Trends of seasonal climate variability on maize production in the Zambezi Region, Namibia: Projection from 1945/1946 to 2023/2024

Climate change has emerged as a significant challenge in Southern Africa, with indicators such as increased temperature variability, prolonged droughts, and erratic rainfall patterns profoundly affecting agricultural productivity. Climate variability, intensified by global warming, is anticipated to exacerbate the frequency and severity of extreme weather events, including flooding, drought, and sea-level rise. The objective of this study was to determine the impact of seasonal climate variability on maize (Zea mays L.) production in the Zambezi Region, Namibia over the period of 1945/1946 to 2023/2024. Over 79 seasons, only approximately 36.7% of the seasons received rainfall amounts (>650 mm) was considered reliable for optimal maize production. Rainfall analysis revealed that 57% of the seasons fell below 650 mm, indicating significant vulnerability for maize production in the country. Temperature trends showed a notable increase after the 2009/2010 season, contributing to higher evapotranspiration rates and escalating crop water demand. Simulations using the CROPWAT model demonstrated that maize yields were highly sensitive to planting dates and moisture availability, with optimised planting schedules significantly mitigating yield losses. Trends in maize crop water requirements, effective rainfall, and yields were closely aligned, emphasising the crucial role of stored soil moisture. Significant seasonal variations in temperature, rainfall, relative humidity, and sunshine were observed and are projected to persist, highlighting their ongoing influence on maize productivity. Overall, the study underscores the necessity of adaptive strategies to sustain maize production under increasing climatic uncertainty in the Zambezi region.