Effect of Organic/Inorganic-Cation Balanced Fertilizers on Yield and Temporal Nutrient Allocation of Tomato Fruits under Andosol Soil Conditions in Sub-Saharan Africa

International audienceThe impact of organic fertilizers on plant behaviour under andosol conditions is not well understood. A field experiment was conducted on a silty and slightly acidic andosol, very poor in phosphorous (3 mg kg- 1of soil) and potassium (0.13 meq/100g of soil), with an imbalance Ca:Mg:K ratio of 74.0:25.0:0.7. The effect of integrated mineral fertilization (using N, P, K, Ca and Mg), dry poultry manure (organic), the association of the two (organo-mineral) fertilizers and non-integrated mineral fertilization has been studied on yield and nutrient allocation of two varieties of tomato (Solanum lycopersicum L. var. Roma VF and Tima). Yields of red tomatoes from organo-mineral fertilized plants (39.27-34.38 t ha-1) werethree times higher than the yields from plants fertilized with non-integrated minerals (12.97-11.59 t ha-1).Allocation of macronutrients (P, K and Ca) was high in fruits from plants fertilized with organic, organomineraland integrated mineral fertilizers. Fruit calcium increased mostly at the fruit ripening stage, while phosphorus and potassium accumulated mainly before the fruit ripening stage. This trend was by far more pronounced under organo-mineral and organic fertilization. Overall, the kinetics of nutrient allocation indicate a clear positive impact of poultry manure and organo-mineral fertilizers in improving tomato production on andosol