A saturated buffer is an edge of the field practice that diverts water from a tile outlet to a perforated pipe that runs parallel to a stream or ditch. A control structure is installed to restrict outflow and raise the water table in the saturated zone between the stream and the crop production area. The saturated buffer zone acts as a filter to remove excess nutrients from the tile water.
Comparisons of inflow and outflow samples from saturated buffers in the Middle Cedar show a 39% reduction in nitrate concentration.
Photos for the gallery below were taken by Joe Murphy, Senior Communications Manager for the Iowa Soybean Association.