Denitrification in a Grassed and a Wooded, Valley and Ridge, Riparian Ecotone
1996
Schnabel, R. R. | Cornish, L. F. | Stout, W. L. | Shaffer, J. A.
Dentrification is one of the major mechanisms responsible for changes in NO⁻₃-N concentrations in shallow groundwater as subsurface flow passes from agricultural fields to the stream. In this study, denitrification is examined in a grassed and wooded riparian ecotone common to the Valley and Ridge physiographic province in Pennsylvania. Denitrification rates of 102 and 10 µg N kg⁻¹ soil d⁻¹ were measured using soil slurry and intact core incubation techniques, respectively. The grassed riparian site exhibited greater denitrification rates than the wooded site. Carbon amendments resulted in an increase in denitrification at the wooded site and suggest that denitrification may be C limited at this site. Denitrification generally decreased with distance away from the stream and also decreased with depth in the soil. Patterns of denitrification measured with the soil slurries corresponded closely to patterns of soil NO⁻₃ content.
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