Sustainable dryland cropping in relation to soil productivity - FAO soils bulletin 72













Table of Contents


C.J. Pearson
The University of Queensland
Gatton, Australia

D.W. Norman
Kansas State University
Manhattan, Kansas, USA

J. Dixon
FARM Programme
FAO Regional Office for Asia and the Pacific
Bangkok, Thailand

FAO SOILS BULLETIN 72

Food and Agriculture Organization of the United Nations

The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

M-53
ISBN 92-5-103792-2

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior permission of the copyright owner. Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed to the Director, Publications Division, Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalla, 00100 Rome, Italy.

© FAO 1995

This electronic document has been scanned using optical character recognition (OCR) software and careful manual recorrection. Even if the quality of digitalisation is high, the FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed version.


Table of Contents


Foreword

Acknowledgements

Chapter 1 - Properties of dryland cropping systems

What is a cropping system?
Evolution of field crop ecosystems

Extensification
Intensification

Drylands
Soils

Chapter 2 - Physical aspects of crop productivity

Interrelationships of soil resources and cropping systems
Soil pores and water characteristics
Soil fabric, density and strength
Soil structure and crop growth
How management directly affects soil structure
Field indicators of physical problems
Management for maintenance of soil physical properties

Chapter 3 - Biological and chemical aspects of soil productivity

Soil biology and the biological micro-environment
Organic matter
Soil organisms associated with the crop

Bacteria and nitrogen
Fungi, algae and nutrients

Weeds, crop pests and diseases
Inorganic nutrition
Field indicators of biological and nutritional problems
Management for maintenance of soil biology and nutrition

Chapter 4 - Sustainable crop rotations

African examples

Key resource issues for sustainability in Africa

Asian examples
Australian and mediterranean examples
Rotations and soil productivity

Chapter 5 - Summary of physical, biological and management aspects of dryland cropping

Lessons for dryland cropping systems

Need to import nutrients
Need for realistic pricing to encourage better crop and management choices
Participation by farmers and their responsibility for land care
Measurement of cropping sustainability
Desirability of matching biological solutions to local circumstances
Appropriate soil management and the use of fallows
Need for more legume crops
Weeds, pests and diseases as indicators of management expertise

The balance of future research and development

Chapter 6 - Social and economic issues

Factors influencing farming systems

Households in the SATs
Communities in the SATs
Effects of support services and policies
Land
Labour

Household composition
Total labour inputs
Seasonality

Capital and cash
Cropping patterns
Interactions between crops and livestock

Animals as a source of power

Other factors influencing farming systems

Strategies to achieve sustainability

Background - Policies and institutions
Role of livestock
Productivity with sustainability
Agricultural productivity
Ecological sustainability
Need for a coordinated approach

Preventive measures
Corrective measures
Policy measures

Conclusions

References

Glossary