Optimal Water Use for Crops and Irrigation Planning in a Changing Climate

Jim Crocker
28th May, 2024

Optimal Water Use for Crops and Irrigation Planning in a Changing Climate

Image Source: Natural Science News, 2024

Key Findings

  • The study in the Lower Kulfo Catchment of southern Ethiopia found that crops will need more water in the future due to higher temperatures and altered precipitation patterns
  • Average reference evapotranspiration is projected to increase by 11.9% for 2030-2050 and by 16.2% for 2060-2080 compared to 2010-2022
  • Farmers will need to irrigate more frequently, with irrigation intervals shortening from 8 days to 7 days and 5 days in future scenarios
Understanding the future of agriculture in Ethiopia under climate change is crucial for ensuring food security and sustainable farming practices. Recent research conducted by Arba Minch University[1] delves into how climate change will affect crop water requirements, irrigation scheduling, and optimal land allocation in the Lower Kulfo Catchment of southern Ethiopia. The study addresses a significant challenge: the lack of assessment of crop water needs and irrigation schedules under future climate scenarios. Using advanced climate models and hydrological tools, the researchers projected changes in temperature and precipitation. They then employed the Crop Water Assessment Tool to estimate future crop water requirements and developed optimal land allocation strategies using the General Algebraic Modeling System. The findings indicate that average reference evapotranspiration—a measure of water loss from soil and plants—increased by 11.9% for the period 2030-2050 and by 16.2% for 2060-2080 compared to the baseline period of 2010-2022. This suggests that crops will need more water in the future due to higher temperatures and altered precipitation patterns. Correspondingly, total seasonal crop water requirements were projected to rise from 4,529 mm in the baseline period to 4,866.7 mm for 2030-2050 and 5,272.2 mm for 2060-2080. The study also found that irrigation intervals would shorten, from an average of 8 days in the baseline period to 7 days and 5 days in the future scenarios. This means that farmers will need to irrigate their crops more frequently to meet the increased water demand. The required irrigation water at the main canal inlet is expected to rise by 6.8% for 2030-2050 and by 18% for 2060-2080. To optimize land use, the researchers proposed two scenarios. Scenario 1, which uses non-negativity constraints, suggests allocating 60.4% of the land to tomatoes, 20.8% to maize, and 18.8% to watermelons, yielding a net benefit of 1.47*10^8 Ethiopian Birr. Scenario 2, based on farmer adaptation practices, allocates 48% to maize, 31.6% to tomatoes, and 20.4% to watermelons, resulting in a slightly lower net benefit of 1.34*10^8 Ethiopian Birr. This reduction in net benefit highlights the trade-offs between maximizing economic returns and ensuring food security. The implications of this study are profound. It provides a roadmap for policymakers to promote climate-resilient agriculture and underscores the importance of educating small-scale farmers through workshops and training. This aligns with previous studies that emphasize the need for improved water management and efficient irrigation techniques in arid and semi-arid regions[2][3]. For instance, adopting water-saving irrigation methods and selecting drought-resistant crop varieties have proven effective in enhancing crop productivity under water-scarce conditions[2]. Moreover, the study's focus on optimal land allocation is crucial for balancing economic gains with food security. It resonates with findings from other research that highlight the benefits of diverse cropping systems and integrated land management practices[4]. By adopting these strategies, Ethiopian farmers can better cope with the adverse effects of climate change, ensuring sustainable agricultural production and livelihoods. In summary, the research conducted by Arba Minch University provides valuable insights into the future of crop water requirements and irrigation scheduling under climate change. It offers practical solutions for optimizing land use and enhancing the resilience of small-scale farmers, contributing to the broader goal of sustainable and climate-resilient agriculture in Ethiopia.



Main Study

1) Crop water requirement and irrigation scheduling under climate change scenario, and optimal cropland allocation in lower kulfo catchment.

Published 30th May, 2024 (future Journal edition)


Related Studies

2) Assessment of soil mulching field management, and deficit irrigation effect on productivity of watermelon varieties, and AquaCrop model validation.


3) Effect of furrow irrigation systems and irrigation levels on maize agronomy and water use efficiency in Arba Minch, Southern, Ethiopia.


4) Impact of climate change on agriculture and adaptation strategies in Ethiopia: A meta-analysis.


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