Efficacité agronomique des phosphates naturels du Burkina Faso sur le riz pluvial en sol ferralitique

Résumé

A comparative experiment on the agronomic efficiency of Burkina Faso rock phosphate (BP) and triple superphosphate (TSP) on upland rice crops was conducted in 1988 and 1989 in oxisols, using a randomized Fisher block design with four different phosphate input levels (0, 13, 26 and 39 kg/ha/year). Mineral nutrients absorbed by rice plants and rice yield were evaluated. Results showed that P deficiency is a limiting factor for upland rice production (Table 1). Application of TSP or BP increased P absorption (Table 3) and rice yield (Table2). Rice uptake of P was better with TSP, probably because of its solubility, while BP also increased Zn and Al uptake (Table 2). In 1988, the two phosphates had the same agronomic efficiency on rice yield (Table 2), while BP more efficiently increased rice yield than TSP in 1989 (Table 2). BP seems well adapted and economically suitable for upland rice fertilization.