Supplementary material/Organic carbon dynamics in clay soils: impact of management practices on microorganism structure and abundance under semi-arid conditions

Proper management of soil organic matter in arid and semi-arid regions improves organic carbon storage in the soil, helps in compact soil degradation, and mitigates climate change impacts, and preserves ecosystem functionality and sustainability food security. This study aims to provide a better insight into the biogeochemical processes that drive the organic carbon dynamics of saline clay soil in a semi-arid climate. The study is not intended to be exhaustive but contributes to analyzing the relationship between bacterial microflora, physicochemical properties, and organic carbon dynamics as a function of different soil management modes. The monitoring was carried out on three different plots located at the National Institute of Agronomic Research of Algeria. A physicochemical characterization of the soils was performed. A metagenomic study was also conducted to identify bacterial biodiversity using PCR-amplified DNA sequencing. The study results show that the control plot has the highest average organic carbon stock value at 47 Mg ha^-1. This was followed by the amended plot and the conventional plot, respectively, with 43 Mg ha^-1 and 38 Mg ha^-1. In the context of this study, organic carbon dynamics would appear to depend on the interaction of several biotic and abiotic factors. Soil management methods would impact the density and diversity of bacterial microflora. This, in turn, affects the soil's physicochemical properties and, more specifically, organic carbon dynamics and storage.干旱与半干旱地区的土壤有机质合理管控，可提升土壤有机碳储量，缓解土壤紧实退化问题，减缓气候变化影响，同时维护生态系统功能与可持续粮食安全。本研究旨在深入解析半干旱气候下盐渍黏壤土有机碳动态的驱动生物地球化学过程。本研究并非追求全面详尽，而是旨在剖析不同土壤管理模式下，细菌微生物区系、土壤理化性质与有机碳动态之间的关联。监测工作在阿尔及利亚国家农业研究院（National Institute of Agronomic Research of Algeria）的三块不同试验田开展。研究人员对供试土壤完成了理化性质表征，并采用聚合酶链式反应（PCR）扩增DNA测序的宏基因组学手段，鉴定细菌生物多样性。研究结果显示，对照田的平均有机碳储量最高，达47 Mg·ha⁻¹；改良田与常规田依次次之，分别为43 Mg·ha⁻¹与38 Mg·ha⁻¹。本研究表明，有机碳动态似乎受多种生物与非生物因子的交互作用调控。土壤管理方式会影响细菌微生物区系的丰度与多样性，进而作用于土壤理化性质，更具体地说，会影响有机碳动态及其储量。