Smart fertigation system for tomato greenhouses using plant stem impedance sensing
IoT-based fertigation platform that combines soil parameter monitoring with novel plant stem electrical impedance measurements to detect water stress, nutrient shortages, and parasitic infections in real time. Enables precision irrigation and fertilization, reducing chemical and water use in greenhouse tomato cultivation.
Overview
This solution introduces a smart fertigation system designed specifically for tomato greenhouses. Unlike conventional environmental monitoring, the system directly measures the electrical impedance of the plant stem to assess plant health with greater precision. By correlating stem impedance variations with the plant's daily cycle and stress conditions, the technology can detect water stress, nutrient shortages, and parasitic infections earlier than traditional soil- or climate-based methods. The approach is analogous to personalized medicine applied to agriculture, providing plant-specific insights that enable targeted irrigation and fertilization decisions.
Technical specifications
Key features:
- Direct plant status monitoring through stem electrical impedance measurement
- Integration with commercial soil parameter sensors for comprehensive environmental data
- Custom IoT-compatible sensor hardware that is small, low-power, and wireless for easy greenhouse deployment
- Centralized data processing on a server for algorithm-driven fertigation control
- Smart fertigation algorithm designed to optimize water and chemical usage
- Validated correlation between stem impedance data and soil water content as a water stress indicator
- Detection capability for abnormal plant behavior, including pre-death signals observed across multiple test subjects
Technology readiness level
The core concept has been validated through bench instrument testing and novel IoT-compatible systems on tobacco plants, demonstrating high correlation between stem impedance and soil water content. The next phase involves developing a fully integrated sensor system combining commercial soil sensors with stem impedance measurements, followed by field deployment in tomato greenhouses to build and refine the fertigation algorithm. The system is currently at a prototype-to-pilot stage, with planned greenhouse validation and data-driven model development underway.
About Politecnico di Torino
Politecnico di Torino is a major public, STEM-focused polytechnic university in Italy known for applied research and deep industry partnership. Companies engage on campus through co-located labs, shared facilities, and corporate-access research space, with options from sponsored projects to multi-year agreements. Being in Turin embeds the university in a dense mobility and manufacturing ecosystem, enabling rapid prototyping, pilot testing, and links to OEM supply chains. Research is supported by competitive European Commission programs alongside national and regional funding, often in collaboration with industry. A dedicated technology transfer office and an on-campus startup incubator streamline IP, licensing, and spinout creation.
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