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Sustainable management of soil resources in the humid tropics


Table of contents


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.

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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.

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Contents


Note to the Reader from the UNU

Summary

I. Introduction

A. Sustainability and soil quality
B. Sustainability and forest conversion
C. Attaining sustainability
D. Objectives

II. Humid tropics

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

1. Local effects
2. Regional and global effects

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 compatible

B. Components of a sustainable system

1. Nutrient management
2. Erosion management
3. Residue management
4. Crop management
5. Water management

C. Systems approach

V. Characteristics of an improved cropping/farming system

A. Land-use planning
B. Watershed management
C. Sustaining soil productivity

1. 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

A. Land-use capability
B. Land clearing and development

VII. Runoff management and erosion control

A. Preventive measures

1. Mulch farming
2. Conservation tillage
3. Strip cropping
4. Contour farming
5. Cover crops
6. Vegetative hedges or strips

B. control measures: engineering structures

1. Structures to prevent run-on
2. Structures to reduce runoff velocity
3. Structures to dissipate runoff energy

VIII. Nutrient management

A. Chemical fertilizers
B. Reducing nutrient losses

1. Soil erosion
2. Leaching
3. Volatilization losses

C. Biological nitrogen fixation (BNF)
D. Nutrient cycling

1. Crop residue mulch
2. Agroforestry systems

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:

References

Other titles of interest