Within the European PEATLESS project, CESENS is developing a digital sensorisation system designed to monitor new low peat content substrate alternatives. These solutions are intended for use in mushroom cultivation as well as in ornamental plant production and horticultural nurseries.

Last week, taking advantage of the start of a new mushroom growing cycle at the facilities of CTICH—the project coordinator—a preliminary sensor installation was carried out under real production conditions. This setup was conceived as a testbed to help define the technical specifications of the final system.

Measurement technologies under evaluation

In this first trial, several technologies for measuring moisture, temperature and electrical conductivity were tested, with the aim of comparing their performance in a particularly challenging environment. The growing beds include an approximately 5 cm surface casing layer used during the final fruiting stage to support mushroom development.

Specifically, the trial is assessing:

• Capacitive sensors, widely used due to their low power consumption and ease of integration.

• Electromagnetic sensors with a larger measurement volume, capable of averaging conditions across a greater volume of substrate.

• Frequency Domain Reflectometry (FDR) sensors, enabling a more detailed characterisation of water content and electrical conductivity.

In addition, two installation configurations were implemented—vertical insertion from the surface and side placement buried within the substrate—to analyse how installation geometry affects the stability and representativeness of the readings.

The data collected throughout the month-long trial will support the selection of the most suitable technologies, the definition of installation criteria, and the initial adjustment of substrate-specific calibration equations for the new low peat growing media to be developed within the project.

Key challenge: coverage and connectivity

Beyond evaluating the sensors themselves, these early trials led by CESENS are proving essential for identifying the main technical challenges that will shape the system’s final design—most notably, data transmission.

Many mushroom production units are similar to cold-store chambers built with sandwich panels, which creates a strong electromagnetic shielding effect comparable to a Faraday cage. This significantly reduces the coverage of conventional communications (GSM), making it difficult to transmit data from inside the growing rooms to external servers.

This constraint is leading the PEATLESS project to assess communication alternatives with greater penetration capability, such as LoRaWAN networks supported by intermediate repeaters, with the aim of ensuring robust, continuous and energy-efficient connectivity in these closed environments.

Other factors—such as high ambient humidity and the lack of natural light—are also being considered as key design variables to ensure the long-term reliability of the equipment.

Next steps

As the trial progresses and a longer time series of data becomes available, the technical decisions will be progressively consolidated, enabling CESENS to define a sensorisation solution tailored to these new substrates and aligned with the PEATLESS project’s sustainability and digitalisation objectives.