The FAO/UNESCO soil map of the world was prepared using the topographic map series of the American Geographical Society of New York at a nominal scale of 1:5,000,000 consisting of a 30 cm topsoil layer, and a 70 cm subsoil layer.
The provided soil map has the “WGS-84 Spatial reference” without any projection.
The users will have to project this map before using in ArcSWAT or QSWAT.
Associated files include: “Lookup_Soil_FAO-UNESCO.txt”, and “SWAT2012.mdb”.

Download related article from “Nature Scientific Data”:

Purchase the map, SWAT lookup table, and SWAT2012.mdb
Global Soil FAO-UNESCO