Abstract

Productivity in the food and cash crop production of small-scale farmers in southern Cameroon is in continuing decline as a consequence of worsening environmental factors, particularly land degradation. The first phase of this project established that the adaptation of exotic multipurpose trees to local conditions has a beneficial effect on soil productivity. This second phase will continue to develop ways of overcoming difficulties related to the introduction of soil improving shrub species, such as Cajanus cajan, before these methods are introduced in the practice of small-scale farming. It will also provide degree and in-service training, and establish a strong research team of local scientists capable of pursuing research in a well equipped agroforestry unit. It will further continue the evaluation of improved management regimes in tree-crop systems; screen local multipurpose tree species; and design, test, and disseminate appropriate systems and technologies.

Post-Project Summary

The project continued with the monitoring and evaluation of on-going trials, and initiated new studies. Two experiments were conducted to assess the potential of various multipurpose trees in soil fertility maintenance and to determine mulch plus fertilizer requirement for optimum crop yield. Among the tree species studied in these trials, Cassia siamea, Calliandra calothyrsus, Leucaena leucocephala, and Gliricidia sepium had good potential for soil fertility improvements when used on non-acid soils. Cassia siamea was the highest biomass producer; however, Calliandra calothyrsus mulch appeared to be of higher quality and improved crop yield comparable to that of Cassia mulch application. The potential of hedgerow intercropping appeared to be crop specific, i.e. suitable for cereals but not necessarily for legume crops, or root and tubers. Modification of the conventional hedgerow intercropping management with the application of moderate levels of inorganic fertilizer was necessary to maintain production. It was recommended that all hedgerow intercropping trials be modified to integrate a fallow phase. Support continued in a third phase (001325/94-0010).

Recipient Institution(s)