Towards Low-Cost Low-Power Activity-Aware Soil Moisture Sensing Platform for Large-scale Farming

2026-04-29

AI Summary

This study addresses the high deployment and maintenance costs that hinder the large-scale adoption of soil moisture monitoring systems in agricultural fields. The authors propose a battery-free, end-to-end mobile sensing platform comprising buried, self-powered sensor nodes and an agricultural vehicle-mounted mobile base station that automatically collects and relays soil moisture, temperature, and environmental data along routine farming routes. The system innovatively integrates a self-powered electrochemical probe, solar energy harvesting, a high-impedance analog front-end, and a finite state machine–based low-power communication protocol. Achieving long-term stable operation at ultra-low cost (under $35 per node), it sustains 21 days of continuous operation per charge, supports 1-km communication range at 2 dBm transmit power, enables 70 days of indoor continuous sensing, and ensures complete data recovery under intermittent connectivity—seamlessly integrating into existing agricultural workflows.

Abstract

Deep understanding of a field's soil moisture content is the leading indicator for predicting crop yields and making data driven decisions for irrigation and application of topical chemicals for drought resilience. Despite this importance, the cost of adopting and maintaining IoT infrastructure prevents modern farms from employing widespread real time soil moisture sensors. We present an end-to-end platform of buried battery-free sensor nodes and a mobile basestation that leverages the farmer's daily routine for data retrieval. Each node features a self-powered galvanic soil-moisture probe, employing a high impedance analog front end to enable durability. Operating entirely on harvested solar energy for up to 21 days on a single capacitor charge, each node collects soil moisture, temperature, and environment condition data. Using a predictable finite-state machine, handshake-based data exchanges occur with a basestation affixed to standard farming vehicles designed to listen for the nodes while moving through the farm. Our platform organizes all sensor, link-quality, and location data into an easy-to-interpret dashboard to seamlessly integrate with the farmer's everyday routine. Costing less than $35, the platform is a financially accessible, accurate, and easily scalable platform that enables persistent, regular data collection from the most rural plots without adding to or impeding farming operations. Experimental evaluation demonstrates reliable communication over 1 km at 2 dBm transmit power, stable sensor readings over 70 days of indoor operation, and continuous data recovery during multiple periods of intermittent connection.

Problem

• soil moisture sensing
• low-cost IoT
• large-scale farming
• battery-free sensors
• agricultural monitoring

Innovation

• battery-free sensing
• soil moisture monitoring
• energy harvesting
• mobile base station
• low-cost IoT