USDA Soil Texturing Field Flow Chart

This single-sided, plastic-coated guide is designed to assist you in soil texturing procedures and in assigning a Texture Class using the USDA texture triangle. The flow chart features step-by-step procedures (adapted from Foth et al., 1992) for estimating the contents of sand, silt, and clay. Use this guide to quickly classify USDA soil textures in the field, achieve consistent results in soil texturing outcomes, identify subclass and textural class modifiers, differentiate between classification systems, and access detailed instructional reference pages.
The flow chart employs standard ribboning procedures to estimate the fine-grained fraction of soil, which is then placed within the texture triangle to determine the Texture Class. The guide also provides instructions for identifying the Subclass and assigning Textural Class Modifiers for rock fragments larger than 2 mm.