Evaluation of Crop Water Stress Index for Irrigation Scheduling in Peanut Production in Alabama

Abstract

Precision irrigation management in peanut (Arachis hypogaea L.) production can help farmers conserve water resources, reduce production costs, and maximize yield and quality. An experiment was conducted to evaluate three CWSI computation approaches (Empirical (CWSI-E), Theoretical (CWSI-T), and Integrated (iCWSI) for irrigation scheduling in two growing seasons (2024 & 2025) in Geneva County, Alabama. Among the approaches, CWSI-Theoretical demonstrated superior performance, with the strongest response to daily changes in soil water content and significant negative correlations under the 66% deficit (r = -0.336) and fully irrigated (r = -0.269) treatments, while CWSI-E and iCWSI were less sensitive. The findings showed that within-field variability in soil texture, Soil ECa, and topography influences peanut crop water use and stress response, making this field an ideal candidate for VRI to enable more precise irrigation management, ensure efficient water use, maximize yield and quality, and conserve water resources.