Effect of reduced mineral fertilization (NPK) combined with green manure on aggregate stability and soil organic carbon fractions in a fluvo-aquic paddy soil

Abstract A 10-year field experiment with different inorganic fertilizer rates, NPK (F; 100 %, 80 % and 60 %) supplemented with Chinese milk vetch, Astragalus sinicus L. (MV; 15 t ha−1, 22.5 t ha−1, 30 t ha−1 and 37.5 t ha−1) as green manure was conducted in a fluvo-aquic paddy soil in Southern China. The study aimed to assess soil water stable aggregates (WSA) and their stability indices, aggregate associated SOC and physical protection mechanisms of SOC within aggregate associated density fractions (fLOC, c-iPOC, f-iPOC and mSOC) at 0−20 cm soil depth. The results showed that soil macroaggregation was significantly improved (P