Optimizing Water Volume for Carrots (Daucus carota) Grown in a Deep-Water Culture System

Efficient water management is essential for sustainable agriculture, particularly for crops like carrots that are traditionally grown in soil systems with high water consumption, averaging 4500-6000 m³/ha. Hydroponics offers a potential alternative due to its higher water-use efficiency, yet root crops have been understudied because of system design and economic challenges. This study evaluated the effects of different hydroponic solution volumes on the growth of carrots (Daucus carota cv. Mokum) in a Deep-Water Culture (DWC) system to address knowledge gaps regarding their feasibility in soilless production. Experiments were conducted in a controlled greenhouse using three solution volume treatments (50% with 10.75 L, 75% with 16.13 L, and 100% with 21.50 L) applied to 12 plants per treatment across two repeated experiments. Biomass production, water use efficiency, and total carotenoid concentration were assessed after eight weeks. The 100% (21.50 L) volume treatment produced the greatest shoot and root biomass, whereas the 50% (10.75 L) volume treatment significantly increased total carotenoid concentration, particularly in the second trial. Despite lower water inputs, water use efficiency did not differ statistically among treatments. These results indicate that carrots can be successfully cultivated in DWC systems, though further optimization, such as using narrower containers, may be required to improve efficiency and competitiveness with soil-based production.