(default; detailed soil map) or "STATSGO" (general soil map).
+
+
extract
Logical. Extract ZIP files to exdir? Default: TRUE
@@ -118,6 +123,7 @@ Value
Details
To specify the Soil Survey Areas you would like to obtain data you use a WHERE clause for query of sacatalog table such as areasymbol = 'CA067', "areasymbol IN ('CA628', 'CA067')" or areasymbol LIKE 'CT%'.
+When db="STATSGO" the WHERE argument is not supported. Allowed areasymbols include "US" and two-letter state codes e.g. "WY" for the Wyoming general soils map.
Pipe-delimited TXT files are found in /tabular/ folder extracted from a SSURGO ZIP. The files are named for tables in the SSURGO schema. There is no header / the files do not have column names. See the Soil Data Access Tables and Columns Report: https://sdmdataaccess.nrcs.usda.gov/documents/TablesAndColumnsReport.pdf for details on tables, column names and metadata including the default sequence of columns used in TXT files. The function returns a try-error if the WHERE/areasymbols arguments result in
Several ESRI shapefiles are found in the /spatial/ folder extracted from a SSURGO ZIP. These have prefix soilmu_ (mapunit), soilsa_ (survey area), soilsf_ (special features). There will also be a TXT file with prefix soilsf_ describing any special features. Shapefile names then have an a_ (polygon), l_ (line), p_ (point) followed by the soil survey area symbol.