Growth and Yield of Lettuce (Lactuca sativa L.) Using the Deep Flow Technique (DFT) System with Different Growing Media

Hydroponic systems generally use rockwool as a growing medium. Growing media such as husk charcoal, cocopeat, and sawdust are agricultural waste that can be utilized as planting media for hydroponic cultivation, in terms of growing media that are easily available and widely available. This study aimed to evaluate the effects of different growing media on the growth and yield of lettuce cultivated using the Deep Flow Technique (DFT) hydroponic system and to identify suitable alternatives to rockwool. The experiment was conducted in Sempaja Selatan from June to July 2023 using a single-factor Randomized Complete Block Design (RCBD) with four treatments: rockwool, rice husk charcoal, cocopeat, and sawdust. Each treatment was replicated four times, with a total of 40 plants per treatment (10 plants per replication). Data were analyzed using analysis of variance (ANOVA) followed by Duncan’s Multiple Range Test at the 5% significance level. The ANOVA results showed significantly different among the growing media on plant height, number of leaves, fresh weight, and dry weight, but no significant differences in stem diameter and leaf area. Sawdust produced the highest plant height (10.55 cm) and number of leaves (25.60 leaves per plant), while cocopeat resulted in the highest leaf area (1,226.36 cm²), fresh weight (148.15 g), and dry weight (10.53 g). Rice husk charcoal produced the largest stem diameter (11.70 mm). These findings indicate that alternative growing media can support lettuce cultivation in DFT hydroponic systems, although their suitability depends on the growth variable considered. Their affordability and availability make them potential alternatives to rockwool, particularly for household-scale cultivation