Soil series occurring together in repeating Geographic pattern are grouped into

Soil series occurring together in repeating geographic patterns are grouped into Soil association. It is a group of closely associated soil profiles on one parent material and one soil zone.
The soil association developed the world's first organic standards in 1960.
A place name is assigned to each soil association. That place name is usually the name of a town near where the soil was first recognized and described by soil surveyors.