Figure 10. Nitrate-nitrogen concentration in shallow groundwater expressed as a percentage of maximum concentration (concentration at field edge). Nitrate reduction through the buffer is believed to be due primarily to denitrification occurring in the riparian zone close to the streambank.
Riparian buffers reduce nitrate-nitrogen concentrations entering a stream from shallow groundwater flow

Data taken from Jordan et al., 1993 (MD); Lowrance, 1992 (GA), Peterjohn & Correll, 1984 (MD); Jacobs & Gilliam, 1985 (NC); Buffington, 1993 (NC).