DENITRIFICATION IN CLAYEY TILL

Denitrification in core samples from oxidized and unoxidized clayey till was studied by analyzing N2O production with time. In general, low rates of denitrification were observed. Some subsamples of cores, however, yielded anomalously high rates of denitrification. Statistical analyses of the data from the oxidized (n = 183) and unoxidized (n = 85) tills did not allow reliable potential rates of denitrification to be. estimated. The lack of reliable estimates of rates can be attributed to inherent heterogeneity critical factors controlling denitrification between subsamples. Such heterogeneity was significantly less in unoxidized till than in oxidized till. Higher denitrifying activity appeared to be localized in diverse microsites along fractures and adjacent to organic matter.