Crop models require quantitative descriptions of soil surface and profile properties. While many field experiments measure properties in the plow layer or expected zone of active root growth (often the top 30 cm of the profile), models require data for soil layers down to the depth of maximum root growth in order to account for drainage, leaching and possible deep penetration of roots under water deficits. Furthermore, properties such as bulk density and texture may not be considered in routine analyses.

Various soil databases may be consulted to obtain profile data. These include:

• WISE: Version 3.1 soil database with 9,613 profiles available http://www.isric.org/
• AfSIS soil database for Africa: 3,655 profiles from WISE Version 3.1 & 4,773 new Africa profiles, total 8,428
• For locations within the USA, the California Davis Soil Resource Lab has a series of web tools for accessing soil data held by USDA NRCS. These allow locating soils by soil series or a mapping tool. Instructions for using the web resources to obtain data required by DSSAT are found here.