Unified Soil Classification System group symbol. For example, GW-GM corresponds to "well-graded gravel "with silt"." If the soil has more than 15% by weight retained on a #4 sieve (R > 15%), there is a significant amount of gravel, and the suffix "with gravel" may be added to the group name, but the group symbol does not change. For example, SP-SM could refer to "poorly graded SAND with silt" or "poorly graded SAND with silt and gravel." Unified Soil Classification System The Unified Soil Classification System (USCS) is a soil classification system used in engineering and geology to describe the texture and grain size
Natchez silt loam pasture and row crops are grown and the soil is very productive when good management is applied. A typical Natchez soil profile consists of a 3 inch top soil of dark grayish brown silt loam and to 8 inches, a subsurface of brown silt loam, a yellowish brown and dark yellowish brown silt loam subsoil to 36 inches and a substratum that is yellowish brown, and dark yellowish brown silt loam down to 80 inches. Classified as coarse-silty, mixed, superactive, thermic typic eutrudepts: Natchez soils are in the Inceptisols soil order. Inceptisols soils have developed in relatively young material that