R function that determines the USDA soil texture class of a soil based on percentage clay, silt and sand. Works with single values as well as with dataframes.
The code follows the texture definitions of the USDA. These can be found in the second sheet of the Soil Texture Calculator (MultiPointTriangle_v1.xlsm). This can be downloaded from the Natural resources Conservation Service of the U.S. Department of Agriculture (USDA): https://www.nrcs.usda.gov/resources/education-and-teaching-materials/soil-texture-calculator