Evaluation of alternative soilless growing systems for resource use efficiency, yield and quality performance of multi-leaf lettuce

Soilless growing systems (SGS) are increasingly used for both small-scale and large-scale industry vegetable production.
Although these systems offer several benefits, such as increased water and nutrient use efficiency, exclusion of soilborne issues, and improved quality control, their sustainability is often questioned due to differences in efficiency and energy requirement.
Only a few studies have examined side-by-side the performance of alternative SGS in terms of crop yield, quality, and resource use efficiency.
To address this knowledge gap, a study was conducted to compare five distinct alternative SGS for their impact on yield, water efficiency, and nutritional quality of both green and red Salanova^A(r) lettuce varieties.
The SGS compared were namely drip irrigation, deep water culture (DWC), ebb and flow, nutrient film technique (NFT), and Kratky.
Across SGS, green Salanova^A(r) lettuce had higher fresh weight (11.7%) and nitrate content (18%) compared to red Salanova^A(r) lettuce, whereas red lettuce had about 100% higher levels of total phenols, antioxidant activity, and flavonoids, compared to green lettuce.
Among the SGS, the NFT system provided higher leaf area, fresh and dry weight, but had higher nitrate levels and lower antioxidant activity.
When considering water consumption, the Kratky system consumed less water per plant, nearly 35.1% less than the ebb and flow system, which required a higher amount of nutrient solution per plant.
Drip irrigation and ebb and flow systems exhibited lower water use efficiency compared to Kratky, DWC, and NFT. Thus, the choice of alternative SGS, although in part influenced by the lettuce genotype, should be guided by specific objectives and targets in terms of yield, water use efficiency, nitrate content, and nutritional values.

International Symposium on New Technologies for Sustainable Greenhouse Systems: GreenSys2023

P. Poudel, F. Di Gioia

hydroponic systems, water use efficiency, ebb-and-flow, deep water culture, drip irrigation, Kratky, nutrient film technique

https://doi.org/10.17660/ActaHortic.2025.1426.45