Soil Characteristics that Regulate Soil Reduction and Methane Production in Wetland Rice Soils

Abstract

AbstractMethane production in soil is a microbiological process that occurs under strict anaerobic conditions. A laboratory incubation study was conducted using 10 wetland rice (Oryza sativa L.) soils from the Philippines to establish soil characteristics that govern the redox characteristics and CH4 production of soils upon wetting. Labile soil organic matter in the Ap horizon was quantified as enrichment of C and N and non‐clay‐protected C and N fractions. The C/N ratio of the enriched fraction controlled the rate of reduction upon flooding, whereas the buffering capacity, measured as extractable Fe3+ content, controlled the reduction capacity for the soils. Methane production was influenced both by the reduction characteristics of the soils and labile organic substrates.