Abstract Subsurface soil organic carbon ( SOC ) is a large but still poorly understood component of the global carbon cycle.

The gap

Consensus across the literature

Supporting evidence — 3 representative gaps

• Electrical conductivity measurements as proxies for diffusion-limited microbial activity in soils under controlled laboratory conditions (2026) · doi

  and mechanisms, Arch. Agron. Soil Sci., 65, 1446–1459, https://doi.org/10.1080/03650340.2019.1566713, 2019. in desert soils: Species, Autret, B., Mary, B., Chenu, C., Balabane, M., Girardin, C., Bertrand, M., Grandeau, G., and Beaudoin, N.: Alternative arable cropping systems: A key to increase soil organic carbon storage? Results from a 16 year field experiment, Agr. Ecosyst. Environ., 232, 150–164, https://doi.org/10.1016/j.agee.2016.07.008, 2016. Autret, B., Guillier, H., Pouteau, V., Mary, B., and Chenu, specific mineralization rates of organic car- C.: Similar bon and nitrogen in incubated soils under contrasted arable cropping systems, Soil Till. Res., 204, 104712, https://doi.org/10.1016/j.still.2020.104712, 2020. Bellone, D., Jeuffroy, M.-H., Bertrand, M., Mistou, M.-N., Barbu, C., Ballini, E., Morison-Valantin, M., Gauffreteau, A., and Pashalidou, F. G.: Are innovative cropping systems less depen- dent on synthetic pesticides to treat Septoria leaf blotch (Zy- moseptoria tritici) than conventional systems?, Crop Prot., 170, 106266, https://doi.org/10.1016/j.cropro.2023.106266, 2023. Blanchy, G., Deroo, W., De Swaef, T., Lootens, P., Quataert, P., Roldán-Ruíz, I., Versteeg, R., and Garré, S.: Closing the phe- notyping gap with non-invasive belowground field phenotyping, SOIL, 11, 67–84, https://doi.org/10.5194/soil-11-67-2025, 2025. Castellini, M. and Ventrella, D.: Impact of conventional and min- imum tillage on soil hydraulic conductivity in typical crop- ping system in Southern Italy, Soil Till. Res., 124, 47–56, https://doi.org/10.1016/j.still.2012.04.008, 2012. Çelik, ˙I., Günal, H., Acir, N., Barut, Z. B., and Budak, to compare tillage systems M.: Soil quality assessment SOIL, 12, 703–714, 2026 https://doi.org/10.5194/soil-12-703-2026 O. Fülöp et al.: Electrical conductivity as proxy for soil microbial activity 713 in Cukurova Plain, Turkey, Soil Till. Res., 208, 104892, https://doi.org/10.1016/j.still.2020.104892, 2021. Chabert, A. and Sarthou, J.-P.: Conservation agriculture as a promising trade-off between conventional and organic agricul- ture in bundling ecosystem services, Agr. Ecosyst. Environ., 292, 106815, https://doi.org/10.1016/j.agee.2019.106815, 2020. Colas, E.: Impact de l’humidité et des solutions salines sur du Buntsand- françaises, le comportement stein , Le moteur de https://doi.org/10.70675/96ade2f0z6a11z48faza984z3ae9b0ef3c0f, 2011. recherche des dimensionnel thèses grès de Cosentino, D., Chenu, C., and Le Bissonnais, Y.: Aggregate sta- bility and microbial community dynamics under drying–wetting cycles in a silt loam soil, Soil Biol. Biochem., 38, 2053–2062, https://doi.org/10.1016/j.soilbio.2005.12.022, 2006. Crawford, R. L.: Microbial Diversity and Its Relationship to Planetary Protection, Appl. Environ. Microb., 71, 4163–4168, https://doi.org/10.1128/AEM.71.8.4163-4168.2005, 2005. Crowther, T. W., Van Den Hoogen, J., Wan, J., Mayes, M. A., Keiser, A. D., Mo, L., Averill, C., and Maynard, D

  Keywords: soil https systems chenu cropping organic environ till still conventional microbial soils autret mary bertrand
• Mineral-mediated stability of organic carbon in soil and relevant interaction mechanisms (2024) · doi

  5.1. Structure–property–activity relationship for the interactions between organic carbon and minerals Based on the proposed reaction mechanisms, the interaction route between the organic carbon and minerals is highly variable and mainly depends on the structure and characteristics of both minerals and organic carbon. Different interaction routes can lead to contrasting fate of soil carbon. Current studies mainly evaluate this impact by selecting specific natural organic carbon or minerals without a well-designed control on the properties, speciation, and composition. The currently available re- sults are essential for explaining the interaction mechanisms under spe- cific conditions in the soil environment, but they might be less instrumental in evaluating and predicting the potential interactions and long-term stability in a broad spectrum of soils. The impact of SOC composition, abundance of surface functionality, aromaticity, molecular weight distribution, and so on, on the interactions with soil minerals merits a more profound understanding based on the molecular and nano- sized scale design. Furthermore, the speciation, particle size, crystal- linity, and surface properties of the soil minerals will concurrently and significantly affect the interactions with SOC, which needs further exploration in mechanistic studies. 5.2. Variation of organic carbon-mineral interactions and carbon stability with time Many studies evaluated the interaction mechanisms between organic carbon and minerals in the soil environment, but most have only focused on one single snapshot rather than the entire timeline of the interaction process. These studies often span several months or years under relatively stable conditions, which may not always be guaranteed in the natural environment. The interactions between fresh organic carbon and min- erals at the initial stage will change their properties, leading to a different interaction route in later stages. Different alternations of the properties and compositions of SOC and minerals might occur in the second stage, causing distinctive interaction processes afterward. In other words, the primary interactions are variable with dynamic equilibrium, which is related to the changes in the environmental situations (e.g., variation of temperature or precipitation). The full-view findings across different stages can help to explain the past (formation route), the present (current content and existing forms), and the future (predicted transformation and long-term stability) of organic carbon and minerals. 5.3. Spatiotemporal variability of the interactions between organic carbon and minerals Many studies have investigated the interactions between organic carbon and minerals under specified conditions based on the studied soil, while its variation is widely overlooked. In addition to the compositions and properties of the organic carbon and minerals, other variability related to the site locations and weather conditions, e.g., soil pH, tem- perature, water content, co-existing moieties, and redox conditions, can 68 Z. Xu, D.C.W. Tsang Eco-Environment & Health 3 (2024) 59–76 also significantly affect the interaction processes. Linking the cross- linking properties of soils with the potential interactions between organic carbon and minerals can be a fundamental direction for more accurately evaluating soil carbon storage.

  Keywords: carbon minerals organic interactions interaction soil properties conditions different environment based mechanisms route stability variation
• The depth distribution of organic carbon in the soils of eastern Australia (2016) · doi

  Abstract Subsurface soil organic carbon ( SOC ) is a large but still poorly understood component of the global carbon cycle.

  Keywords: carbon abstract subsurface soil organic large still poorly understood component global cycle