Designing, fabrication and evaluation of a small-scale vertical hydroponic system to produce leafy vegetables

The agricultural productivity in Newfoundland and Labrador (NL) faces many challenges, including severe weather conditions, short growing seasons, and poor soil conditions. To address these challenges in NL, researchers should explore innovative methods like hydroponic farming to improve local food production. This study was conducted to design, fabricate, and evaluate a household hydroponic system capable of producing year-round leafy vegetables. A vertical hydroponic system was designed, fabricated and tested along with two other systems including 1) a vertical drip hydroponic system (G-DNA), 2) a vertical wick hydroponic system (C-Tree), and 3) a horizontal deep water culture (DWC) system as the control, under two growth conditions (a grow tent experiment and an experiment without a grow tent). The growth of spinach, water use efficiency (WUE) and nitrogen use efficiency (NUE) in three systems were tested. Results showed that the G-DNA system produced significantly higher spinach yield and outperformed the C-Tree hydroponic system. While G-DNA and C-Tree hydroponic systems had no significant effect on WUE, compared to the DWC system which demonstrated nearly twice the WUE. The G-DNA system exhibited the highest NUE in both environmental conditions, suggesting that spinach in the G-DNA system could absorb more nitrogen from the nutrient solution and yield more with the same amount of absorbed nitrogen compared to DWC and C-Tree systems. These findings indicate that the G-DNA system holds greater potential for improved NUE, and higher spinach yield compared to the C-Tree system. However, the G-DNA and C-Tree systems had no significant effect on WUE.