Differentiated Carbon Stabilization Pathways Reveal Cropland Promotes <scp>MAOC</scp> in the Yellow River Sediment‐Affected Area

ABSTRACT Soil organic carbon (SOC) fractions play a crucial role in regulating biogeochemical cycles and carbon sequestration processes. However, in ecologically fragile regions such as the Yellow River sediment‐affected area, the long‐term dynamics and turnover mechanisms of particulate organic carbon (POC) and mineral‐associated organic carbon (MAOC) under different land‐use types remain unclear. Based on the 2013 and 2023 field samples, we examined planted forests, cropland, and orchard soils in the Yellow River sediment‐affected region to quantify 0–40 cm soil layer decadal changes in POC and MAOC, their sequestration pathways, and key drivers. All land‐use types exhibited significant carbon accumulation but followed differentiated sequestration pathways. In cropland, the increase in MAOC (2.17 g kg −1 ) in the 0–20 cm layer was 2.1 times that of POC (1.03 g kg −1 ), and the proportion of MAOC increased markedly from 43% to 51%. Orchard soils exhibited the highest MAOC accumulation in the surface layer (3.63 g kg −1 ) but showed a loss of POC in the 20–40 cm layer (−0.91 g kg −1 ). Planted forests showed steady increases in both POC and MAOC. Analysis of driving factors revealed that vegetation inputs and soil properties were key determinants of surface POC dynamics, while soil properties, particularly total nitrogen content and soil particle size, primarily controlled MAOC stabilization. This study demonstrates that modern agricultural practices characterized by straw incorporation effectively promote the conversion of labile POC into stable MAOC, providing key scientific evidence to optimize land management and enhance soil health and carbon sequestration efficiency in coarse‐textured soils.