Abstract

In West Africa, use of local phosphate rock for crop fertilization has declined in recent years from previous low levels. Instead, imported processed phosphate fertilizers are employed. High world prices and transport costs make these too costly for small farmers. Phase I of this project sought to identify efficient phosphate fertilizers, agronomically and socio-economically appropriate to Mali, developed from indigenous phosphate deposits. Researchers in phase II will complete measurements of residual phosphate availability and agronomic effectiveness of local phosphate sources in continuing on-station trials; develop a preliminary model for phosphate responses; develop phosphate fertilizer recommendations for principal crops; and, conduct an extended program of farm trials.

Post-Project Summary

This project developed on-farm trials based on the results of experimental station research done in phase I. The trials were to assess fertilizer sources and rates under farmers' usual crop management practices, and to evaluate economic return from the use of different phosphate fertilizers and management practices. The trials took place in areas with variable soil and weather conditions, and were maintained for three years to allow for evaluation of crop yield variation, management practices; residual effects of Tilemsi phosphate rock (TPR); and farmer economic returns. Sixty farmers were also interviewed about alternative fertilizer sources appropriate to farmers' conditions in selected cropping systems. It was observed that farmers' decisions for using chemical fertilizers largely depended on the expected crop response and the chances of obtaining it. Researchers concluded that TPR was a suitable alternative phosphate fertilizer source for use in cash and food cropping systems in Mali, especially in those areas with low production levels from low soil fertility.

Recipient Institution(s)