Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/4/2004
Publication Date: 11/4/2004
Citation: Zaimes, G.N., Schultz, R.C., Isenhart, T.M., Mickelson, S.K., Kovar, J.L., Russell, J.R., Powers, W.P. 2004. Influence of Land-use Practices on Stream Bank Erosion in Iowa [CD-ROM]. In: ASA-CSSA-SSSA Annual Meeting Abstracts, Oct. 31-Nov. 4, 2004, Seattle, WA.
Technical Abstract: In incised streams, bank erosion can account for 80% of sediment and 55% of phosphorus in streams. Both sediment and phosphorus are major non-point source pollutants. In Iowa annual row-crop agriculture and continuous grazing have altered the hydrologic cycle and accelerated stream incision and bank erosion. The influences of continuous, rotational and intensive rotational grazing on bank erosion are being compared to reaches, with pastures with the stream excluded, riparian forests, grass filters and annual row cropping up to the edge of the stream. Rotational and intensive rotational systems consist of numerous paddocks that provide pastures with rest time between grazing events that should lead to more stable stream banks. Bank erosion should decrease in the following order: row-cropping, continuous grazing, rotational grazing, intensive rotational grazing, pastures with stream excluded, grass filters and riparian forests. Bank eroding areas were estimated by surveying the height and length of the eroding sites of each treatment. To estimate bank erosion rates, erosion pins were measured every season except winter. Soil cores were taken for the stream banks to estimate bulk density and total phosphorus. Preliminary results suggest intensively rotated pastures and ones with stream excluded can decrease sediment and phosphorus losses from bank erosion compared to continuously grazed and row cropped sites, although grass filters and riparian forests are the most effective.