What do all these tables contain?

There are twenty-two data tables that are part of a SSURGO soils data set.

Five of them contain information about the map units as a whole; ten of them contain data about the components; one contains horizon data; and there are six other tables that contain less-often used information that still needs to be looked up occasionally. Below you will see a diagram of the table relationships and then a brief text description of the tables.

Data Tables

The three main tables are mapunit, comp and layer. Mapunit stores information that applies to all components of a soil map unit, comp stores soil component information, and layer stores characteristics of soil layers for soil components.

There are four other tables that are mostly about mapping units. Inclusn stores the name of soils included in the soil map units, helclass stores the highly erodible land classification for wind and water assigned to the soil map units, muyld stores crop yield information for the soil map unit, and mucoacre stores the number of acres for the map unit within a county.

Nine more tables contain component level data. Wlhabit stores wildlife habitat information, woodmgt stores woodland management information, interp stores soil interpretation ratings (both limitation and suitability), compyld stores crop yield information, rsprod stores range site productivity information, woodland stores information on common indicator trees, windbrk stores information on recommended windbreak plants, plantcom stores plant symbols and percent of plant composition, and forest stores information for plant cover as forest understory.

Additionally, there are two tables that store information about the entire soil survey area. Ssacoac stores the acreage for the county within the boundary of the soil survey area and ssarea stores information that will apply to an entire soil survey area.

Last there are four tables that contain specialized information. Yldunits stores crop names and the units used to measure crop yield, rangenm stores the range site names, plantnm stores the common and scientific names for plants listed in the data base, and taxclass stores the taxonomic classification for soil components.

More information about the tables and the specific data elements in them can be found in the SSURGO Data Use Information booklet.