Soil moisture sensors have enabled continuous soil water status monitoring and became widely available to commercial growers. The use of soil moisture sensors that measure volumetric soil water content can be a useful tool to diminish or avoid over-irrigation addressing specific water requirements according to soil characteristics. However, the frequency of irrigation events, or a proper irrigation scheduling, using soil moisture sensor varies according to soil type, and the performance of soil moisture sensors as a tool to determine irrigation events on sandy soils used for organic vegetable production, particularly tomato, have not been evaluated up to date. Thus, the study objective was to evaluate the use of three irrigation scheduling strategies to enhance irrigation management in organic tomato production in the southeastern U.S. Field experiments were conducted on the organic unit at E.V. Smith Research and Extension Center from Auburn University, located in Shorter, AL in 2022 and 2023. Three irrigation scheduling treatments were tested: systematic irrigation (SYS), crop water demand (CWD), and soil water status method (SWS). In both years, results indicated that SWS had a higher biomass accumulation than CWD and SYS; consequently, tomato yield increased in the SWS compared to the two other treatments. Yield increments were 14% between SWS and CWD, and 25% between SWS and SYS. Irrigation water savings were also the highest for the SWS treatment, resulting in 72% water savings compared to SYS and 54% to CWD in 2022; while the SWS used 65% less water than SYS and 55% less than CWD in 2023. In general, rainfall events had an impact on strategies used to determine irrigation events. Among the studied irrigation scheduling methods, the SWS had a better performance in terms of fruit growth, biomass accumulation, and overall yield compared to CWD and SYS. Considering the global need for sustainable practices, the SWS treatment shows up as one of the best alternatives to the current grower standard practice, which consist in the SYS.
