Management of Forested Filter Zones for Dispersion and Treatment of AgriculturalRunoff

摘要

Trenched level spreaders were designed to disburse agricultural runoff at theupper end of a forested filter zone to enhance the effectiveness of the zone in removing sediment and nutrients from agricultural runoff. Effeciveness of trenched level spreaders was tested in two field-edge forested filter zones in the lower Piedmont of North Carolina. The most adequate of the two zones, with dispersed stormflow, removed 46% to 73% of all pollutants tested during the 4-year period of the study. Dispersed of stormflow drastically improved removal of suspended sediment, ammoniacal nitrogen, and orthophosphate, but only slightly improved, or did not affect removal of nitrate and total Kjeldahl nitrogen, and total phosphorus. This technology is recommended as an agricultural BMP around tilled fields, and should be effective on roadways and construction sites.