Although the majority of soils in Africa are P deficient, the high cost of
conventional water-soluble P fertilizers limits their use by resource-poor
farmers. Rockphosphates are a low-cost alternative. The effect of Egyptian
rockphosphate (ERP) from two sources, applied at 50 kg P ha(-1) on annual T
rifolium tembense (clover) grown on a Vertisol was evaluated. The fertilize
rs were applied once and their effects were followed on five consecutive an
nual clover crops. Clover responded to P from either source of ERP, with no
significant difference between the two sources. Significant (P < 0.05) P e
ffects on clover P uptake and dry matter yields were observed up to the thi
rd crop. The effect of mixing TSP with ERP on yields of Desmodium sanduicau
se was also evaluated on an Alfisol. Mixtures containing 1:1 and 1:3 ratios
of TSP:ERP on the basis of P content, gave the highest yields, but these w
ere not significantly higher than those from ERP applied alone. Therefore,
mixing ERP with the more expensive TSP is not justified. Use of rockphospha
tes alone could elevate the P status of the P-deficient soils and increase
forage and livestock productivity in the Ethiopian highlands.