ARS | Publication request: DENITRIFICATION POTENTIAL OF SOIL IN A RIPARIAN ZONE AND A SWINE WASTEWATER SPRAY FIELD AS MEASURED BY DENITRIFICATION ENZYME ANALYSIS

Submitted to: International Symposium on Biogeochemistry of Trace Elements Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 12, 1999
Publication Date: N/A

Technical Abstract: Nonpoint source pollution of streams from excess nitrogen is a general agricultural problem, and its control is particularly difficult in areas of intense animal waste applications. Streams contamination in such areas can be reduced by use of riparian zones. The objective of this investigation was to assess the relative denitrification potential (DP) of soils at various depths and positions in transects from the edge of a swine wastewater spray field through a Coastal Plain riparian zone. Soil samples were taken from three depths at four locations along two transects during four seasons of the year over a three-year period. Four treatments were used - the control, nitrate addition, carbon addition, or carbon and nitrate additions. The DP was lowest near the field edge, but it varied within the riparian zone. It was highly correlated to the total kjeldahl nitrogen of the soil. It decreased with depth for all treatments. It was highest in the summer. Carbon was not a limiting factor for DP in any of the locations or depths, but nitrate was a common limiting factor in the riparian zone.