Abstract

Southern Cameroon, lying within the humid lowlands of the tropics, is facing a general, steady environmental degradation characteristic of developing countries. Productivity of small-scale farmers, both in terms of cash and food crops, is on the decline. Considering the predominance of resource-poor farmers and the very fragile nature of tropical soils, the agroforestry approach of incorporating woody perennials (trees and shrubs) into existing farming systems constitutes a sound practice, given the potential of trees to build up organic matter and buffer soil acidity. Previous phases allowed the identification of local and exotic multipurpose trees (MPTs) that have clear potential in improving and maintaining soil productivity. More information and fine-tuning are, however, required on appropriate crop combinations and economic returns from these technologies before embarking on full-scale extension. This phase III will continue support for the International Centre for Research in Agroforestry (ICRAF) and the Institute of Agronomic Research (IRA) to jointly undertake research with the primary objective of refining and/or developing new agroforestry technologies for adoption by small farmers aimed at improving soil fertility and hence crop production. Continued degree and in-service training will enhance IRA's in-house capability to conduct relevant agroforestry research.

Post-Project Summary

Previous phases were funded under projects 89-0151 and 91-0199. Most of the project's efforts were geared toward monitoring and evaluation of ongoing and new on-station and on-farm trials aimed at developing technologies for soil fertility management. Field activities were undertaken to characterize home gardens; investigate smallholder resource management strategies on rainforest margins; establish gene banks of multipurpose trees (Irvingia, Prunus africana), evaluate the performance of various provenances of Calliandra on acid soils; identify efficient fallow management techniques based on Leucaena leucocephala and Gliricidia sepium; assess the effect of one-year fallow on Cajanus cajan and Sesbania pachycarpa on crop yield and soil properties; evaluate rotational hedgerows on-farm; identify key socioeconomic characteristics likely to influence the adoption of rotational hedgerows; test the effect of various residue management techniques on soil fertility and crop yield; and assess the effect of shrub (C. cajan and S. pachycarpa) and crop (maize and groundnut) density on shrub establishment, crop yield and soil properties. Two doctoral candidates completed their fieldwork as part of the project, on home gardens and smallholder resource management strategies, respectively. One BSc student from the University of Dschang carried out his special project on the effect of soil type and Rhizobium inoculation on early growth of Calliandra calothyrsus. A professor from the same university studied vegetative propagation of 15 Calliandra provenances. Five students from the technical school of agriculture and the school of forestry participated in various aspects of the on-station and on-farm trials. In December 1995, the project team organized a regional workshop on agroforestry research and development in the humid lowlands of West Africa. Participants from eight African and two European countries participated, and a total of 45 papers were presented. The workshop resulted in the formation of an Expert Task Force on Agroforestry for West and Central Africa.

Recipient Institution(s)