New Open Access Study on Water, Climate Change and the Citrus Industry

The authors of an insightful new paper, "Potential climate change impacts on citrus water requirement across major producing areas in the world", summarise the concepts of their research.

Some of the key questions that still remain lingering regarding climate change and its potential impacts on available freshwater resources across the globe are:

• How does an increase in atmospheric CO2 concentration (360, 490, 650, and 850 ppm) and associated changes in temperature affect citrus irrigation requirements?
• What are the effects of changes in temperature and precipitation on major water budget components across different geographic regions?
• Are there tradeoffs among the increase in CO2 concentration, crop water requirements and other water budget components?

This study was conducted to shed some light on these and other critical issues. The objectives of the study were to: i) calculate current citrus irrigation requirements, and ii) assess how potential climate change scenarios would affect citrus irrigation requirement and other water budget components, e.g., effective rainfall (ER), evapotranspiration (ETo), canopy interception (INT), drainage (DR), and runoff (RO) across the major producing regions in the world. The study covers the major citrus producing regions across the world: Africa (Cape Town, South Africa), Asia (Mersin, Turkey), Australia (Riverland, Australia), Mediterranean (Nabeul, Tunisia), North America (Riverside, California; Fort Pierce and Lake Alfred, Florida; and Brownsville, Texas), and South America (Sao Paulo, Brazil).

Some of the interesting findings of this study include:

• Current water footprint (IRR) of citrus show considerable variation across geographic locations.
• Increases in CO2 concentration will result in a significant reduction in citrus ET and IRR across all locations.
• Reduction in citrus ET could be up to 20-30% in the 2055s and 24-37% in the 2090s.
• Canopy interception and DR below citrus rootzones are expected to slightly increase in the future.
• Increase in temperature will lead to increase in ET and IRR, however, the effect of CO2 will be dominant resulting in a net decrease in ET and IRR.

Such information will help the citrus industry to make informed discussions regarding production and management strategies. However, further studies are needed to investigate how these predicted climatic and atmospheric changes will affect citrus yield and its economic impact on the citrus industry.

For more information, read the full OA paper in the Journal of Water and Climate Change free of charge.

Authors: Ali Fares, H.K. Bayabil, M. Zekri, D. Mattos-Jr and R. Awal.