A five-stage protocol for systematic measuring and monitoring soil carbon and greenhouse gas fluxes in complex estates

Background and Aims Plant-soil interactions are critical in governing soil carbon (C) stocks and greenhouse gas (GHG) fluxes, but they vary significantly across land uses, soil types, and soil management practices. Finding potential intervention that could enhance soil C and GHG fluxes relies on reliable baseline data that capture these variations. Complex estates, characterised by such heterogeneous conditions, require standardised protocols to ensure reproducibility and comparability across sites. Methods This study introduces a five-stage protocol for systematically measuring and monitoring soil C stocks (including organic and inorganic forms) and GHG fluxes. The protocol is designed for "Time-Zero" (T = 0) baseline assessments and the strategic selection of monitoring sites for long-term soil sampling and GHG flux measurements. The approach was tested at RAF Leeming (Yorkshire, UK), a estate with varied land uses, soil types, and management practices. Results The protocol provides a rigorous, reproducible and adaptable framework for obtaining robust baseline data. It facilitates the quantification of soil C and GHG fluxes, while it can guide site-specific interventions, ensuring that aspects such as plant and soil interactions are considered for comparability purposes. Its design is scalable, with applications extending to urban areas, military installations, airports, and other managed estates. Conclusions The proposed protocol enables standardised, transparent soil C and GHG monitoring to meet internationally accepted standards. We advocate for its broad implementation across estates with varying land uses and soil characteristics to support sustainable soil management and climate mitigation efforts.