The Innovation Team of Saline-alkali Soils Amelioration at the Institute of Agricultural Resources and Regional Planning (IARRP), Chinese Academy of Agricultural Sciences (CAAS), has achieved significant advancements in the theoretical mechanisms of soil carbon sequestration. Researcher at the Institute of Agricultural Resources and Regional Planning have advanced soil carbon sequestration theories emphasizing the importance of redefining mineral-associated organic matter (MAOM) saturation. This breakthrough enhances the predictions of MAOM dynamics and sequestration potential, offering valuable insight for refining global carbon cycle models and carbon sequestration strategies. The perspective was published in the top-tier soil science journal "Soil Biology and Biochemistry" (IF 9.8).

Mineral-associated organic matter (MAOM) is an important carbon reservoir in relation to soil organic carbon sequestration over long timescales, and its saturation status is pertinent to the judicious formulation of agricultural management practices and global climate mitigation strategies. However, the existence of MAOM saturation is controversial due to the ambiguity of the MAOM concept and the variability of the underlying model. Based on this, we update and extend the concept of MAOM saturation into theoretical and apparent components, and propose the hypothesis that clay minerals, microbial communities, and input organic matter regulate the apparent saturation of MAOM. The theoretical saturation of MAOM represents the maximum sequestration potential of MAOM in natural soil ecosystems, which may require update of many current models of global carbon sequestration. In contrast, apparent saturation of MAOM capacity can be derived by comparing natural ecosystems with ecosystems subject to anthropogenic disturbances, and by monitoring single ecosystems on annual time scales over many years. Future research therefore needs to consider some new indicators and models to study MAOM saturation.

Dr. Song Xiaojun, a postdoctoral researcher at the Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, is the first author of this paper, with Researcher Wu Xueping, Associate Researcher Wu Huijun, and Researcher He Ping as co-corresponding authors. This research was supported by the State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, the National Key Research and Development Program, the China Postdoctoral Science Foundation, and the Technological Innovation Project of the Chinese Academy of Agricultural Sciences.

Citation and Original Link:

Song, X., Wu, H., Li, S., He, P., Wu, X., 2025. The need to update and refine concepts relating to mineral-associated organic matter saturation in soil. Soil Biology and Biochemistry 202, 109672. doi:10.1016/j.soilbio.2024.109672

Original Link: 

https://doi.org/10.1016/j.soilbio.2024.109672