IoT-based Soil Salinity Monitoring using sensors in Watermelon cultivation (Smart Agriculture Research, 2024).

In early 2026, the use of Internet of Things (IoT) for monitoring soil salinity has become a cornerstone of precision watermelon cultivation, particularly in regions like the Pothwar plateau or the semi-arid belts of South Asia and the Mediterranean.

Research published in Smart Agriculture Research (2024) and subsequent 2025 updates focuses on moving beyond simple data collection to Predictive Salinity Modeling.

🛰️ 1. The IoT Architecture for Salinity Monitoring

Watermelon is a “moderately salt-sensitive” crop, with yields dropping by 25% once soil electrical conductivity (EC) exceeds 3.5 dS/m. The 2024-2026 IoT frameworks utilize a layered approach to manage this risk:

• Sensor Layer:
  • Electrical Conductivity (EC) Sensors: Integrated 3-in-1 probes (EC + Moisture + Temperature) are buried at two depths: 15 cm (root zone) and 40 cm (leaching zone).
  • Resistivity Probes: New research (2024) uses soil resistivity as a proxy for salinity. Sensors measure the resistance between two electrodes; as salt concentration increases, resistance decreases.
• Transmission Layer: Data is sent via LoRaWAN (Long Range Wide Area Network) or NB-IoT, which are preferred for watermelon fields due to their low power consumption and ability to transmit through dense foliage over several kilometers.
• Application Layer: Farmers receive real-time alerts via mobile apps (like Blynk or custom platforms) when salinity hits the “Warning Threshold” of 2.2 dS/m.

🤖 2. The ANN-Resistivity Model (2024 Breakthrough)

A significant development in 2024 is the use of Artificial Neural Networks (ANN) to translate raw sensor data into actionable salinity maps.

• The Logic: Soil salinity is not just about salt; it’s affected by moisture and temperature. The ANN model takes inputs from soil resistivity, moisture, and temperature sensors to filter out “noise.”