LoRaWAN based internet of things (IoT) system for precision irrigation in plasticulture fresh-market tomato

Precision irrigation with sensors has proven to be effective for water saving in crop production. An Internet of Things (IoT) system is necessary for monitoring real-time data from sensors and automating irrigation systems. Long-range wide-area network (LoRaWAN), a type of low-power wide-area network (LPWAN), is a low-cost and easily implemented IoT system which can be used for precision crop irrigation. In this study, a LoRaWAN based IoT system was developed and evaluated as a precision irrigation tool on fresh-market tomato production in a plasticulture system. Four irrigation scheduling treatments were designed and tested, including irrigation based on crop evapotranspiration (ET), soil matric potential sensors (Watermark 200SS-5) at -60 kPa (MP60) or -40 kPa (MP40), and GesCoN fertigation decision support system (DSS). The treatments were arranged based on a randomized complete block design with four replicates. System feasibility, irrigation water use efficiency (iWUE), and crop yield were evaluated. Throughout the season, the overall water use efficiencies were 22.2, 26.5, 27.9, and 28.4 kg·m−3 for ET, MP60, MP40, and GesCoN, respectively. The results indicated that treatment MP60 and GesCoN had 15.2 and 22.1% higher marketable fruit yield than ET, while, MP40 had 12.5% lower marketable yield compared to ET. Overall, the LoRaWAN-based IoT system performed well in terms of power consumption, communication, sensor reading, and valve control. These results suggested that the IoT system can be implemented for precision and automatic irrigation operations for vegetable and other horticultural crops with enhancing crop's water use efficiency and sustainability.