Global soil informaiton

• Global Soil Regions Map
  by the Natural Resources Conservation Service U.S. Department of Agriculture
  http://soils.usda.gov/use/worldsoils/mapindex/order.html
  Free, downloadable; a 2 minute grid cell resolutions; Production Date: April, 1997 Revised: September, 2005. Geographic Coverage: Global; Minimum Scale: 1:5,000,000.
  
  
• World soil information
  by International Soil Reference and Information Centre
  http://www.isric.org/NR/exeres/545B0669-6743-402B-B79A-DBF57E9FA67F.htm
  
  
• Digital Soil Map of the World and Derived Soil Properties
  by The Land and Water Development Division, FAO
  http://www.fao.org/AG/AGL/agll/dsmw.stm