisory Division, Via Del Serafico, 107, Rome 00142, Italy
Clyde F. Kiker, Professor of Resource Economics, Food and Resource Economics Department, University of Florida, McCarty Hall, Gainesville, FL 32611-0240
Rattan Lal, Professor of Soil Science, Department of Agronomy, The Ohio State University, 2021 Coffey Road, Columbus, OH 43210
W. B. Magrath, Natural Resources Economist, The World Bank, 1818 H Street NW, Washington, DC 20034
Richard Morris, Professor, Department of Soil Science, Oregon State University, Corvallis, OR 97331
Uzo Mokwunye, Director, International Fertilizer Development Center, Agro-Economic Division, P. O. Box 2040, Muscle Shoals, AL 35660
S. K. Mughogho, Associate Professor, Crop Science Department, Bunda College of Agriculture, University of Malawi, P.O. Box 219, Lilongwe, Malawi
L. A. Nelson, Professor Emeritus, Department of Statistics, North Carolina State University, Box 8203, Raleigh, NC 27695-8203
Bede N. Okigbo, Director, United Nations University Programme on Natural Resources in Africa, c/o UNESCO/ROSTA, P.O. Box 30592, Nairobi, Kenya
John Ragland, Professor of Agronomy, Agronomy Department, University of Kentucky, Agriculture Science Building-North, Lexington, KY 40546
J. T. Ritchie, Professor, Homer Nowlin Chair, Department of Crop and Soil Sciences, Michigan State University, A570 Plant and Soil Sciences Building, East Lansing, MI 48824
P. A. Sanchez, Director General, International Center for Research in Agroforestry, P. O. Box 30677, Nairobi, Kenya
J. W. Smyle, Land Resources Management Specialist, The World Bank, 1818 H Street NW, Washington, DC 20034
L. D. Spivey, Jr., Soil Scientist, USDA-SCS, P. O. Box 2890, Washington, DC 20013
Walter W. Stroup, Professor of Biometry, Department of Biometry, University of Nebraska, 103 Miller Hall, Lincoln, NE 68583-0712
S. M. Virmani, Agroclimatologist, International Crops Research Institute for the Semiarid Tropics, Patancheru P.O., Hyderabad, Andhra Pradesh, India
Paul L. G. Vlek, Professor, Institute of Agronomy in the Tropics, Georg-August University, Goettingen, Germany
Ray R. Weil, Professor of Soil Science, Agronomy Department, University of Maryland, HJ. Patterson Hall, College Park, MD 20742