Static versus stage‐specific soil water tension thresholds for peanut irrigation in Southwest Georgia

Abstract Irrigation scheduling for peanut ( Arachis hypogaea L.) in Georgia increasingly relies on soil moisture sensing, but it remains unclear whether stage‐specific soil water tension (SWT) thresholds improve on a season‐long static threshold. From 2020 through 2025, a randomized complete block split‐plot field experiment was conducted at the University of Georgia Stripling Irrigation Research Park near Camilla, GA, using a variable‐rate lateral irrigation system. Two runner‐type cultivars were planted as split‐plot strips; preliminary cultivar analysis showed no significant cultivar effect for yield, and yield‐derived responses were summarized at the whole‐plot irrigation‐schedule level. Eight irrigated SWT schedules were compared with a rainfed control, with thresholds changed at 40 and 110 days after planting. Thresholds represented wet (W), optimal (O), and dry (D) soil conditions at 20, 45, and 70 kPa, respectively. Because field position rotated with year, treatment effects were evaluated within year, and across‐year treatment statements are descriptive. Rainfall‐dominant seasons often limited realized separation among SWT schedules. The static O/O/O (45/45/45‐kPa) benchmark was never statistically lower than the highest‐yielding irrigated treatment within a year. The D/O/O (70/45/45‐kPa) schedule remained statistically similar to O/O/O, but it reduced early‐season threshold‐driven irrigation relative to O/O/O only in 2020 and 2024; therefore, it should be interpreted as a conditional alternative rather than a replacement for the benchmark. The D/W/O (70/20/45‐kPa) schedule was often among the most heavily irrigated schedules and, in benchmark‐focused planned contrasts, was lower than O/O/O for yield and adjusted revenue in 2021 and for irrigation water use efficiency (IWUE) in 2025. Across yield, IWUE, and adjusted revenue, the static O/O/O schedule was the best‐supported baseline under these Southwest Georgia Coastal Plain conditions. These results support retaining 45 kPa as the default Watermark‐based trigger while treating stage‐specific schedules as conditional options rather than universal replacements.