Soil Moisture Content Suitability for Coffee Growing under Climate Change Scenarios in Uganda

Abstract

Background: Previous studies have looked at suitability of Arabica coffee with less emphasis on Robusta coffee. Secondly, they looked at coffee suitability in terms of temperature and rainfall. Methods: This study examined the effect of climate change on soil moisture content for coffee growing in Uganda, using historical (1990-2022) and projected (2025-2050) data from Terraclimate and eight Global Climate Models (GCMs). Soil moisture was analyzed in relation to coffee crop moisture thresholds at the root zone to simulate historical and future coffee suitability under two scenarios: Shared Socio-economic Pathways (SSPs) 245 and 585. Results: Soil moisture content in Uganda was characterized by high variability in highland areas during the March to May season among years. Furthermore, there were both decreasing and increasing trends averaging at ±1mm/Month. The future was on the other hand dominated by increasing trends over the western region and eastern-northern regions under SSP245 and SSP585 respectively averaging at 0.2mm/Month. Suitability analysis for 1990-2022 revealed that 71% of Uganda was highly suitable for coffee, while future predictions indicated an increase in suitable areas to 74% under SSP245 and 81% under SSP585. Conclusion: Generally, the higher moisture content associated with climate change will result in increased suitability of coffee by 10%, however, characterized by shifting area suitability especially for the mid-northern and south western regions where a reduction and gain in suitability is expected, respectively. This study highly the importance of identification and adaptation of site-specific soil moisture conservation practices, especially in the unsuitable areas.