Abstract
Soil acidification is a major constraint in cotton-based cropping systems, as it reduces both the efficiency of mineral fertilizers and cotton productivity. In this context, the present study aimed to evaluate the agronomic effectiveness of Polifol foliar fertilizers enriched with calcium and/or magnesium as an alternative or complementary approach to conventional cotton fertilization in Côte d'Ivoire. A field trial was conducted at the Centre National de Recherche Agronomique (CNRA) in Bouaké, using a randomized complete block design with five treatments and four replicates. The effects of the different fertilizer formulations were assessed on the basis of plant height, plant density, number of nodes per plant, taproot depth, and seed cotton yield, and compared with the recommended fertilization treatment (200 kg ha⁻¹ of NPK 15-15-15 + 6S + 1B and 50 kg ha⁻¹ of urea).
The results showed that Polifol treatments significantly improved plant height, root development, and seed cotton yield. Plant height ranged from 102.8 to 130.6 cm, taproot depth from 18.88 to 21.97 cm, and seed cotton yield from 1 061 to 1,262 kg ha⁻¹. The best performances were obtained with treatments T3 and T5, with T5 producing the tallest plants (130.6 cm) and T3 the highest seed cotton yield (1,262 kg ha⁻¹). In contrast, Polifol application did not significantly improve plant density or the number of nodes per plant. The experimental soil was strongly acidic (pH = 5.0), with a low organic matter content (2.27%) and a low exchangeable base content (1.953 cmol+ kg⁻¹). These first-year results demonstrate the agronomic potential of Polifol formulations to improve cotton productivity and offer promising prospects for more sustainable soil fertility management in cotton-based cropping systems.