FAO FERTILIZER AND PLANT NUTRITION BULLETIN 15 Scaling soil nutrient balances Enabling mesolevel applications for African realities
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 2004
	Table of Contents

Cover photographs:

Hedgerow intercropping, Ghana. FAO/18309/P. Cenini.
Coffee field, Kenya. E. Smaling.

Copies of FAO publications can be requested from:

SALES AND MARKETING GROUP
Information Division
Food and Agriculture Organization of the United Nations
Viale delle Terme di Caracalla
00100 Rome, Italy

E-mail: [email protected]
Fax: (+39) 06 57053360
Web site: http://www.fao.org

The designations employed and the presentation of material in this information product 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 or delopment status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

ISBN 92-5-105237-9
ISSN 0259-2495

All rights reserved. Reproduction and dissemination of material in this information product for educational or other non-commercial purposes are authorized without any prior written permission from the copyright holders provided the source is fully acknowledged. Reproduction of material in this information product for resale or other commercial purposes is prohibited without written permission of the copyright holders.
Applications for such permission should be addressed to:
Chief
Publishing Management Service
Information Division
FAO
Viale delle Terme di Caracalla, 00100 Rome, Italy
or by e-mail to:
[email protected]

© FAO 2004

Contents

Foreword

Acknowledgements

Preface

Acronyms

Glossary

Chapter 1. Introduction

Rationale
The nutrient balance model
Objective
Structure

Chapter 2. Study area descriptions

Country and study area selection
Ghana

Cocoa-based farming system
Economic importance

Kenya

The tea - coffee - dairy farming system

Mali

The cotton-based farming system

Chapter 3. Methods

Macrolevel

Land-use map
Model parameters
Fallow

Mesolevel

General procedure
Ghana
Kenya
Mali

Microlevel

Overview

Calculation of soil nutrient stocks

Chapter 4. Results

Macrolevel
Ghana
Kenya
Mali
Mesolevel

Cocoa-based farming system in Ghana
Tea - coffee - dairy - based farming system in Kenya
Cotton-based farming system in Mali

Microlevel

Farms in Embu District, Kenya
Villages in Mali-Sud, Mali

Chapter 5. Discussion

A comparison of macrolevel methodologies: 1990 and 2003
Comparing macro - meso and micro - meso levels
Comparing the mesolevel between countries
Data problems

Macrolevel
Mesolevel
Microlevel

Modelling problems

Land-use map
Erosion modelling
Nutrient-balance calculations

Shortcomings and caveats

Validation
Gaps
Specific problems for each scale level
Presentation of outcomes
Usefulness for policy-makers

Impact

Bibliography

Annexes

Annex 1. Nutrient content values of manure from literature
Annex 2. Reference values for K-leaching regression model
Annex 3. Rooting depth
Annex 4. Reference values for gaseous losses
Annex 5. A procedure for LAPSUS modelling
Annex 6. Soil properties - FAO74 classification
Annex 7. Data used for macrolevel nutrient balances in a 2003 FAO study on Ghana, Kenya and Mali
Annex 8. Results of the macrolevel nutrient-balance calculations from a 2003 FAO study of Ghana, Kenya and Mali
Annex 9. Data used for mesolevel nutrient balances from a 2003 FAO study of Ghana, Kenya and Mali
Annex 10. Results of the mesolevel nutrient balance calculations from a 2003 FAO study of Ghana, Kenya and Mali
Annex 11. Abstracts of presentations from a 2003 workshop in Nairobi on scaling soil nutrient balances

FAO technical papers

Back cover