EFFECTIVENESS OF EGYPTIAN PHOSPHATE ROCK ON CLOVER PRODUCTION IN ETHIOPIA

The majority of soils in Africa are phosphorus (P) deficient, but the high cost of water-soluble P fertilizers limits their use by resource- poor farmers. A low-cost alternative is to use phosphate rocks. We eva luated the effectiveness of Egyptian phosphate rock (EPR) relative to triple superphosphate (TSP) applied at 0, 15, 30, 45, and 60 kg P ha(- 1) to annual Trifolium species grown on a P-deficient Vertisol. The fe rtilizers were applied once and their effects were followed on seven c onsecutive annual clover crops. Clover responded to P at all the rates used. Significant (P<0.05) P effects on clover P content and DM yield s were observed up to the fourth crop. Over all the seven crops, EPR w as 89% as effective as TSP in increasing herbage DM and 93% as effecti ve in increasing herbage P content. Its substitution rates were 79% fo r DM yield and 86% for clover P content. Therefore, EPR was highly rea ctive and its use could elevate the P status of the P-deficient Vertis ols and increase feed and livestock productivity in the Ethiopian high lands.