Evaluating Cover Crops (Oats, Sudex and Sunn hemp) for the Control of Soil Erosion and Associated
Sediment Loading in a Hawaiian Watershed. (6439)
Authors:
M. Ryder* - University of hawaii A. Fares - University of Hawaii V. Polyakov - University of Hawaii
Abstract:
Cover crops minimize erosion by protecting the soil surface, slowing runoff and increasing infiltration. The objective of this study was to gage the effectiveness of three cover crops (sunn hemp, oats and sudex) at reducing surface runoff and sediment concentrations as compared to fallow treatment. The study site was on 8-12% sloping Ewa silty clay soil bordered by a gulch. Ten meter long treatment plots were replicated three times and randomly planted within the treatment layout.
Runoff collectors were installed and rainfall was recorded using a tipping bucket rain gage. Additional soil chemical and physical data were collected from the site.
Surface water samples were collected after all runoff generating rainfall events and analyzed for total suspended and total dissolved sediments. The experimental results support the hypothesis that cover crops, in comparison with fallow plots, substantially decreased the soil erosion, sediment loading and improved surface water quality. Cover crops decrease the suspended solids by 25-94% as compared with the fallow treatment. The treatment means showed a decrease in suspended solids of 63%, 79% and 54% for sunn hemp, oats and sudex, respectively. The results for dissolved solids show minor differences between treatment that are not statistically significant. However, the data show a trend of increasing dissolved solids in runoff from the cover crop treatments.
Speaker Information: Micah Ryder, University of hawaii, 1910 east-west road, honoluluq, HI 96822; Phone: 808 956-6361; E-mail: [email protected]
Session Information: Tuesday, November 2, 2004, 9:55 AM-11:30 AM Presentation Start: 11:00 AM
Keywords: erosion; surface runoff; sediment; cover crops
