An assessment of the vulnerability and adaptation potential of sugarcane production to water stress, southern Africa

• Published in: Journal of agriculture and food research Vol. 18; p. 101348
• Main Authors: Ngcobo, S., Jewitt, G., Hill, T.R., Archer, E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2024; Elsevier
• Subjects: Adaptation; Crop productivity ratio; Sugarcane production; Vulnerability; Water stress; Sugarcane production; Vulnerability; Water stress; Crop productivity ratio; Adaptation
• ISSN: 2666-1543; 2666-1543
• DOI: 10.1016/j.jafr.2024.101348

The high spatial variability of precipitation, heightened frequency of droughts and concomitant increases in exposure to water stress across southern Africa due to climate change, presents significant challenges for sugarcane production and the regional sugarcane production value chain. While production has intensified in the past few decades, yields have declined due to increased climatic variability and agronomic management approaches. Increased precipitation variability has enhanced sugarcane vulnerability to water stress and is likely to negatively affect yields. Combining crop simulations and relationships between sugarcane water use and observed rainfall, we introduce a crop productivity ratio (CPR) which assesses sugarcane water stress for six sugarcane mills across southern Africa. The CPR and simulation results were used to assess the adaptation potential or ‘space’ for mill areas that have varying rates of exposure and abilities to adapt to water stress. Simulation results were used to determine the long-term adaption potential of mill areas and to surmise the causes of yield declines. The results were used to offer recommendations to reduce vulnerabilities and enhance adaptation to water stress. We conclude that the amplification of inter-annual precipitation variability will enhance the exposure of sugarcane to water stress and require adaptation interventions. Adapting to external shocks is a multifaceted exercise that requires a holistic approach that includes every aspect of the sugarcane value chain. The following graphical abstract summarises the research content of this articleAll figures and images were produced by the authors. [Display omitted] •Sugarcane is vulnerable to water stress arising from amplified precipitation variability.•Sugarcane Mill Areas display variable abilities to respond to increased climatic variability.•We introduce a crop productivity ratio which assesses sugarcane water stress for sugarcane mills located across southern Africa.•Sugarcane yields are in decline due to the increased vulnerability of the sugar industry to climatic extremes and technological inequities.•Adaptation interventions have to be adopted as a matter of urgency to minimize vulnerabilities.