Agricultural soils degradation is a global challenge that affects food security, climate change, environmental risks, and the loss of biodiversity and ecosystem services. In this on-farm study conducted in the Mediterranean mountain area of southern Spain, we used a natural area (NAT) as reference and compared the effect of three tree cropping systems – conventional olive (COL), organic olive (OLO) and organic almond (OAL)– on soil aggregation, aggregates-associated soil organic carbon and carbon preservation capacity. This was conducted to evaluate the hypothesis that the organic management system affects soil stability, soil organic carbon sequestration and soil organic carbon distribution among aggregate fractions. Soil samples were collected at five different depths (0–10, 10–20, 20–30, 30–40 and 40–50 cm depth) to analyse the management impacts on deeper soil layers. Aggregation indices showed an increase in the topsoil layers (0–10 and 0–20 cm depth) under organic managements with higher large macroaggregates (> 2000 µm) percentages in OLO (+10.9 % and 21.8 %) and OAL (+15.25 % and 28.5 %) respectively compared to COL. A significant decarbonization process was detected and the total carbon preservation capacity (0–50 cm depth) decreased from NAT (159.24 g kg^—1) to cultivated plots, that stored a − 53.8 % OLO (73.45 g kg^—1), − 66.3 % OAL (53.69 g kg^—1) and − 70.4 % COL (47.22 g kg^—1). In this regard, the management change from conventional to organic increased total carbon preservation capacity and caused a change in the distribution of soil organic carbon pool observed in a higher carbon content in large macroaggregates (+47.3 %). These findings indicate that organic farming affects not only to the soil organic carbon sequestration but also to the extent of soil organic carbon protection.

农业土壤退化是一项全球性挑战，会影响粮食安全、气候变化、环境风险以及生物多样性和生态系统服务的丧失。在西班牙南部地中海山区进行的这项农场研究中，我们使用自然区域 (NAT) 作为参考，比较了三种树木种植系统的效果——传统橄榄 (COL)、有机橄榄 (OLO) 和有机杏仁(OAL)– on soil aggregation, aggregates-associated soil organic carbon和碳保存能力。这是为了评估有机管理系统影响土壤稳定性、土壤有机碳固存和土壤有机碳在聚合部分之间的分布的假设。在五个不同的深度（0-10、10-20、20-30、30-40 和 40-50 厘米深度）收集土壤样本，以分析管理对深层土壤的影响。聚集指数显示在有机管理下表土层（0-10 和 0-20 厘米深度）增加， OLO（+10.9 % 和 21.8 %）和 OAL（+15.25 % 和28.5 % 分别与 COL 相比。检测到一个显着的脱碳过程，总碳保存能力（0-50 厘米深度）从 NAT（159.24 g kg ^-1) 到耕地，储存了 - 53.8% OLO（73.45 g kg ^-1）， - 66.3 % OAL（53.69 g kg ^-1）和 - 70.4 % COL（47.22 g kg ^-1）。在这方面，从常规到有机的管理变化增加了总碳保存能力，并导致土壤有机碳库的分布发生变化，在大型团聚体中观察到更高的碳含量 (+47.3%)。这些发现表明，有机农业不仅影响土壤有机碳固存，而且影响土壤有机碳保护的程度。