Soil organic carbon (SOC) is essential for the productivity of agroecosystems and for mitigating climate change. Because the SOC contents of sandy soils are usually small, the effects of agricultural management upon SOC stocks in such soils have been insufficiently studied. In West sub-arid Africa, the coarse-textured soils (mostly Arenosols) are diversely managed by smallholders. In this study, we aimed to quantify SOC stocks in cultivated soils of that region, in a context where agricultural practices rely mainly upon organic inputs derived from various integrated crop-livestock systems. SOC stocks were estimated for the 0–30 cm depth in 1,813 plots in Senegal’s groundnut basin. We found that SOC stocks in farmers’ fields varied between 2.3 and 59.8 Mg C ha^-1 (mean ± standard deviation, 14.6 ± 0.14 Mg C ha^-1). SOC stocks were influenced slightly by soil type, but were only weakly correlated to soils’ clay and silt contents. SOC stocks differed significantly among the three studied village territories due to contrasting livestock-raising systems. Average stocks were significantly higher in plots close to housings (home-fields), which receive larger amounts of organic inputs, than in plots farther from the village (out-fields). Thus, the organic inputs to home-fields improves soil C stocks of these sandy soils in the short term. Innovative agricultural practices in the studied area probably need to target options for managing all fields optimally. Those options will require continuous application of organic products—a measure that will in turn require solutions for improving availability or management of local organic resources.

土壤有机碳 (SOC) 对于农业生态系统的生产力和减缓气候变化至关重要。由于沙质土壤的 SOC 含量通常很小，因此尚未充分研究农业管理对此类土壤中 SOC 储量的影响。在西部亚干旱非洲，小农对质地粗糙的土壤（主要是 Arenosols）进行多样化管理。在这项研究中，我们旨在量化该地区耕作土壤中的 SOC 储量，在这种情况下，农业实践主要依赖于来自各种综合作物畜牧系统的有机投入。对塞内加尔花生盆地 1,813 个地块中 0-30 厘米深度的 SOC 储量进行了估计。我们发现农民田间 SOC 储量在 2.3 到 59.8 Mg C ha ^-1（平均值±标准差，14.6 ± 0.14 Mg C ha^-1）。SOC 储量受土壤类型的影响轻微，但与土壤的粘土和淤泥含量仅微弱相关。由于牲畜饲养系统不同，三个研究村庄的 SOC 存量存在显着差异。与离村庄较远的地块（外地）相比，靠近房屋的地块（家庭田地）的平均存量显着更高，这些地块获得了更多的有机投入。因此，家庭田地的有机投入在短期内改善了这些沙质土壤的土壤碳储量。研究区域的创新农业实践可能需要针对优化管理所有田地的选项。这些选择将需要有机产品的持续应用——这一措施反过来又需要解决方案来改善当地有机资源的可用性或管理。