definition of soil textural triangle according to usda
The soil texture triangle is one of the tools that soil scientists use to visualize and understand the meaning of soil texture names. The textural triangle is a diagram which shows how each of these 12 textures is classified based on the percent of sand, silt, and clay in each. Note: these percentages are based on the USDA definition of sand and silt only. Follow these steps to determine the textural class name of your soil sample: 1) Determine the percent sand of your sample and find that number on the bottom of the triangle. Note that the numbers read from right to left, not left to right.