Sensor-Based Irrigation Reduces Water Consumption without Compromising Yield and Postharvest Quality of Soilless Green Bean

Abstract

Real-time monitoring of substrate parameters in the root-zone through dielectric sensors is considered a promising and feasible approach for precision irrigation and fertilization management of greenhouse soilless vegetable crops. This research investigates the effects of timer-based (TIMER) compared with dielectric sensor-based irrigation management with different irrigation set-points [SENSOR_0.35, SENSOR_0.30 and SENSOR_0.25, corresponding to substrate volumetric water contents (VWC) of 0.35, 0.30 and 0.25 m3 m−3, respectively] on water use, crop performance, plant growth and physiology, product quality and post-harvest parameters of soilless green bean (Phaseolus vulgaris L., cv Maestrale). In SENSOR treatments, an automatic system managed irrigation in order to maintain substrate moisture constantly close to the specific irrigation set-point. The highest water amount was used in TIMER treatment, with a water saving of roughly 36%, 41% and 47% in SENSOR_0.35, SENSOR_0.30 and SENSOR_0.25, respectively. In TIMER, the leaching rate was ≈31% of the total water consumption, while little leaching (<10%) was observed in SENSOR treatments. TIMER and SENSOR_0.35 resulted in similar plant growth and yield, while irrigation set-points corresponding to lower VWC values (SENSOR_0.30 and SENSOR_0.25) resulted in inadequate water availability conditions and impaired the crop performance. The study confirms that rational sensor-based irrigation allows to save water without compromising anyhow the product quality. In SENSOR irrigation management, in fact, especially in the case of optimal water availability conditions, it was possible to obtain high quality pods, with fully satisfactory characteristics during storage at 7 °C for 15 days.

Reduced Fertilization to Improve Sustainable Use of Resources and Preserve Postharvest Quality of Fresh-Cut Wild Rocket (Diplotaxis tenuifolia L.) in Soil-Bound and Soilless Cultivation

“…At the end of storage, the highest value of total phenols was observed in ScS-LF leaves (85.30 ± 2.02 mg gallic acid/100 g fw). These results prove the existence of a positive correlation between total phenols and antioxidant activity, as already reported for many fruit and vegetables [ 30 , 59 ], confirming that phenols highly contribute to the antioxidant activity of the product. In the present study, a significant increase in phenolic compounds was induced by low concentrations of nutrients in accordance with [ 23 ], which reported similar results for rocket leaves cultivated in a soilless system.…”

Sensor-Based Fertigation Management Enhances Resource Utilization and Crop Performance in Soilless Strawberry Cultivation

“…Compared to timer-based irrigation, sensor-based irrigation may considerably reduce water consumption and increase WUE, providing water (and fertilizers) on-demand just when plants require it and reducing the drainage fraction to minimum values (<10%). In previous studies recently conducted, increases in WUE, ranging from 25 to 70%, were observed with sensor-based compared to timer-based irrigation management for several horticultural crops, including lettuce [20], basil [19], green bean and rocket [13,14]. In the case of strawberry, an experiment conducted in Korea to investigate the potential application of an irrigation schedule based on FDR sensors and VWC measurement showed that the total irrigation volume was 1.7-fold higher with the timer-based than with sensor-automated irrigation, with no differences in terms of plant growth, fruit yield and soluble solid content [21].…”

“…Significant water savings are generally observed with soil moisture-based methods compared to other scheduling methods [28]. With specific reference to greenhouse vegetables, several recent studies confirm lower irrigation consumption with sensor-based compared to timer-based irrigation management [13,14,23].…”

“…However, the sustainability of soilless cultivation is closely related to the management of the NS. Traditionally, irrigation scheduling is based on the grower's decision and on the use of a timer, resulting in a water/nutrient solution automatic supply according to a prefixed schedule [13,14]. This generally leads to excessive irrigation and, consequently, water and fertilizer losses [15].…”

Dual path mechanism of promoting classical furniture and customer responses: From the perspective of empathy

“…Practical empathy is the foundation of cultural empathy, and cultural empathy is the superstructure of practical empathy, and there is both a bottom-up and top-down logical relationship between the above two. Consumers buy classical furniture products to meet their consumption needs, which can be based on a lower level of material need arising from the product itself which is the lowest level of needs or a higher level of the spiritual need arising from the product culture ( Palumbo et al, 2021 ). Only when consumers’ practical material needs are satisfied can they seek to satisfy their cultural spiritual needs ( Lienert, 2015 ).…”