Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/28/2011
Publication Date: 4/25/2012
Citation: Brauer, D.K., Brauer, D.E., Looper, M.L., Burner, D.M., Pote, D.H., Moore Jr, P.A. 2012. Effects of the establishment of a forested riparian buffer and grazing on soil characteristics. Communications in Soil Science and Plant Analysis. 43(9):1332-1343. Interpretive Summary: Poultry litter applications to pastures can result in high soil phosphorus (P) levels, increased P runoff and degraded surface water quality. New grassland management protocols that reduce the risk of P movement to surface water are needed. ARS scientists from Booneville and Fayetteville, Arkansas, and Bushland, TX investigated the effects of grassland management on soil characteristics receiving poultry litter. By the end of 4th year, soil concentrations of P and bulk density had increased significantly in the areas receiving poultry litter and grazed by cattle. The soil collected from a buffer had lower soil bulk densities and P concentrations. These results indicate that newly established buffer areas have soil properties that would decrease P runoff from pastures.
Technical Abstract: Poultry litter applications to pastures can result in relatively high soil phosphorus (P) levels, which in turn can contaminate runoff and degrade surface water quality. New management protocols for temperate grasslands are needed to reduce the risk of P transport to surface water. The effects of three land use treatments on soil characteristics related to P runoff were investigated using small watersheds with 8% slope near Booneville, Arkansas, USA. The land use treatments were: 1) haying of bermudagrass overseeded with winter annual forage (ryegrass or rye); 2) rotationally grazed; and 3) rotationally grazed with 12 m wide tree buffer on the downhill portion of the plot. Plots and trees were established in 2003. Annual spring application of poultry litter (5.6 Mg / ha) to the hayed or grazed portions of the plots was started in 2004. Grazing treatments were imposed shortly after. By the summer of 2008 (4 years of treatments), soil concentrations of Bray 1 extractable P and soluble reactive P had increased significantly from approximately 40 and 4 mg P / kg soil, respectively, to over 200 and 30 mg P / kg soil, respectively, in the areas of the plots receiving poultry litter. Soil bulk density in the portions of the plots being grazed had increased significantly also. The soil collected from the forested riparian buffer in 2008 had similar soil bulk densities and Bray 1 extractable P concentrations as the plots did in 2003 before treatments were imposed.