Climate Variability and Agricultural Adaptations in Northern Côte d'Ivoire: Restructuring Crop Calendars in the Korhogo Department (North of Côte d’Ivoire)
Oulai Jean-Gautier Kpan *
Department of Geosciences, Péléforo Gon Coulibaly University, Korhogo, Côte d'Ivoire.
Franck Maxime Gnamba
Department of Geosciences, Péléforo Gon Coulibaly University, Korhogo, Côte d'Ivoire.
Métangbo Diomandé
Department of Geosciences, Péléforo Gon Coulibaly University, Korhogo, Côte d'Ivoire.
Songoudaha Soro
Department of Geosciences, Péléforo Gon Coulibaly University, Korhogo, Côte d'Ivoire.
Yéi Marie Solange Oga
UFR Earth Sciences and Mining Resources, Félix Houphouet-Boigny University, Abidjan, Côte d'Ivoire.
*Author to whom correspondence should be addressed.
Abstract
Background: Seasonal rainfall variability affects crop timing in the Korhogo department of northern Côte d’Ivoire, where agriculture depends substantially on rainfall.
Objective: This study examined hydroclimatic variability during 1982–2022 and developed revised agricultural calendars for rice, maize, cotton and cashew.
Methods: Daily rainfall and temperature records from the Korhogo Airport station were examined alongside agronomic technical sheets. Annual variability was assessed with the Nicholson precipitation index and a second-order Hanning filter. Rainfall breakpoints were evaluated using Pettitt’s test and Hubert’s segmentation, while rainfall and dry-spell criteria were applied to identify seasonal onset and cessation. Crop operations were subsequently aligned with the identified seasonal pattern and crop-specific requirements.
Results: The analyses identified a major rainfall regime breakpoint in 2000 and a shift in the onset of the rainy season from April to May. Decadal mean rainfall declined to 1,179.4 mm during 2002–2011 before recovering to 1,505.595 mm during 2012–2021. The revised schedules placed upland rice sowing between May and mid-June, lowland rice between 15 June and 15 August, maize between 15 June and 15 July, and cotton between 20 May and 30 June. Cashew transplanting was scheduled for July–September.
Conclusion: The proposed calendars reflect the observed rainfall timing and may inform crop scheduling in Korhogo. Their suitability under farm conditions remains to be evaluated.
Keywords: Crop calendars, climate variability, rainfall disruption, crop production systems, Korhogo department