Stream bank erosion adjacent to riparian forest buffers, row-crop fields, and continuously-grazed pastures along Bear Creek in central Iowa

ABSTRACT:

Row-crop agriculture, continuous-grazing, and stream channelization, have accelerated stream bank erosion and increased sediment load. Stream bank erosion rates and total soil loss were compared among riparian forest buffers, row-crop fields and continuously grazed pastures along a continuous 11 km (6.8 mi) stream reach in central Iowa. Exposed erosion pins were measured to estimate stream bank erosion rates, approximately every month from June 1998 to June 1999, except during the winter months. Total stream bank soil losses for each treatment were estimated from the mean bank erosion rate, mean bulk density, and the total stream bank eroding area. Row-crop fields had the greatest stream bank erosion rate and total soil losses followed by continuously grazed pastures while riparian forest buffers had the lowest. If riparian forest buffers had been established along all of the non-buffered segments of the 11 km (6.8 mi) stream reach, total stream bank soil loss would have been reduced by approximately 72%.