Assessment of Indigenous Climate Change Adaptation Strategies and Its Impacts on Food Crop Yields in Osun State, Southwestern Nigeria

Abstract

This study investigated effects of indigenous climate change adaptation strategies on food crop yields in Osun State, southwestern Nigeria. It assessed changes in future climate (2031–2055) relative to the baseline period (1992–2016) and their impacts on the yields of 3 staple food crops (maize, rice and cassava). Robustness of the identified adaptation options adopted by local farmers was examined with a view to evaluating the opportunities of integrating indigenous adaptation options for climate-smart agriculture (CSA). A regional climate–crop modeling system (RegCM-DSSAT) and structured questionnaire were used for the study. A warmer and wetter future climate was projected with higher frequency of occurrence of false start of rainfall. Results also suggested future rise in the yield of cassava (8.2%) but declines in maize (− 9.2%) and rice (− 3.6%). Use of organic fertilizer, irrigation or fadama farming system and change in planting dates were ranked highly efficient indigenous adaptation strategies for improved crop yields. Model simulations projected 3.9% increase in cassava yield when irrigation farming system was adopted. This approach was found to offset the negative impact of future warming on the yields of maize and rice and increased their yields by 6.53% and 1.31%, respectively. Combined use of fertilizer and change in planting date was found to significantly enhance yields of maize (27.53%) and rice (21.49%). The paper concludes that integrated approach to indigenous climate change adaptation strategies, as required in CSA, could significantly reduce negative effects of future warming on food crop yields.