Surface Bulk Density Distribution Across Forest and Grassland Loess Catenas in the Shawnee Hills.

Surface soil bulk density is sensitive to environmental changes and land use, and links mass to volume for other soil components. Consequently, effects of environment and management on soil can be considered in both space and mass. This work considers bulk densities as comparators of management and environmental effects. Surface soil bulk densities (1-7 cm depth) were measured across landscape positions on three matched (forest and grasslands) pairs of managed watersheds as a part of watershed-based soil landscape studies that are on-going in the Shawnee Hills region of Illinois, Indiana, and Kentucky, located within MLRA 120 (Kentucky and Indiana Sandstone and Shale Hills and Valleys) and a small portion of MLRA 115B (Central Mississippi Valley Wooded Hillslope). The six watersheds comprising the sample area of the Shawnee Hills Loess Catenas Project share parent materials and mutual land use characteristics and objectives, thus creating a unique opportunity to study interactions of pedogenesis, water movement, and landscape with management practices on a watershed scale. To this end, Order 1 watersheds were delineated based on landscape position, and a minimum of 10 randomly generated points at each landscape position were selected for surface bulk density analysis. Bulk density was determined in duplicate at each point using the core method. Data were checked for normality and homogeneity of variance, and analyzed as a three (Indiana, Illinois, or Kentucky) x two factor (forest or grassland) repeated measures (landscapes) design with imbalanced data. Forest was associated with lighter bulk density compared to grasslands.