Cotton (Gossypium hirsirtum L.) production under an organic crop rotation system and weather vagaries in the humid tropics

Climate change is an established challenge to global agricultural productivity. This two-year study evaluated the effects of five cropping systems on the agronomic performance of cotton in the humid tropics. Field trials were carried out during the late cropping seasons (July–December) of 2019 and 2020 on the Organic Research plot of the Institute of Food Security, Environmental Resources and Agricultural Research, Federal University of Agriculture, Abeokuta, Nigeria. Five cropping systems: continuous cropping without organic fertilizer (CS1), continuous cropping with organic fertilizer (CS2), crop rotation with organic fertilizer (CS3), crop rotation without organic fertilizer (CS4), and conventional cropping (CS5) were evaluated in a randomized complete block design and replicated three times. Sesame and soybeans were the preceding crops. The weather vagaries were described during the cropping seasons. In 2019, cotton plants under CS2, CS3, and CS4 produced significantly (p < 0.05) greater number of bolls per plant (24.3, 23.2, and 22.3), seed weight (16.0, 18.9, and 19.3 g), and greater seed yield (631.96, 675.08 and 677.88 kg/ha) than did cotton plants under CS1, respectively. A similar trend was recorded in 2020, except for the number of bolls per plant. Number of rainy days was 53 and 32 in 2019 and 2020, respectively. Prospective cotton growers in the region can adopt cotton production in rotation schemes that involve sesame and soybeans with (CS3) or without (CS4) the application of organic fertilizer and continuous application of organic fertilizer (CS2). A robust near real-time climate information service to aid farmers in their production activities is recommended.