Improving Soil and Water Quality with Riparian Buffers
The agricultural landscape has four major sources of non-point source (NPS) pollutants. These are: 1) surface and subsurface runoff which carry sediment and agricultural chemicals to streams; 2) eroding streambanks which can contribute more than fifty percent of the sediment load to the stream; 3) field tile drains which contribute the highest concentrations of soluble agricultural chemicals to streams; and 4) livestock grazing of streamside or riparian areas which contribute to bank instability and add animal waste and pathogens to the water. Maintaining or establishing a forested or prairie buffer along streams and rivers provides more than just a beautiful landscape. While a considerable body of evidence confirms that existing vegetated streamside zones can be effective sinks for NPS pollution (Castelle et a!. 1994, Osborne and Kovacic 1993, Lowrance 1992, Cooper eta!. 1987, Jacobs and Gilliam 1985, Lowrance eta!. 1985, 1984, Peterjohn and Correll 1984), little information is available for restored or constructed streamside buffer systems. Designing and establishing the right combination of native trees, shrubs and grasses as buffer strips and integrating them with constructed wetlands, soil bioengineering and rotational grazing can improve water quality.