The GIS-based soil information used for creating the tall fescue suitability maps in this chapter (pH, drainage, and salinity) was obtained for the United States from the USDA-NRCS (2006a) and for China from the Chinese Academy of Agricultural Sciences and Institute of Soil Science, the Chinese Academy of Science, Nanjing (Shi et al., 2004). Mean pH, salinity, drainage, and available water layers, at a resolution of 1:1,000,000 (1:1M), are viewable at the Internet Mapserver application described by Doggett et al. (2005).
The 1:1M database of China consists of two data sets - "Soil Series of China, vol. 6" from the National Soil Survey Office and "Soil Series of Selected Provinces" with information on 2540 soil series from throughout China - that are described by Shi et al. (2004). The soil series records were taken from a set of 30,000 profile descriptions collected as part of the Second National Survey (Shi et al., 2004). This survey resulted in the creation of a 1:1M scale map for China (Shi et al., 2006).
The second data set used for the maps described in this chapter is the digital version of the 1:1M scale soil map of China. A GIS was used to link the 1:1M scale soil map to the profile attribute information based on the Genetic Soil Classification of China (Shi et al., 2004). The classification of "soil family" is used as the basic map unit, for which there are 909 entries. In total there are approximately 94,000 polygons for the country, of which there are 235 soil subgroups, 61 soil great groups, and 12 soil orders. The original form of the map was a series of provincial hardcopy maps. The map exists now as a single digital database, which includes all the original detail (Shi et al., 2006).
Digital soil information for other regions of the world is available from various sources, including FAO (http://www.fao.org/AG/agl/agll/prtsoil.stm, verified 19 Mar. 2010), UNEP (http://na.unep.net/datasets/datalist.php, verified 19 Mar. 2010), International Society of Soil Science, and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), albeit in various formats and resolution levels.