Abstract:
Climate change is estimated to exacerbate existing challenges faced by smallholder farmers
in Sub-Sahara Africa. However, limited studies quantify the extent of variation in climate change
impact under these systems at the local scale. The Decision Support System for Agro-technological
Transfer (DSSAT) was used to quantify variation in climate change impacts on maize yield under
current agricultural practices in semi-arid regions of Senegal (Nioro du Rip) and Ghana (Navrongo
and Tamale). Multi-benchmark climate models (Mid-Century, 2040–2069 for two Representative
Concentration Pathways, RCP4.5 and RCP8.5), and multiple soil and management information from
agronomic surveys were used as input for DSSAT. The average impact of climate scenarios on grain
yield among farms ranged between ��9% and ��39% across sites. Substantial variation in climate
response exists across farms in the same farming zone with relative standard deviations from 8%
to 117% at Nioro du Rip, 13% to 64% in Navrongo and 9% to 37% in Tamale across climate models.
Variations in fertilizer application, planting dates and soil types explained the variation in the impact
among farms. This study provides insight into the complexities of the impact of climate scenarios on
maize yield and the need for better representation of heterogeneous farming systems for optimized
outcomes in adaptation and resilience planning in smallholder systems.
