Nonbiological Nitrous Oxide Production from Vadose Soil Catalyzed by Galvanized Steel Tubing

Abstract

AbstractStudies of microbial processes in the vadose zone are hampered by difficulties in obtaining uncontaminated samples. We initiated a study in 1985 to quantify microbial denitrification in the vadose zone of agricultural land located in the Atlantic Coastal Plain. In the initial stages of this study, deep soil cores (360 cm) were collected and subcored with sterile galvanized steel tubes to eliminate contamination by surface soil. We observed N2O production from subsoil incubated with C2H2 in galvanized tubes, but in the same soil incubated anaerobically with added glucose and NO−3, denitrification activity was not detected. Subsequent comparisons of N2O production in surface and subsurface soil incubated in galvanized and plastic tubes indicated that chemodenitrification was the likely mechanism responsible for the N2O production observed in soil contained in galvanized steel tubes. These results suggest that, in field or laboratory experiments designed to investigate soil‐N transformations, galvanized steel enclosures should be used with caution.