Study of the agronomic performance of methanization digestate: the case of cucumbers

Soil Agricultural intensification in tropical regions faces significant challenges, including soil depletion and increasing reliance on chemical fertilizers, the environmental impacts of which are concerning. This study aims to assess the agronomic potential of methacompost, a solid residue derived from the anaerobic digestion of laying hen manure, as an alternative organic fertilizer for cucumber (Cucumis sativus L.) cultivation. A field experiment was conducted in the Gontougo region (Côte d’Ivoire), comparing seven methacompost formulations, an unfertilized control, and a reference treatment with NPK fertilizer (15-15-15). Physicochemical analyses revealed a high ammoniacal nitrogen content in all methacompost formulations. Agronomic results showed that the treatments MP75%, MP50%, MP25%, as well as the combination NPK50% + MP50%, resulted in vegetative growth and yields comparable to or exceeding those obtained with mineral fertilizer. These performances are attributed to the rapid mineralization of nutrients, ensuring their availability to plants. Economically, some methacompost formulations also demonstrated a lower cost per unit of fertilizer compared to NPK. This study confirms the potential of methacompost as a viable organic fertilizer for vegetable crops in tropical zones. It paves the way for the agronomic valorization of livestock waste in a circular and sustainable agricultural framework.