1. Introduction
Conventional irrigation scheduling in water-stressed regions often ignores real-time soil conditions, leading to either water wastage or crop stress. Low-power wide-area network technologies such as LoRaWAN make continuous field-scale sensing economically viable for smallholder farms.
2. Methodology
Twelve sensor nodes measuring soil moisture, temperature and electrical conductivity at 15cm, 30cm and 45cm depths were deployed across a 4-hectare groundnut field and connected via a LoRaWAN gateway to a cloud dashboard. An edge controller applied threshold-based rules derived from crop water stress coefficients to actuate solenoid valves, with performance compared against an adjacent plot under conventional calendar-based irrigation.
3. Results
The LoRaWAN plot consumed 34 percent less irrigation water over the season while yield differed by less than 3 percent from the control plot, a statistically insignificant difference (p=0.41). Median packet delivery ratio across the 900m field span was 96.2 percent, and sensor nodes averaged 8.3 months of operation on a single 3.7V 6000mAh battery.
4. Conclusion
The results confirm that LoRaWAN-based sensing can materially reduce irrigation water use without compromising yield, offering a scalable option for resource-constrained farms. Future work will incorporate satellite-derived evapotranspiration estimates to refine the rule engine.
References
[1] Vasisht D. et al., FarmBeats: An IoT platform for data-driven agriculture, NSDI, 2017. [2] Ferrandez-Pastor F. J. et al., Precision agriculture design using wireless sensor networks, Computers and Electronics in Agriculture, 2016. [3] Foukalas F. et al., Coverage and capacity analysis of LoRaWAN, IEEE IoT Journal, 2019. [4] Kamienski C. et al., Smart water management platform, Sensors, 2019.