Effets de la fertilisation potassique des sols ferrugineux tropicaux sur la nutrition minérale et la productivité du cotonnier ( Gossypium hirsutum L.) au Burkina Faso

Abstract

To evaluate potassium fertilization effects on the cotton yield and fiber quality characteristics, two years study was conducted on two experimental stations, located in West and East Burkina Faso. Treatments were five rates of potassium chloride (0; 25; 50; 75 and 100 kg ha-1 KCl) associated to the recommended mineral fertilizer (150 kg ha-1 of 14-18-18-6S-1B + 50 kg ha-1 urea) of cotton. The treatments were arranged in a randomized block design. The cotton plant nutrition, yields and its components and fiber characteristics were evaluated. The cotton plant K nutrition at 70 days after emergence and cotton-seed yields were significantly improved by applied rates of potassium compared to the control. KCl application rates of 75 and 100 kg ha -1 were statistically equivalent to 50 kg ha -1 which gave a surplus cotton-seed production of 139 kg ha-1 and 214 kg ha-1, respectively in Kouaré and Farako-bâ. Compared to the control without KCl, potassium didn’t have significant effects on bolls production, fiber yield and quality, and seed index. Despite the use of recommended mineral fertilization rate, the soil K balance was negative. Potassium application reduces the K deficits and ensures positive soil K balance. Use of KCl at 50 kg ha-1 with the recommended mineral fertilizer could be done to improve cotton yield and soil K balance.