Observations of soils at the hillslope scale in the Clear Creek Watershed in Iowa, USA

Abstract

Precipitation has long been recognized as a critical, active agent of soil formation (eg, Jenny, 1941, Amundson et aI., 2004) with the caveat that actual pedogenesis is driven by the internal behavior of water, not precipitation per se (Schoeneberger and Wysocki, 2005; Lin, 2003; Nordt et aI., 2006). Even small differences in water behavior can significantly alter morphological properties such as redoximorphic features, thickness of epipedons, expression of subsurface horizons, etc.(Lin et aI., 2007; Jarvis, 2007; Presleyet aI., 2004). Soil surveyors often map this variability using catena-based soil series (Legros, 2006; Schoeneberger and Wysocki, 2005; Lin et aI., 2005), although these same authors note that quantifying hillslope-scale water behavior is central to improving soil maps. They further note the integration of land use impacts on soils and water will be especially valuable for the effective use of natural