Response of interspecific and sativa upland rices to Mali phosphate rock and soluble phosphate fertilizerKKoneauthorOSylvesterauthorEDiattaauthorSSomadoauthorKValereauthorK LSahrawatauthorIn West Africa, two-thirds of upland rice is grown on acidic phosphorus (P)- deficient soils. Phosphorus is one of the most limiting-nutrients affecting crop productivity. A three-year field experiment was conducted on a Ferralsol in Coˆ te d’Ivoire to study the response of four interspecific rice cultivars and a sativa (control cultivar) to Tilemsi phosphate rock (PR) and soluble triple superphosphate (TSP) fertilizer. PR was applied at 0, 150, 300, and 450 kg ha71 P once in the first year and residual effects were measured in the following years. TSP (0, 50, 100 and 150 kg ha71 P) was applied yearly. More significant yield increasing (38%) was observed in the second year. Annual application of 50 kg P ha71 as TSP or a one-time application of 150 kg P ha71 as PR was the optimum rate for the production of all cultivars. Higher rates of P from TSP (100 and 150 kg P ha71) gave 2–3 times greater residual P in soil than the optimum rate, inducing no further response of rice. Two interspecific cultivars were identified as the most acid- and low P-tolerant cultivars for improving rice production in West Africa humid forest zone.Soil Science2011Taylor & FrancisArticle