Modern day soil taxonomy is based on the 7th Approximation- an early system of soil classification introduced to the soil community by scientists in 1960 in Madison!

An important resource for any soil judger or scientist. Soil is classified according to a dichotomous taxonomic key. In soil judging, student's classifications are based on this Key.

A simplified, beginner-friendly version of Keys to Soil Taxonomy. Perfect for students and those on the hunt for beautiful soil photos.

The Army Corps of Engineers is responsible for wetland classification and regulation. Hydric indicators are used by soil judgers to identify wetland soils.