Sustainable management of soil resources in
the humid tropics This is the old United Nations University website. Visit the new site at http://unu.edu
Sustainable management of soil resources in
the humid tropics
By RATTAN LAL
The United Nations University is an organ of the United Nations established by the General Assembly in 1972 to be an international community of scholars engaged in research, advanced training, and the dissemination of knowledge related to the pressing global problems of human survival, development, and welfare. Its activities focus mainly on peace and conflict resolution, development in a changing world. and science and technology in relation to human welfare. The University operates through a worldwide network of research and postgraduate training centres, with its planning and coordinating headquarters in Tokyo.
The United Nations University Press, the publishing division of the UNU, publishes scholarly books and periodicals in the social sciences, humanities, and pure and applied natural sciences related to the University's research.
United Nations University Press
TOKYO • NEW YORK • PARIS
© The United Nations University, 1995
The views expressed in this publication are those of the author and do not necessarily reflect the views of tile United Nations University.
United Nations University Press
The United Nations University.
53-70. Jingumae 5-chome,
Shibuya-ku, Tokyo 150, Japan
Tel: (03) 3499-2811
Telex: J25442
Fax: (03) 3406-7345
Cable: UNATUNIV TOKYO
Produced by Emilia, Inc., Tokyo
Printed by Permanent Typesetting and Printing Co.. Ltd., Hong
Kong
UNUP-876
ISBN 92-808-0876-1
03500 P
Note to the Reader from the UNU
A. Sustainability and soil quality
B. Sustainability and forest conversion
C. Attaining sustainability
D. Objectives
A. Climate
B. Vegetation
C. Soils
D. Predominant farming systems
E. Soil degradation in the humid tropics
III. TRF in the humid tropics and its conversion
A. Forest conversion
B. Effects of forest conversion
IV. Basic concepts of sustainable land use in the humid tropics
A. Requirements of a sustainable improved agricultural system
1. High energy flux
2. Less drudgery and more dignity
3. Effective water management
4. Soil restorative
5. Ecologically compatibleB. Components of a sustainable system
1. Nutrient management
2. Erosion management
3. Residue management
4. Crop management
5. Water management
V. Characteristics of an improved cropping/farming system
A. Land-use planning
B. Watershed management
C. Sustaining soil productivity1. Bringing new land under cultivation
2. Managing existing lands and restoring the productivity of degraded lands
VI. Techniques for forest conversion and new land development
VII. Runoff management and erosion control
1. Mulch farming
2. Conservation tillage
3. Strip cropping
4. Contour farming
5. Cover crops
6. Vegetative hedges or stripsB. control measures: engineering structures
1. Structures to prevent run-on
2. Structures to reduce runoff velocity
3. Structures to dissipate runoff energy
A. Chemical fertilizers
B. Reducing nutrient lossesC. Biological nitrogen fixation (BNF)
D. Nutrient cycling
IX. Ecological approach to sustainable land use in the humid tropics
A. Soil erosion control
B. Soil organic matter maintenance
C. Soil structure
D. High soil biodiversity
E. Mineral cycling
F. Soil resilience
G. Ecological compatibility
X. Research and development priorities
A. Understanding the processes and mechanisms responsible for:
B. Developing new and innovative management systems for:
C. Transferring technologies already known through:
D. Developing the predictive capacity for extrapolating results from one region to another by:
E. Developing appropriate indicators of sustainability by: