Scaling up and Scaling Down in a Major Land Resource Area (MLRA) Soil System Study.

Major Land Resource Area (MLRA) soil systems research is designed to address pedological processes at the regional MLRA level, landscape, landform and landform component levels. This scalability is critical for the next generation of soil survey if we are to meet the present and future needs of conservation and land management. The Shawnee Hills Loess Catenas MLRA Soil System Study was designed to address the pedological processes at the various scales in MLRA's 120 and 115 that cover about 9,700,000 hectares. Six small catchments varying in size from 5 to 9 hectares represent the major soil systems. The small catchments are paired to represent forest and pasture major land uses in Kentucky, Indiana, and Illinois. They represent the dominant loess thicknesses sequence that varies from 1.5 m in Kentucky to 2.5 m in Indiana and > 4 m in Illinois. The soil-landscape systems approach is a unifying concept that (i) relates  regional soil spatial, digital, and pedon data, (ii) allows for upscaling and downscaling of soil properties and pedological process and (iii)expands the scope and scale of traditional soil survey. This approach adds value and utility to the existing soil survey products by: documenting important and extensive MLRA benchmark soil-systems; improving the accuracy and precision of soil maps, soil-landscape block diagrams and soil series concepts; providing hands-on field experience in the study of soil systems at various scales; and facilitating the systematic collection of  data that can be entered into the National Soil Survey Information System (NASIS) to improve soil interpretations.