The objective of this study was to evaluate the soil organic carbon stock and litter mass in silvopastoral systems (SSP) implemented with Urochloa decumbens and different Eucalyptus spatial arrangements. The SSP was implemented in 2008 with the spatial arrangements of (3 × 2) + 20 m (434 trees ha⁻¹), (2 × 2) + 9 m (909 trees ha⁻¹) and 9 × 2 m (556 trees ha⁻¹) formed by the Eucalyptus cultivars GG100, I144 and VM 58. Soil samples at 0 to 20 and 0 to 40 cm depths were collected in SSP in 2011 and 2015 to determine soil organic carbon stock. The soil organic carbon stock was 38.5% higher in 2015 compared to 2011 (111 vs. 80.7 Mg ha⁻¹), which represented an annual sink of 6.22 Mg ha⁻¹ and indicates an increase in carbon stock over years. Litter mass was greater under the canopy than between trees, probably due to the greater drop in biomass in this location. The silvopastoral systems showed similar volumes of litter and soil organic carbon, which indicates that the evaluated arrangements have similar capacities to store carbon.

本研究的目的是评估采用斜卧尾草和不同桉树空间排列实施的林牧系统（SSP）中的土壤有机碳储量和凋落物质量。SSP于2008年实施，空间布局为(3 × 2) + 20 m (434棵树 ha ⁻¹ )、(2 × 2) + 9 m (909棵树 ha ⁻¹ ) 和 9 × 2 m (556棵树ha ^-1）由桉树品种GG100、I144和VM 58形成。2011年和2015年在SSP中采集0至20和0至40 cm深度的土壤样品以确定土壤有机碳储量。与 2011 年相比，2015 年土壤有机碳储量增加了 38.5%（111 比80.7 Mg ha ⁻¹），这意味着年汇量为 6.22 Mg ha ⁻¹，表明碳储量逐年增加。树冠下的凋落物质量大于树间的凋落物质量，这可能是由于该位置的生物量下降幅度更大。林牧系统显示出相似数量的枯落物和土壤有机碳，这表明所评估的布置具有相似的碳储存能力。