Enhancing production efficiency of tomatoes through soil moisture-dependent multifaceted responses in three-layered...

Climate issues globally highlight the need for efficient crop production. Therefore, Reliable water management for tomato cultivation is critical for conserving water use. Spain is one of the primary producers of tomatoes because of its three-layered soil composition showing higher moisture retention and lower water loss. This study employed a multilateral experimental approach to identify optimal irrigation region for enhancing water use efficiency (WUE) in tomato cultivation. Real-time soil moisture monitoring was implemented using 5 TE sensors to track volumetric water content (VWC) dynamically throughout the experiments. Upon water withholding in a pot experiment, tomato plants exhibited visible wilting and accumulated primary metabolites, such as proline, GABA, malic acid, citric acid, fructose, and glucose when the soil VWC dropped to 7.5 %. However, changes in leaf gas exchange and emissions of volatile organic compounds (VOCs), were observed before reaching this critical point. Notably, VOCs, caryophyllene and β-phellandrene, doubled as VWC decreased from 25 % to 15 %. This study uniquely combines real-time soil moisture monitoring with morpho-physiological-biochemical analyses to optimize irrigation in three-layered soil systems. These findings suggest that maintaining VWC between 25 % and 15 % not only conserves water but also supports plant health in TLS. Field validation confirmed that this strategy improved the efficiency of tomato production without negatively affecting plant growth, showing double IWUE (>60 kg/m³) compared to the previous method (30 kg/m³). This study proved that the use of VWC dynamics combined with multifaceted approaches enhanced the production of tomatoes under the low water availability and highlighted immediate practical strategies for addressing agricultural challenges under water-deficit conditions, particularly sustainable strategies for the improvement of crop productivity.