Identification of regional soil quality factors and indicators: II. Northern Mississippi Loess Hills and Palouse Prairie

Diversity of soil series present in a region may hinder identification of s oil quality factors and indicators at a regional scale. Our objectives were (i) to identify soil quality factors for a diverse population of soils at the regional scale, (ii) to determine which factors vary significantly with land use, (iii) to select indicators from these factors that can be used w ith the National Resource Inventory (NRI) for monitoring soil quality, and (iv) to compare these results to a similar study involving only a single So il series. One hundred eighty-six points representing 75 soil series in the Northern Mississippi Valley Loess Halls and 149 points representing 58 son series in Palouse and Net Perce Prairies were sampled from a statistically representative subset of NRI sample points and analyzed for 20 soil attrib utes. Factor analysis was used to identify soil quality factors and discrim inant analysis was used to identify factors and indicators most sensitive t o land use within each region. In the Northern Mississippi Valley Loess Hil ls, five soil quality factors were identified. Discriminant analysis select ed potentially mineralizable N (PMN), microbial biomass C (MBC), warier sta ble aggregates (WSA), and total organic C (TOC) as the most discriminating attributes between land uses. In the Palouse and Net Perce Prairies, six fa ctors were identified. Discriminant analysis selected TOC and total N as th e most discriminating attributes between land uses. The soil quality factor s were similar among three of the four regions, but TOC was the only indica tor common to all regions for distinguishing among land uses.