Harmonized World Soil Database
http://www.iiasa.ac.at/Research/LUC/luc07/External-World-soil-database/HTML

The Harmonized World Soil Database is a 30 arc-second raster database with over 15000 different soil mapping units that combines existing regional and national updates of soil information worldwide… with the information contained within the 1:5 000 000 scale FAO-UNESCO Soil Map of the World. Useful in determining current and future land productivity, carbon storage and sequestration potential of the world’s soils as well as land and water limitations, risks of land degradation and soil erosion risks. This has been added to Agriculture Resources Subject Tracer™ Information Blog. This has been added to Reference Resources Subject Tracer™ Infomation Blog.