Naturally occurring riparian filter strips are widely recommended as a technique for removing chemicals from flow prior to entering a stream. Data on their effectiveness is sparse as is information on the partitioning of chemicals trapped byvarious mechanisms in these strips. Studies were conducted on the effectiveness of natural riparian grass buffer strips in removing sediment, atrazine, nitrogen and phosphorus from surface runoff The strips were located in a karst watershed. No-till andconventional-tillage erosion plots served as the sediment and chemical source area. Runoff from the plots was directed onto 4.57, 9.14, and 13.72 m filter strips where the inflow and outflow concentrations and flow rates were measured. Trappingpercentages for sediment and chemicals typically ranged above 90. An evaluation was made of the distribution of trapped chemicals among infiltrated mass and mass stored in the surface layer The analysis showed that most of the chemicals were trapped byinfiltration into the soil matrix and that trapping efficiency increased with filter stip length and with fraction of water infiltrated.
展开▼
