Optimizing Sensor-Based Irrigation Management in a Soilless Vertical Farm for Growing Microgreens

Abstract

With water resources constantly becoming scarcer, and 70% of freshwater used for the agriculture sector, there is a growing need for innovative methods to increase water use efficiency (WUE) of food production systems and provide nutrient-dense food to an increasing population. Sensor technology has recently been introduced to the horticulture industry to increase resource use efficiency and minimize the environmental impacts of excessive water use. Identifying the effects of irrigation levels on crop performance is crucial for the success of sensor-based water management. This research aimed to optimize WUE in a soilless microgreen production system through identification of an optimal irrigation level using a sensor that could facilitate the development of a more efficient, low-cost automated irrigation system. A dielectric moisture sensor was implemented to monitor water levels at five irrigation setpoints: 7.5, 17.5, 25, 30, and 35 percent of the effective volume of the container (EVC) during a 14-day growth cycle. To validate the sensor performance, the same irrigation levels were applied to a parallel trial, without sensor, and water levels were monitored gravimetrically. Plant water status and stress reaction were evaluated using infrared thermal imaging, and the accumulation of osmolytes (proline) was determined. Results showed that, proline concentration, canopy temperature (Tc), canopy temperature depression (CTD), and crop water stress index (CWSI) increased at 7.5% EVC in both sensor-based and gravimetric treatments, and infrared index (Ig) and fresh yield decreased. The dielectric moisture sensor was effective in increasing WUE. The irrigation level of 17.5% EVC was found to be optimal. It resulted in a WUE of 88 g/L, an improvement of 30% over the gravimetric method at the same irrigation level. Furthermore, fresh yield increased by 11.5%. The outcome of this study could contribute to the automation of precision irrigation in hydroponically grown microgreens.

Using bibliometric analysis to map innovative business models for vertical farm entrepreneurs

“…, 2015). The refinement of hydroponic cultivation can be a vital tool for vertical farming (Tavan et al. , 2021).…”

“…Specifically, the study emphasises the easy integration of the vertical farm in the context of smart cities (Salmon, 2020). The substantial technological impact (Tavan et al. , 2021) encourages developing a new agri-food market within the urban context (Bresciani et al.…”

“…The term hydroponics considers off-ground cultivation. According to Tavan et al (2021), there is a growing need for innovative methods to increase the water use efficiency of food production systems and provide dense food for an increasing population. To this end, the refinement of hydroponic cultivation can be a vital tool for vertical farm crops.…”

“…Technological elements can help achieve these goals, and urban agriculture represents an environmentally friendly and efficient option within cities (Sany e- Mengual et al, 2015). The refinement of hydroponic cultivation can be a vital tool for vertical farming (Tavan et al, 2021). Therefore, entrepreneurship in this field must aim for an efficient growing system aided with technologies in achieving environmental and economical sustainability goals, creating profit in an urban system that needs more and more nutrition (Al-Kodmany, 2018).…”

“…Specifically, the study emphasises the easy integration of the vertical farm in the context of smart cities (Salmon, 2020). The substantial technological impact (Tavan et al, 2021) encourages developing a new agri-food market within the urban context (Bresciani et al, 2018). Therefore, smart cities qualify as one of the most favourable contexts for an agri-food entrepreneur (Gabriele et al, 2017).…”