OPTIMIZATION OF LETTUCE GROWTH THROUGH SUBSTRATE AND NUTRIENT COMBINATIONS IN HYDROPONICS

This study investigates the effects of different growing substrates and nutrient treatments on the vegetative growth and average leaf weight of Lactuca sativa (lettuce) cultivated in a hydroponic system. Four substrates—vermiculite, perlite, coconut coir, and rockwool—were evaluated in combination with three nutrient regimes: mineral salts alone, mineral salts with humic acid, and mineral salts with microalgae. The results reveal that the inclusion of humic acid and microalgae significantly enhanced plant performance, with the highest average leaf weight observed in the rockwool + mineral salts + microalgae treatment (31.233 g). Rockwool outperformed other substrates due to its superior water retention and aeration properties. Microalgae supplementation contributed the most notable improvement, likely due to its bioactive compounds and nutrient-enhancing effects. These findings emphasize the importance of optimizing both substrate and nutrient combinations to improve lettuce yield in soilless cultivation systems.