Technological Features of Smart Periodic Flooding Modules in Protected Vegetable Growing

Purpose. To investigate the technological parameters of ebb-and-flow smart modules under protected-soil conditions for growing leafy and fruiting vegetable crops; to determine optimal flooding cycle regimes; to evaluate the effectiveness of IoT integration for monitoring and automated management of cultivation processes; and to establish comparative resource-efficiency indicators relative to competing hydroponic production technologies. Methods. Field experiments growing butterhead lettuce (Lactuca sativa L.), basil (Ocimum basilicum L.), and tomatoes (Solanum lycopersicum L.) in ebb-and-flow smart modules of 40–120 L capacity with automated management through an IoT sensor network (pH, EC, temperature, humidity, illuminance). Yield accounting, water and electrical energy consumption measurements, and flooding cycle timing were performed using standard methodologies. Statistical data processing was carried out by one-way analysis of variance (ANOVA) with means comparison by LSD at P ≤ 0.05. Results. The optimal flooding regime for leafy crops was established as 4–6 cycles per day, 15–20 minutes each, with a nutrient-solution depth of 6–8 cm in the tray. For fruiting crops, 3–4 cycles of 20–25 minutes were optimal. Water consumption in the studied system for butterhead lettuce was 8 ± 0.6 L/kg yield compared with 250 L/kg in soil cultivation (96.8% savings). Lettuce yield in ebb-and-flow systems with full IoT automation (pH 5.8–6.2; EC 1.4–1.8 mS/cm; photoperiod 16 h) exceeded the control (manual management) by 22.4%, averaging 4.8 kg/m² per 28-day cycle. Full-spectrum LED lighting (efficiency 2.7 μmol/J) reduced lighting energy consumption by 74% compared with high-pressure sodium (HPS) lamps. Mobile-application integration reduced system maintenance time by 65–70% and improved the precision of nutrient-solution parameter maintenance. Discussion. The results are consistent with data reported by Barbosa et al. (2015) on manifold reductions in water consumption in hydroponic systems relative to soil cultivation, and with conclusions of Graamans et al. (2018) on the value of LED optimisation in closed systems. The advantage of ebb-and-flow over deep-water culture (DWC) systems for fruiting crops is confirmed by superior oxygen supply to the root zone due to alternation of moisture and aeration phases. Compared with nutrient-film technique (NFT) systems, ebb-and-flow modules demonstrated greater flexibility when changing the crop assortment and lower dependency on continuous pump operation. Conclusions. Smart ebb-and-flow modules with full IoT integration provide demonstrably higher yields of leafy vegetables (by 22%) and more efficient water use (by 96%) compared with conventional technologies. Automated flood-drain regime management via mobile applications is a key factor for process stability and system accessibility for producers without specialised training. A promising direction is the integration of machine vision for non-contact plant-status monitoring and predictive management of flooding cycles.