Nutrient solution from growing lettuce using Nutrient Film Technique (NFT) was
drained from the substrate culture to grow Chinese kale in Dynamic Root Floating Technque
(DRFT) before the third usage for growing melon. The third re-used nutrient solution (UNS)
was drained from the melon growing substrate, diluted with tap water, and adjusted the
concentration to 2.0 mS/cm2, pH 5.8 before irrigation on the sweet corn field. Control plants
were grown under general management (manual watering and fertilizing with 15-15-15
fertilizer). Results indicated that growth parameters including shoot height, SPAD value and
fresh weight per plant using the third UNS were not significantly different from the control.
Yield parameters including number of ears, average weight per ear and average weight per
plant using the third UNS also showed no significant differences from the control. Water
consumption of sweet corn under treatment of the third UNS and the control were 35.55 and
108.23 L/plant, respectively resulted to reduced water consumption of up to 68.07% and no
fertilizer was used in the UNS treatment. Thus, the UNS method reduced both water and
fertilizer consumption, while minerals in the nutrient solution were completely utilized, leading
to cost reduction and environmentally friendly waste production.