Conclusions

While vertical aquaponic systems may increase the number of plants that can be grown per unit of surface area compared with horizontal systems, it is important that they also result in increased yields. From a commercial point of view, the effects of gradients within some types of vertical system on crop value will depend on how the crop is going to be processed and marketed. For example, if lettuce is grown to be sold as individual heads, then the non-uniform productivity of growing towers, living walls and static A-frame systems would be a potential weakness compared with conventional horizontal aquaponic systems or vertical stacked bed systems. However, if the crop is destined for pre-cut salad bags, then crop uniformity may be irrelevant, and the increased yield per unit area could be a significant advantage. Besides affecting crop yield and quality, harvest efficiency in vertical and multi-tier horizontal systems may also be adversely affected since it will require working at different heights. The costs of the different types of vertical growing system also vary widely, depending on their complexity and the degree of automation. Therefore, crop utilization and marketability, and an investigation of the cost‐to‐benefits ratio of these growing systems, will be the ultimate criteria to decide whether vertical aquaponics can provide a viable alternative to conventional horizontal systems.

Copyright © Partners of the Aqu@teach Project. Aqu@teach is an Erasmus+ Strategic Partnership in Higher Education (2017-2020) led by the University of Greenwich, in collaboration with the Zurich University of Applied Sciences (Switzerland), the Technical University of Madrid (Spain), the University of Ljubljana and the Biotechnical Centre Naklo (Slovenia).