The objective of the present study is to optimize seed cotton production by using ox dung in the BERE region of northwestern Côte d’Ivoire. The effect of ox dung was tested at a dose of 3000 kg/ha against 200 kg/ha of a mineral NPK fertilizer on cotton production. Two seeding methods regularly used by farmers were used in this study: flat seeding and seeding on ridges. The spacing of 80 cm x 30 cm with 2 plants per stake corresponding to the density of 83500 plants/ha were adopted. The experimental set-up consisted of completely randomized blocks with three replications. Observations were made on six agronomic parameters. Oxen dung increased the mass and yield of seed cotton by 19% compared to NPK, increasing their respective values from 3253.72 kg/ha for NPK and 3879.64 kg/ha for oxen dung. However, it induced low vegetative parameters of the cotton plants. The yield obtained with ridge seeding was higher than with flat seeding. The dung can therefore replace NPK fertilizer under the same growing conditions.

To assess the influence of Jatropha curcas cultivation on maize yield in a cropping association, a study was conducted on the application farm of the Ecole Régionale d'Agriculture du Sud in Bingerville from 2015 to 2016. The study aimed to determine the appropriate Jatropha planting density to improve maize yield in a cropping association. The experiment consisted in setting up a randomized complete block design with three replications, including three treatments T1 (2*2m); T2 (3*2m) and T3 (4*2m) based on the spacing of Jatropha curcas plants compared to a control T0 (control without jatropha). Morphological and yield parameters of Jatropha curcas and maize were assessed respectively. The results obtained show that the Jatropha-maize association had no significant effect (P > 0.05) on the agro-morphological parameters (growth, development and yield) of Jatropha curcas regardless of the treatment. On the other hand, a significant effect (P < 0.05) of the Jatropha-maize association was observed on plant biomass and maize yield, particularly with treatment T2. In conclusion, this experiment demonstrates that it is possible to harmoniously integrate regular row spacing (intercropping) in Jatropha curcas plantations during the juvenile period of the trees provided that the main crop (Jatropha curcas) is at a spacing of 3*2 m.