Effects of Narrow Grass Hedges on Nutrient Transport From Land Application Areas

The placement of stiff-stemmed grass hedges on the contour along a hill slope has been shown to decrease runoff nutrient transport. This study was conducted to measure the effectiveness of a narrow grass hedge in reducing runoff nutrient transport from plots with a range of soil nutrient values. Composted beef cattle manure was applied at dry weights of 0, 68, 105, 142, and 178 Mg ha-1 to a silty clay loam soil and then incorporated by disking. Soil samples were collected 243 days later for analysis of water-soluble phosphorus (WSP), Bray and Kurtz No.1 phosphorus (Bray-1 P), NO 3-N and NH 4-N. Three 30-min simulated rainfall events, separated by 24-hour intervals, were then applied. The transport of dissolved phosphorus (DP), total P (TP), NO 3-N, NH 4-N, total nitrogen (TN), runoff, and soil erosion were measured from 0.75 m wide x 4.0 m long plots. Compost application rate was found to significantly affect WSP, Bray-1 P, and NO 3-N content of the soil. The transport of DP, TP, NO 3-N, NH 4-N, TN, runoff and soil erosion was reduced significantly on the plots with a grass hedge. Mean runoff on the hedge and no-hedge treatments was 17 and 29 mm, respectively, and soil erosion rates were 0.12 and 1.48 Mg ha-1. Compost application rate significantly affected the transport of DP, TP, and NO 3-N in runoff. The experimental results indicate that stiff-stemmed grass hedges, planted at selected down slope intervals, can significantly reduce the transport of nutrients in runoff from areas with a range of soil nutrient values. The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agricultural and Biological Engineers (ASABE), and its printing and distribution does not constitute an endorsement of views which may be expressed. Technical presentations are not subject to the formal peer review process by ASABE editorial committees; therefore, they are not to be presented as refereed publications. Citation of this work should state that it is from an ASABE meeting paper.