Optimization of Nutrient Solution Concentration and Substrate Selection for Hydroponic Basil Cultivation

Hydroponic cultivation is gaining importance as a sustainable and efficient method for crop production under controlled environmental conditions. The present study was conducted to standardize nutrient solution concentration for different growing substrates in hydroponic basil cultivation under a naturally ventilated polyhouse at Dr. NTR College of Agricultural Engineering, Bapatla, Andhra Pradesh. The experiment consisted of four nutrient concentrations, viz., 900 ppm, 1000 ppm, 1100 ppm and 1200 ppm, and four growing media, namely rockwool, clay balls, perlite and vermiculite. The experiment was carried out during four different seasons to evaluate the interaction effect of nutrient concentration and growing media on sweet basil (Ocimum basilicum) yield. Statistical optimization and analysis were performed using Design-Expert employing a split-plot multilevel categorical factor design. Analysis of variance (ANOVA) indicated that nutrient concentration, growing media and their interaction significantly influenced basil yield (p< 0.05). The developed regression models showed high coefficients of determination (R² > 0.87), indicating good model adequacy and prediction accuracy. The results revealed that 1100 ppm nutrient concentration produced superior yield compared to other concentrations across seasons. Vermiculite performed better during summer conditions, whereas rockwool and clay balls showed improved performance during cooler seasons due to better aeration and moisture balance. The optimization study demonstrated that suitable nutrient concentration combined with appropriate growing media significantly enhanced sweet basil productivity in hydroponic systems. The study concluded that 1100 ppm nutrient concentration with suitable substrate selection can be recommended for maximizing basil yield under protected hydroponic cultivation.