Submitted to: Soil Use and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2011
Publication Date: 7/24/2011
Citation: Hass, A., Zobel, R.W. 2011. Using soil E horizon in salvaged topsoil material - effect on soil texture. Soil Use and Management. DOI: 10.111/j.1475-2743.2011.00361.x. Interpretive Summary: During construction of sites for uses from homes to factories to playing fields, top soil is removed prior to excavation. Current definitions of top soil are imprecise and lead to insufficient amounts being conserved for use during reconstruction, leading to increased expense or reduced turf sustainability. This manuscript demonstrates a top soil classification (definition) that should result in a significant increase in the amount of top soil conserved, and therefore decreased expense and increased turf sustainability.
Technical Abstract: Topsoil is a limited natural resource that needs to be efficiently salvaged during landscape reconstruction operations for its further use as topsoil. Current guidelines for borrowed topsoil define topsoil as the surface layer of native soil, or soil A horizon. Using information from nearly 8,000 soil pedons from the National Soil Characterization Database (USDA-NSSC, Lincoln NE) we simulate the mixing of A layers into their respective A master horizon, and the mixing of soil A and E horizons into a respective mixed AE horizon. Selected soil properties were compared among four different operationally defined topsoils: A surface layer, ASL; Ap surface layer, APL; A master horizon, Am; and AE mixed horizons. Significant differences were found among the distinct topsoils, with average topsoil depth in the order: AE > Am > APL > ASL; sand content in the order: ASL > AE > Am > APL; clay in the order: APL > Am > ASL > AE; and organic carbon in the order: ASL > Am > APL > AE. While excavation depth increased by 2.5 x in the AE mixed horizons compared to their A horizon counterparts, no adverse effect on soil texture was noted. Based on this study it is recommended to include the E horizon in topsoil definition for salvaging operations where soil material is excavated for further use as topsoil. Selected characteristics of the operationally defined topsoils, on a soil order basis, are tabulated.