Wednesday, November 15, 2006 - 11:15 AM

Soil Spatial Variability on the Wabash End Moraine, Indiana.

Hans Winzeler, Phillip Owens, Brad Lee, Javed Iqbal, and Kelli Hart. Purdue Univ, 1602 Evans Ave, Valparaiso, IN 46383

The Wabash Moraine is one of several concentric end moraines in northeastern Indiana. Soils there are developed in dense calcareous glacial till and are high in illitic clay. Spatial variability of soil properties was examined on a 3.5 ha field on the Moraine in a 20 m grid-sampling scheme. Examined properties included texture, chemical properties, depth of soil development, bulk density, depth to platy structure, elevation, and slope. Soil properties exhibited predictable patterns based on landscape position, elevation, and slope. Soil development was deeper in areas experiencing greater water energy influx due to slope position and was evident by depth to presumably plant-induced heightened acidity, depth to unweathered glacial till (characterized by massive or platy texture), and depth to high-level calcium carbonates (which are leached from the soil horizon with weathering through time). Results indicate that slope and landscape position can be valuable compliments to a grid sampling strategy and that strong correlations exist between slope/landscape positions and observed soil properties. Grid sampling strategies that include a slope/landscape position component should be more reliable as descriptive tools of soil variability than grid sampling approaches that do not include slope/landscape position values.