Comparative analysis of closed hydroponic systems and planting seasons for lettuces

Abstract

Hydroponic cultivation techniques offer innovative solutions to address challenges in conventional agriculture, such as soil infertility, disease outbreaks, and poor drainage. This study focuses on comparing the performance of different closed hydroponic systems for lettuce cultivation across distinct winter and summer planting seasons. Four closed hydroponic systems—deep water culture (DWC), nutrient film technique (NFT), media-bed system (MB), and sandponic (SP)—were evaluated for their impact on vegetative growth parameters, leaf nutrient content, chlorophyll and carotene levels, and water consumption. Our findings reveal that the DWC and NFT systems exhibited greater yield increases in winter (81.90% and 75.64%, respectively) and in summer (29.25% and 18.19%, respectively) compared to other systems. Notably, DWC lettuces consistently showed higher chlorophyll A, B, and carotene content, highlighting their potential for enhanced photosynthetic efficiency and nutritional value. The findings suggest that DWC is well-suited for achieving robust and vigorous lettuce growth and almost invariable water consumption in different seasons. NFT system also showed promising results, particularly effective water use per plant in both seasons. However, the water evaporation rate for this closed system was higher in summer. Moreover, our findings suggest that utilizing growth media in hydroponic systems can facilitate the retention of oxygen and nutrients. These findings can contribute to improving the selection of hydroponic systems and adapting them to seasonal variations in controlled greenhouse environments. They offer valuable insights and practical knowledge for precisely cultivating lettuce, promoting sustainable and efficient year-round production of leafy vegetables.