Impacts of climate change on traditional irrigation farming systems and adaptation strategies in West Usambara Highlands, Tanzania

Abstract

Climate change is among the challenges to sustainable development due to its effects on major sectors of economy worldwide. However, its impacts differ from one system to another depending on the magnitude, vulnerability and adaptive capacity of the system. This study assessed the impacts of climate change on crop yields in Ndiwa and Chamazi traditional irrigation farming systems and their adaptation strategies. A cross-sectional research design was adopted employing purposive and systematic random sampling to select 380 respondents for this study. Data was collected through household survey, Focus Group Discussion, interviews, observation and documentary reviews. The results showed that, within 42 years (1981-2022), climate change has caused yield decline (maize, beans and irish-potatoes) by 12% to 51% and Maize being the most affected crop. The decrease in crop yield was linked to the decreased amount of water for irrigation and outbreak of crop diseases. Major adaptation strategies adopted as mitigation measures include cultivation closer to water sources (93.8%), early planting (86.9%), crop diversification (72.6%) and digging of shallow wells (58.7%). However, some adaptation strategies are detrimental to the environment. Adaptive capacity of farmers is low to medium. We recommend to improve adaptive capacity of farmers through access to climate information, financial resources, agricultural extension services and improved irrigation infrastructures.