Monitoring soil organic carbon (SOC) stocks is critical for understanding changes in soil health, supporting land management, and informing climate change mitigation policies. This study presents a pragmatic and scientifically robust approach for national-scale resampling of SOC monitoring sites in Australia. Using legacy data from the Soil Carbon Research Program (SCaRP), which surveyed over 4000 agricultural sites between 2009 and 2012, we developed a hybrid resampling framework that combines model-based and design-based sampling principles. A subset of 308 sites comprising 207 ‘standard’ (composited) and 101 ‘detailed’ (replicated) sites (sampling support is 25 m × 25 m) was selected using a two-stage procedure involving k-means clustering, fuzzy allocation, and conditioned latin hypercube sampling. Covariates representing SOC drivers, including climatic, biophysical, and management-related factors, were processed using discounted temporal weights to capture antecedent conditions. The final set of 308 resampled sites (7.57% of SCaRP) reflects the diversity of Australian agroecological conditions and maintains statistical representativeness across key SOC drivers. This was demonstrated through Jensen–Shannon divergence analysis, which yielded values close to zero, indicating high efficiency in the resampling campaign. The resampling approach outlined here demonstrates how legacy soil datasets can be efficiently leveraged through resampling designs to meet practical constraints while preserving scientific rigour. These findings have broad implications for long-term SOC monitoring, particularly in contexts where site access, budget, and temporal sensitivity pose challenges.
S. Karunaratne, Liz Stower, S. Ugbaje et al.· Soil Research· 1 citation
The Soil Organic Carbon Monitoring project provides a dataset from 308 agricultural sites distributed across Australia's major farming regions, integrating soil attributes (biological, chemical and physical) and elemental properties with detailed temporal land-management information. Baseline soil samples were collected between 2009 and 2012 under the Soil Carbon Research Program, and the same sites were resampled between 2022 and 2025. The dataset includes laboratory measurements of soil organic carbon, total nitrogen, pH of 1:5 soil/water suspension, pH of 1:5 soil/0.01 M calcium chloride extract, electrical conductivity (EC) of 1:5 soil/water extract, whole-soil bulk density, permanganate-oxidisable carbon, and soil elemental composition measured by portable X-ray fluorescence for a wide suite of major and trace elements. Ten soil samples were collected at three depths (0 - 0.10, 0.10 - 0.20, and 0.20 - 0.30 m) on a 25 × 25 m grid, except for the rangeland sites, where a large polygon area was used as the sampling support. At some sites, cores were kept separate (not composited based on the depth supports, known as detailed sites), while at other sites, they were composited at each depth support. Particle size distribution and direct measurements of soil organic carbon fractions (particulate, humic and resistant carbon) were performed on a spatially representative subset of 300 samples, selected to capture variability in soil properties inferred through the gathered infrared spectral datasets for the whole dataset. In addition, paddock-level land-management histories spanning 2010-2023 document crop and pasture types, tillage and residue management, fertiliser application, irrigation status, and grazing. These records enable estimation of annual carbon inputs using a multi-model crop simulation ensemble. All components are spatially referenced and interoperable, allowing integration of soil properties, agriculture management practices, and positional data. This resource supports benchmarking of SOC stocks and changes, evaluation of management impacts, and development of monitoring, reporting, and verification frameworks for soil carbon and soil health in Australian agroecosystems.
C. Pasut, C. Asanopoulos, Xueyu Zhao et al.· Scientific Data· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
