Comparative Analysis of Deep Flow and Nutrient Film Technique in Vertical Farming

Unlike traditional agriculture, vertical farming systems utilize soilless cultivation methods. Various solid media cultures or hydroponic methods can be employed for soilless farming. The selection of methods and materials should be based on criteria such as economic feasibility, accessibility, sustainability, ease of use and management, as well as operating costs, efficiency, and quality. In these intensive production systems, it is crucial to design, establish, and operate them like a factory to maintain high profitability. Since plant growth and development in vertical farming are faster compared to other agricultural methods, all harvesting, planting, irrigation, and system maintenance operations need to be carried out promptly. Therefore, determining which method or methods are more efficient in these systems is highly important. For the widespread adoption and sustainability of vertical farming, analyses of different methods and systems are necessary. The aim of this study is to contribute to the literature on methods for vertical farming facilities. In this study, lettuce, rocket, cress, and dill were cultivated under controlled climatic conditions in a fully enclosed and computer-controlled laboratory using the Deep Flow Technique (DFT) and Nutrient Film Technique (NFT). The growth performance, yield characteristics, and quality parameters of the plants grown were compared between the two systems. For this comparison, total fresh weight, plant height and width, stem diameter, leaf count, discarded leaf count, and branching (in applicable species) were used. Additionally, the energy efficiency of the vertical farming systems established using the two techniques was evaluated. The energy use efficiency (EUE) of the NFT and DFT systems was calculated as 4.16 g kWh⁻¹ and 5.89 g kWh⁻¹, respectively. The DFT system increased the total fresh weight and stem diameter in lettuce and dill plants by an average of 5%. Due to the higher biomass production in the DFT system, its EUE was calculated to be 5% higher.