Organic materials input promotes the soil aggregate sequestration through changing soil aggregates structure and...

The strategic application of organic amendments presents a transformative approach for enhancing agroecosystem sustainability by modulating soil hydrostructural dynamics and carbon sequestration. However, changes in soil moisture, nutrients, aggregate stability, and SOC sequestration under different organic materials type input in farmland of arid northwest China remain uncertain. In this study, an experiment with five treatments (CK: control, LB: smashed leaves and branches, CS: smashed corn stalks, HV: green fertilizer, MS: waste mushroom bran) input applied into the soil. The results indicated that organic materials input management significantly optimizes soil moisture content (SMC), soil water storage (SWS), and water use efficiency (WUE) in both soil depths, and MS treatment elevated SWS by 6.7 %-16.2 % and WUE by 23.7 % relative to CK, while stabilizing moisture fluctuations across critical maize growth stages. The electrical conductivity, soil organic matter, total nitrogen, available phosphorus, available potassium, Fe, Cu and Zn contents differed significantly under organic materials input. Organic materials input enhanced soil carbon sequestration by optimizing aggregate hierarchy, and mean weight diameter (MWD), geometric mean diameter (GMD), while MS reduced soil erodibility K factor by 12.9 %, and amplified aggregate-associated organic carbon stocks by 94.4 % at the 0-20 cm soil depth, outperforming other organic materials input treatments. Soil organic carbon content exhibited strong particle-size dependency with decreasing from >2 mm to <0.25 mm aggregates, and >2 mm aggregates conten of 39.68 %-44.12 % to SOC. Random forest analysis identified microaggregate SOC and K factor as stability drivers. The SEM model showed that the organic materials input, aggregated associated SOC contents and stocks explained 97.1 % of the variation in aggregate-associated SOC stock. In conclusion, the application of waste mushroom bran input enhances the soil aggregate stability by altering soil aggregates structure and soil carbon sequestration, thereby establishing a scientific foundation for developing soil health regulation mechanisms and advancing sustainable agricultural practices.