AquaCrop Modeling for Sustainable Potato Irrigation: Trade-offs between Yield and Crop Water Productivity

Abraham RaiNawab AliYounsuk Dong^*

• Michigan State University, East Lansing, United States

Potato is an important staple food crop for global food security, its productivity is sensitive to water availability, making precision irrigation management crucial for optimum yield, and Crop Water Productivity (𝑊𝑃 𝐶 .. AuuaCrop model was calibrated and validated under 50% and 70% Field Capacity (FC. managed through SoilWatch-10 moisture sensors at 15-, 30-, and 45-cm depth.Thereafter, different irrigation scenarios, -20% to 90% FC, -were developed and simulated across 10 years (2014-2024.; classified as wet (>312.90 mm., normal (2560-312.90 mm. and dry (<2560 mm. years based on total crop growth season rainfall, for yield and 𝑊𝑃 𝐶 across the two soil types.Trade-off analyses were performed for all scenarios across all years-normal, wet, and dry years-to assess the relationship between yield and 𝑊𝑃 𝐶 , simulating yield effectively with Index of Agreement (IA. of 0.999; with results indicating that simulated yield at harvest closely matched the observed yield (10%., suggesting significant accuracy of model. Soil water content estimations under both treatments were satisfactory with IA and Nash-Sutcliffe model Efficiency coefficient (NSE. close to 1. Scenario analysis exhibited variation for yield and 𝑊𝑃 𝐶 for irrigation treatments across soil types. Trade-off analysis showed that irrigation at 40 % to 60% of FC resulted in better yield and 𝑊𝑃 𝐶 , as categorized in the win-win scenarios, across all years and two different soil characteristics. Similarly, correlation analysis revealed that the mid-tuber to latetuber bulk stages were critical for irrigation supplement corroborated by the findings of 40% to 70% FC irrigation scenarios. As such, AuuaCrop could be a feasible modeling tool to optimize irrigation for potato yield and 𝑊𝑃 𝐶 under climate variability.