Short-term effect of the distance between the point of application of phosphate fertilizers (CBKCa and TSP) and the crown of the plant on the evolution of the fractions and the phosphorus balance of a Lixisol

The different fractions of phosphorus available in the short term were studied by the fractionation method. Soil samples (0-20 cm) were taken during 2021 and 2022 campaigns after the harvests in a test set up on the factorial design with four repetitions. The P sources (Calcined Burkina Phosphate enriched with calcium (CBKCa) and Triple Super Phosphate (TSP)) were applied to the main plots, and the subplots had three distances measured between the point of P fertilizer application and the plant crown (d0=0 d5=5 and d10=10 cm). The results showed that the fractions of inorganic P (Pi) (Pi-resin, Pi-NaHCO3, Pi-NaOH, and Pi-HCl) increased over time, both for the different P sources and for the different supply distances. Regarding P sources, no significant difference was noted by the ANOVA for all the fractions, except that of P linked to Calcium (Pi-HCl). Whatever the year and the source of the P, the d5 led to a reduction in all the fractions of between 7% in Pi-HCl and 234% in Pi-NaOH, compared to the d0. In addition, d5 obtained P content in grains and straw significantly higher than those of samples from d0 and d10. These results will help improve agricultural production. Key words: Soil acidity, Pi-HCl and Pi-NaOH fractions, Burkina Faso.