Growing Medium and Nutrient Solution Affect Performance of Ssamchoo and Romaine Lettuce Grown in Home Cultivation System

Abstract

The home hydroponic system used in this experiment supplied the nutrient solution using the ebb and flow-type system, and the supply time, interval, and water levels of the nutrient solutions were fixed. This experiment was conducted to find a more favorable growth medium for plant growth in the hydroponic system. The medium used in the experiment was of two types, phenolic foam and rockwool, and the heights were 28 and 38 mm, respectively. As for the the multipurpose nutrient solutions (GNU1 and GNU2) were prepared in the lab. The composition of the GNU1 and GNU2 was the same, and there was a difference between 100 and 70% in ion concentrations. The plants used were Ssamchoo (Brassica lee ssp. namai) and Romaine lettuce (Lactuca sativa L. var. longiflora). First, in the physicochemical measurements of the empty medium, change in the pH and EC of the distilled water passing through the medium was less in the rockwool than in the phenolic foam. This indicates that there is less change in the chemical properties of the nutrient solution due to the medium when rockwool is used. After hydroponic culture of Ssamchoo and Romaine lettuce, the medium showed more residual salts in Romaine lettuce. Both Ssamchoo and Romaine lettuce showed less salt accumulation in rockwool. The emergence rate was significantly higher in rockwool for both species. The lower height of the medium, the faster the emergence was. Ssamchoo displayed significantly higher fresh weight (124.7%), shoot length (107.6%), and leaf width (107.9%) when grown in GNU1, but there were no significant differences as affected by the medium. However, in Romaine lettuce, the type and height of the medium resulted in significant differences. The fresh weight of Romaine lettuce was significantly higher in rockwool (119.6%) than in phenolic foam, and significantly higher at 38 (114.6%) than 28 mm. Although there is a difference depending on the species, rockwool is more suitable for the ebb and flow-type system than phenolic foam, and the height of 38 is more advantageous than 28 mm.