Efficiency of available phosphorus in Cameroonian soils in the southern part of the country is low because of the low pH (‹ 5.5) which provokes high phosphorus fixation due to insoluble phosphate compounds formed with Fe, Mn and Al oxides and hydrous oxides. The present work was carried out to assess the effect of organic manure (Tithonia diversifolia (TD), Glyricidia sepium (GS), poultry manure (PM) and rabbit manure (RM) and inorganic P fertilizer (DAP) on agronomic variables of maize (Zea mays) and P efficiency fractions in three acidic soils of southern - Cameroon. This experiment was carried out by applying 10 g of dry matter of Tithonia diversifolia per kg of soil. The other amendments (GS, PM and RM) were applied to supply the same quantity of P content. DAP was added to supply 40 mg P2O5 / kg soil. The dry matter production, P concentration and P uptake over control, were significantly increased (P < 0.05) in maize shoot by the combination of organic and inorganic P amendments. Agronomic efficiency, physiological efficiency and P recovery of organic amendments of P, proved more efficient as compared to DAP. Results indicated that integration of organic amendments used with DAP was significantly better over the separate use of DAP. Nevertheless, P application in all the three soils, either separately or in combination, improved agronomic variables of maize and P uptake.
Keywords: Onana Adibimé Adalbert, Mvondo Ze Antoine David, Yerima Bernard Palmer, Noumbo Kenfack Séraphine, Tankou Mubeteneh Christopher.