Soil Formation and Classification

The National Cooperative Soil Survey identifies and maps over 20,000 different kinds of soil in the United States. Most soils are given a name, which generally comes from the locale where the soil was first mapped. Named soils are referred to as soil series.

Soil survey reports include the soil survey maps and the names and descriptions of the soils in a report area. These soil survey reports are published by the National Cooperative Soil Survey and are available to everyone.

Soils are named and classified on the basis of physical and chemical properties in their horizons (layers). "Soil Taxonomy" uses color, texture, structure, and other properties of the surface two meters deep to key the soil into a classification system to help people use soil information. This system also provides a common language for scientists.

Soils and their horizons differ from one another, depending on how and when they formed. Soil scientists use five soil factors to explain how soils form and to help them predict where different soils may occur. The scientists also allow for additions and removal of soil material and for activities and changes within the soil that continue each day.

The soil forming factors are parent material, climate, topography, biological factors, and time.

Soil Keys to Taxonomy Field Book- Version 2
Keys to Taxonomy- 11th Edition
Glossary Of Soil Science Terms

Other Links

Soil Formation and Classification
Soil Forming Factors- 5 Factors
Soil Temperature Regimes
Soil Moisture Regimes
Soils Defined

Hydric Soils and Wetland Soils Training

other Training Opportunities in Wetland and Soil Science

Online Wetland and Conservation Training Courses

other Resources- http://soils.usda.gov/education/facts/soil.html