LAUSR

Abstract Paddy soil indigenous N supply is often poorly related to N status and our aim was to assess its linkage to reduction of Fe3+ and Mn4+, primary terminal electron acceptors in submerged soils. Transplanted rice was grown in the greenhouse in four Bangladeshi paddy soils with distinct SOC to Feox ratio (1.6 to 4.9) for 72 days firstly under continuous and then intermittent flooding. Solution buildup rates of Fe2+ and Mn2+ in the first 2–3 weeks of flooding correlated negatively with soil organic carbon (SOC) to NH4-oxalate extractable Fe (Feox) and Mn (Mnox) ratios (p  50% of e− capture, though. Reduction of abundantly present octahedral Fe3+ in chlorites and vermiculite and their interstratified forms in these floodplain silty Inceptisols is hypothesized to also support microbial activity. Notwithstanding, a close temporal synergy existed between solution Fe and soil mineral N and their build-up rates were correlated (r: 0.77 to 0.90; p