Evaluation of the Effectiveness of a Biodegradable Organic Fertilizer Based on Neem (<i>Azadirachta</i><i> i</i><i>ndica</i>) ‘BioNeem+’ on the Agronomic Performance of Amaranth (<i>Amaran

Problem Statement: Despite their importance for vegetable production, liquid organic fertilizers remain underutilized, even though they offer an alternative to the high cost of mineral fertilizers on the market. Amaranth cultivation in Benin is carried out with the use of synthetic fertilizers, resulting in harmful consequences for soil quality and public health. Methodology: This research aims to evaluate the effectiveness of a liquid organic fertilizer made from Neem (Azadirachta indica) on the agronomic performance of amaranth (Amaranthus cruentus) grown in the commune of Abomey-Calavi. To conduct this research, a Fisher block design was set up at the experimental station with four (04) treatments and three (03) replications, corresponding to twelve (12) plot units, each with an area of 2 m2. The treatments applied were: T0: Absolute control (no fertilizer input); T1: Plants treated with a dose of 10% in 90% of water; T2: Plants treated with a dose of 20% in 80% of water; T3: Plants treated with a dose of 30 in 70% of water. Data collected on growth parameters (number of leaves, height, collar diameter) and yield at the first and second harvests were subjected to Poisson linear regression analysis and ANOVA using R software. Results: The results of this study showed that the treatments receiving liquid organic fertilizer were the most effective across all parameters considered (number of leaves, height, collar diameter, and fresh weight yield). The best results were obtained with treatment T2, with 20% of liquid organic fertilizer.