Continuous Monitoring of Soil Carbon Dioxide Emissions Using an Arduino Platform

This study introduces an innovative approach using an Arduino microcontroller equipped with onboard programmable sensors for continuous, real-time in-field monitoring of soil carbon dioxide (CO2) emissions. By minimising soil disturbance and allowing in-situ monitoring, this method aims to provide more precise and reliable data, thereby enhancing our understanding of soil carbon processes and soil health. To test the application of the Arduino sensor platform, fresh soil samples from six fields at Hartpury University Farm were included in the study. Two arable (Big Catsbury and Little Catsbury), two temporary grass (North and South Dandies) and two permanent grass (Broadfield and Duckfield) fields were studied. The results highlighted significant variability in CO2 concentrations, with high peak concentrations indicating short-term spikes in emissions. For example, a peak of 1362 ppm for permanent grass and data suggested substantial short-term emissions dynamics. The mean CO2 concentration was 1031 ppm for permanent fields, with moderate relative variability (11% coefficient of variation). Arable and temporary grass fields also showed higher peak concentrations and greater differences between peak and average concentrations, implying more susceptibility to intermittent activities or conditions. In contrast, permanent pastures exhibited both high average CO2 levels and high peak CO2 levels, indicating more consistent emissions over time. Field-specific observations suggest significant and continuous sources of emissions and our technology shows potential for assessing the variability with and between fields that is crucial for optimising field management, maintaining soil health, and developing strategies to mitigate CO2 emissions. The proposed monitoring approach can be used to detect long-term trends, seasonal variation, and short-term pulses in soil CO2 emissions at a field and farm scale. This innovative technique has the potential to bridge existing knowledge gaps, support the broader research community, and contribute to sustainable soil management practices essential for the future of our society and planet.