Tracing decomposition of organic carbon sources can balance carbon budget and reduce soil erosion targetedly. However, tracers may provide inaccurate source information, possibly due to the instability of organic matter under different land use types. Little is known about which stable tracer to choose based on different erosion scenarios. We, therefore, evaluated the availability of three commonly-used tracers techniques (i.e., bulk stable isotopes, fluorescence proxies and stoichiometric ratios) under different mixed end-members (i.e., Woodland, arable land and grassland) via a laboratory-scale controlled experiment. Combining fluorescence excitation emission matrix (EEM)-parallel factor analysis (PARAFAC), Bayesian isotope mixing model and three evaluation criteria. Bulk stable isotopes (δ¹³C, δ¹⁵N) were considered to be the most suitable tracers for terrestrial organic matter sources tracing (Most of the R² > 0.85, % difference < 10%), especially under Arable land-Woodland (A-W) mixed end-member, followed by traditional tracers (C/N, DOC). Unfortunately, the fluorescent indices were not suitable for terrestrial organic matter sources tracing, due to the similarities between different terrestrial organic matter sources, especially under Grassland-Woodland (G-W) mixed end-member (Most of the P-value > 0.05, % difference > 10%). Our results recommend that when selecting a tracer, not only the stability of the tracer should be considered, but also the difference among eroded organic matter sources. This study provides new insights into the validation of commonly-used tracers in identifying eroded organic matter sources accurately.

追踪有机碳源的分解可以平衡碳收支，有针对性地减少土壤侵蚀。然而，示踪剂可能提供不准确的源信息，这可能是由于不同土地利用类型下有机物质的不稳定性。关于根据不同的侵蚀情况选择哪种稳定示踪剂知之甚少。因此，我们通过实验室规模的控制实验评估了三种常用示踪技术（即体积稳定同位素、荧光代理和化学计量比）在不同混合末端成员（即林地、耕地和草地）下的可用性. 结合荧光激发发射矩阵（EEM）-平行因子分析（PARAFAC）、贝叶斯同位素混合模型和三个评价标准。体积稳定同位素 (δ ¹³ C, δ¹⁵ N) 被认为是最适合陆地有机物源追踪的示踪剂（大多数 R ² > 0.85，% 差异 < 10%)，尤其是在耕地-林地 (AW) 混合端元下，其次是传统示踪剂（C/N、DOC）。不幸的是，由于不同陆地有机质来源之间的相似性，特别是在草地-林地（GW）混合端元下（大部分 P 值 > 0.05，％差异），荧光指数不适合陆地有机质来源追踪> 10%）。我们的研究结果建议，在选择示踪剂时，不仅要考虑示踪剂的稳定性，还要考虑侵蚀有机质来源的差异。这项研究为验证常用示踪剂在准确识别侵蚀有机物来源方面的验证提供了新的见解。