Shifting Cultivation in the Evergreen Forest of Southern Cameroon: Farming Systems and Soil Degradation Final report L. Nounamo and M. Yemefack Tropenbos-Cameroon1 Report 00-2 Shifting Cultivation in the Evergreen Forest of Southern Cameroon: Farming Systems and Soil Degradation 2 Shifting Cultivation in the Evergreen Forest of Southern Cameroon: Farming Systems and Soil Degradation Final Report L. Nounamo and M. Yemefack Tropenbos-Cameroon Reports 00-2 The Tropenbos-Cameroon Programme Kribi, Cameroon November 2000 3 © 2000 IRAD and the Tropenbos-Cameroon Programme No part of this publication may be reproduced in any form or by any means, or stored in a data base or retrieval system without the written permission of the copyright holders 4 PREFACE This report is the result of the study on shifting cultivation practices in the evergreen forest of southern Cameroon, carried out within the framework of ITTO Project PD 26/92, which is part of the Tropenbos- Cameroon Programme (TCP). TCP comprises fourteen interrelated sub-projects in the fields of ecology, forestry, economy, social science, agronomy and soil science. The main implementing agencies of the PD 26/92 Project are the “Institut de la Recherche Agricole pour le Développement (IRAD)”, “l’Office National de Développement des Forêts (ONADEF)”, the Tropenbos Foundation and Wageningen University. The authors wish to thank the General Managers of IRAD and ONADEF for selecting them to conduct this study. The present study was financed by the International Tropical Timber Organisation (ITTO), the Common Fund for Commodities (CfC), the Tropenbos Foundation and the main implementing agencies. The authors thank these organisations for making this study possible. We also wish to express our sincere gratitude to the TCP Team Leaders, Scientific Coordinators, colleague researchers and all the administrative and financial personnel for their support during the study. We sincerely thank all the students who contributed to the study through the development of their thesis. We think particularly of Nlome Ekongo Emmanuel, Nama Alexandre and Nguegang Asaa Prosper from the University of Dschang, and Obam Félix-Marcel and Meyomesse Ongolo Calvin from the University of Yaoundé I. Our special thanks go to Ndombou Jean, former Delegate of Agriculture for the Océan Subdivision, and his extension field staff for facilitating our introduction and contact in the villages of the TCP area. Finally, but very important, we are very grateful to all the farmers and field assistants of the villages in the TCP area with whom we studied the farming systems practices and soil degradation in a friendly and participatory manner. 5 Table of content PREFACE ........................................................................................................................................5 Table of content................................................................................................................................6 List of Tables....................................................................................................................................8 List of Figures ..................................................................................................................................9 1 INTRODUCTION.......................................................................................................................10 1.1 Background and justification ................................................................................................10 1.2 Objectives of the study..........................................................................................................10 1.3 The research area ..................................................................................................................10 2 METHODOLOGY......................................................................................................................13 2.1. Site selection ........................................................................................................................13 2.2 Methodology for farming systems study ..............................................................................13 2.2.1 Participatory approach....................................................................................................13 2.2.2 Exploratory survey .........................................................................................................14 2.2.3 Measurements of the size, expansion, crop density and yield of agricultural fields ......14 2.2.4 Farmers’ priority setting .................................................................................................15 2.2.5 Farmers’ strategies for soil fertility management...........................................................15 2.3 Methods for soil degradation study.......................................................................................15 2.3.1 Soil description and sampling.........................................................................................15 2.3.2 Laboratory soil analyses .................................................................................................16 2.3.3 Soil micro-variability study............................................................................................16 2.3.4 The agricultural activities in relation to the forest management ....................................16 2.3.5 Statistical data analyses ..................................................................................................16 3 FARMING SYSTEMS DESCRIPTION ....................................................................................17 3.1 Subsystems of the farms in the forest zone...........................................................................17 3.2 Characteristics of the physical environment.........................................................................20 3.2.1 Climate............................................................................................................................20 3.2.2 Vegetation.......................................................................................................................20 3.2.3 Landscape .......................................................................................................................21 3.2.4 Geology ..........................................................................................................................21 3.2.5 Soils ................................................................................................................................22 3.3 Socio-economic characteristics.............................................................................................22 3.3.1 Population.......................................................................................................................22 3.3.2 Infrastructure ..................................................................................................................22 3.3.3 Labour.............................................................................................................................23 3.3.4 Land and land tenure ......................................................................................................23 3.3.5 Farmers’ organisation and credit source.........................................................................23 3.3.6 Farm investment .............................................................................................................23 3.4 Cropping systems..................................................................................................................24 3.4.1 Cropping calendar...........................................................................................................24 3.4.2 Land Use Types..............................................................................................................24 3.4.3 Food Crop Fields ............................................................................................................24 3.4.3 Home garden...................................................................................................................28 3.4.4 Trees and perennial plantations ......................................................................................28 3.4.5 Fallow type .....................................................................................................................28 3.5 Trends in agricultural land expansion...................................................................................29 3.6 Animal system ..............................................................................................................6 ........31 3.6.1 Reared animals ...............................................................................................................31 3.6.2 Hunted animals...............................................................................................................31 3.7 Farmers’ agricultural production priorities...........................................................................32 3.7.1 Priority activities and land use types ..............................................................................32 3.7.3 Priority crops ..................................................................................................................32 3.7.4 Priority crop associations................................................................................................33