Design and performance assessment of a PLC based automation system for controlled environment multi-layer hydroponic horticulture

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Horticulture factory farms, having controlled environment hydroponic setups used to produce fresh and nutritious vegetative near consumption areas, serve as transformative solution to food security challenges. Manual control in such farms leads to variability and human error, restricting repeatable precision and ultimately compromising yield and sustainability. To address this, PLC based automation solution is proposed in this work. A novel architecture incorporating network of sensor and actuator, is specifically designed for multilayer hydroponic farms. Based on proposed design, a functional prototype was developed in laboratory, with precise control over light intensity, temperature, humidity, nutrient flow, pH, and EC. The effectiveness of the automation and prototype is monitored by growing various leafy horticultural plants, under different treatments. Among the several experiments performed, detailed statistical growth analyses of Basil (Ocimum basilicum) is recorded and compared with other studies. The result demonstrated that the plant height and biomass remained within the ranges, while leaf count showed a noticeable increase compared against manually controlled farms. Autonomously varying control parameter and its effect on plant growth was also evaluated by varying light intensities across different sections of the prototype. The assessed high F-values in ANOVA for leaves count (63.75), buds (90.70), leaf length (16.92) and plant height (7.73) confirms the significant differences on the growth. Result showcase designed system’s ability to handle multiple treatments simultaneously in a single prototype, which is extremely challenging under manual operation. Technical robustness and sustainability of proposed automation is evaluated by comparing the specifications with similar automation systems, clearly indicating PLC automation is more preferred for factory farm environment. The presented automation design contributes toward Agriculture 4.0 for sustainable food production and supports UN Sustainable Development Goal 2 (Zero Hunger), ensuring safe and nutritious food for current and future generations.