Straw and nitrogen fertilization driving iron oxide transformation and soil carbon sequestration in saline paddy soils

The “enzyme latch” and “iron gate” mechanisms play essential roles in regulating soil organic carbon (SOC) cycling in coastal saline paddy soils; however, their contributions to SOC sequestration under straw incorporation and nitrogen (N) fertilization remain poorly understood. A seven-year field experiment was conducted in a coastal saline paddy soil with six treatments, including two N levels (N1: 255 kg N ha-1 and N2: 400 kg N ha-1) and three straw incorporation levels (S0: 0, S1: 4,500 kg st