Assessment of the Vulnerability of Smallholder Maize Production to the Adverse Effects of Climate Change in Southern Nyanza Region, Kenya

Abstract

Vulnerability assessment is critical towards helping policy makers understand and quantify the impacts and consequences of climate change. Therefore, this study sought to assess the vulnerability of smallholder maize production to adverse climate change impacts in Southern Nyanza region. The study data included historical climate data for the period 1983-2016 for temperature, and 1988-2018 for rainfall obtained from CHIRTS and CHIRPS daily data respectively. Time periods for temperature and rainfall data were different since CHIRTS data was only available from 1983-2016. Climate projections for the period 2022-2051 was done using data extracted from CORDEX Africa family of models under RCP4.5 and RCP8.5 emission scenarios. Socioeconomic and biophysical data were sourced from the Ministry of Agriculture, Livestock, Fisheries and Cooperatives, Tegemeo Institute of Agricultural Policy and Development, Kenya National Bureau of Statistics, and Kenya Institute for Public Policy Research and Analysis. The trends and mean shifts of baseline rainfall and temperature were statistically significant as depicted by the p-values of Man-Kendall and Pettit’s tests that were smaller than the significance level value (α= 0.05). Similarly, all the projections showed a general decreasing trend in rainfall, with an increasing significant trend in maximum and minimum temperatures. The results of the correlation analysis indicated that there was a significant relationship between maize yields and climate variables (maximum and minimum temperature, and rainfall) across the various stages of growth of maize. The vulnerability indices for the study counties were driven mainly by maize productivity, infrastructural, and socioeconomic development levels. Migori County recorded the highest vulnerability (0.72), followed by Homabay County (0.48), Kisii County (-0.29), and Nyamira County (-0.74). Smallholder maize production in Southern Nyanza region was generally vulnerable to climate change owing to the significant increase in temperature. These trends are expected to persist into the future, thus increasing the vulnerability of smallholder maize production in Southern Nyanza region. The findings of this study will go a long way in helping smallholder farmers identify relevant adaptation strategies to help them reduce the vulnerability of maize production to adverse climate change effects. The findings of this study will also assist agricultural extension officers and other relevant stakeholders in identifying the most vulnerable counties to adverse climate change effects, and enable them make recommendations that would support the implementation of appropriate climate change policies to cushion smallholder maize production systems against adverse climate change effects in order to achieve sustainable maize productivity and food security