Objective The aeolian sandy soil in western Jilin province is characterized by poor structure, organic carbon deficiency, susceptibility to wind and water erosion, and low crop yield, which severely restrict sustainable agricultural development. This study explores effective approaches to improve aeolian sandy soil fertility, enhance soil erosion resistance, and increase crop yield through co-application of organic materials.

Methods Using Sorghum bicolor as the test crop, seven treatments were established: no organic application (CK), straw return (G), straw + manure (GF), manure (F), straw + microbial agent (GS), microbial agent (S), and manure + microbial agent (FS). Soil aggregate stability, active organic carbon fractions, and crop yield in the aeolian sandy soil were measured under different combined organic material treatments, followed by principal component and correlation analysis.

Results 1) GF treatment increased the content of water-stable macroaggregates ≥ 0.25 mm (R_0.25) and the mean weight diameter (M_WD) by 12.11% and 55.6%, respectively. 2) Soil organic carbon (SOC) and its active fractions significantly increased. GF treatment exhibited the greatest increases in SOC, particulate organic carbon (POC), and easily oxidizable organic carbon (EOC), while GS treatment significantly increased dissolved organic carbon (DOC). M_WD, geometric mean diameter (G_MD), and R_0.25 showed high consistency in loading vectors with SOC and POC, all closely distributed along the positive direction of PC1. 3) POC was highly correlated with aggregate stability indices M_WD, G_MD, and R_0.25, with correlation coefficients of 0.90, 0.96, and 0.93 (P < 0.05), respectively. 4) In terms of crop yield, GF treatment significantly increased S. bicolor yield by 104.0% compared to CK.

Conclusions The co-application of straw and sheep manure (GF) effectively promotes macroaggregate formation, enhances organic carbon sequestration, and improves soil resistance to wind and water erosion through a synergistic mechanism where ''slow-release carbon from straw builds the framework, and fast-release carbon from manure provides cementation.'' This approach achieves high crop yield and represents an optimized management model for the region, integrating soil improvement, carbon sequestration, and yield increase benefits.