A low-cost multi-channel automated chamber system for real-time monitoring of CO2 and H2O fluxes in maize fields

• Developed a low-cost multi-channel automated chamber system (Loco-MACS). • Loco-MACS enables real-time summer maize cropland CO 2 and H 2 O flux monitoring. • The system achieved high accuracy for CO 2 and H 2 O measurements at low cost. • Integrated in-chamber water vapor monitoring component minimizes H 2 O flux errors. • Loco-MACS can be potentially used compared to expensive commercial systems. Precise carbon dioxide (CO 2 ) and water vapor (H 2 O) flux measurements are critical for understanding how ecosystems work, thereby improving agricultural water use efficiency. Conventional chamber-based systems are widely used to monitor CO 2 and H 2 O fluxes. However, their widespread adoption in precision agriculture has been significantly hindered by high costs and uncertainty in CO 2 and H 2 O measurements. The development of a solar-powered low-cost multi-channel automated chamber system (Loco-MACS) is being analysed in this paper for real-time, high-precision, and synchronous monitoring of CO 2 and H 2 O fluxes in maize fields. Loco-MACS integrates a cost-effective NDIR CO 2 sensor and employs multiplexing technology to sequentially control ten automated chambers. System performance was evaluated through comparative testing against a commercial LI-8100A system and a micro-lysimeter. Statistically, CO 2 fluxes measured by Loco-MACS exhibited strong agreement with the commercial system ( R 2 = 0.93, RMSE = 0.32 μmol m -2 s -1 ), while H 2 O fluxes closely matched micro-lysimeter measurements ( R 2 = 0.85, RMSE = 0.05 mm h -1 ) with a minimal bias of 0.03 mm h -1 . Particularly, the H 2 O monitoring component maintained high precision even under high-humidity conditions by mitigating condensation errors. Long-term installation in maize field further demonstrated the system’s capability to continuously capture canopy-soil CO 2 and H 2 O flux dynamics, including diurnal and seasonal variations in Net Ecosystem Exchange ( NEE ), Soil Respiration ( RS ), Evapotranspiration ( ET ), and Evaporation ( E ). By combining long-term high accuracy, affordability, and scalability, Loco-MACS offers a cost-effective solution (€2153) for monitoring of CO 2 and H 2 O fluxes, supporting precision agriculture and ecosystem sustainability.