Influence of nitrate on methane production and oxidation in flooded soil

Abstract
Methane (CH4) production in paddy soils and sediments as influenced by nitrate (NO3) addition was studied under a closely controlled soil pH and oxidation‐reduction (redox) potential (Eh) conditions. CH4 production was affected by soil pH and NO3 . Added NO3 reduced the amount of CH4 produced of each pH level studied. Nitrate addition primary effect in reducing CH4 production was through the resultant increase in soil redox potential (Eh). Using Methyl Fluoride (MF), a CH4 oxidation inhibitor we found that added NO3 was not used in CH4 oxidation by methanotrophic bacteria.