soil texture

What is soil texture?

soil texture meaning in Soil Science terminology / glossary / dictionary is:
The relative proportions of the various soil separates in a soil as described by the classes of soil texture shown in Fig. 1. The textural classes may be modified by the addition of suitable adjectives when rock fragments are present in substantial amounts; for example, “stony silt loam.” (For other modifiers see also rock fragments.) The sand, loamy sand, and sandy loam are further subdivided on the basis of the proportions of the various sand separates present. The limits of the various classes and subclasses are as follows:

  • clay – Soil material that contains 40% or more clay, <45% sand, and <40% silt.
  • clay loam – Soil material that contains 27 to 40% clay and 20 to 45% sand.
  • loam – Soil material that contains 7 to 27% clay, 28 to 50% silt, and <52% sand.
  • loamy sand – Soil material that contains between 70 and 91% sand and the percentage of silt plus 1.5 times the percentage of clay is 15 or more; and the percentage of silt plus twice the percentage of clay is less than 30.
    • loamy coarse sand – Soil material that contains 25% or more very coarse and coarse sand, and <50% any other one grade of sand.
    • loamy sand – Soil material that contains 25% or more very coarse, coarse, and medium sand, <25% very coarse and coarse sand, and <50% fine or very fine sand.
    • loamy fine sand – Soil material that contains 50% or more fine sand (or) <25% very coarse, coarse, and medium sand and <50% very fine sand.
    • loamy very fine sand – Soil material that contains 50% or more very fine sand.
  • sand – Soil material that contains 85% or more of sand; percentage of silt, plus 1.5 times the percentage of clay, shall not exceed 15.
    • coarse sand – Soil material that contains 25% or more very coarse and coarse sand, and <50% any other one grade of sand.
    • sand – Soil material that contains 25% or more very coarse, coarse, and medium sand, <25% very coarse and coarse sand, and <50% fine or very fine sand.
    • fine sand – Soil material that contains 50% or more fine sand (or) <25% very coarse, coarse, and medium sand and <50% very fine sand.
    • very fine sand – Soil material that contains 50% or more very fine sand.
  • sandy clay – Soil material that contains 35% or more clay and 45% or more sand.
  • sandy clay loam – Soil material that contains 20 to 35% clay, <28% silt, and >45% sand.
  • sandy loam – Soil material that contains 7 to 20% clay, more than 52% sand, and the percentage of silt plus twice the percentage of clay is 30 or more; or less than 7% clay, less than 50% silt, and more than 43% sand.
    • coarse sandy 1oam – Soil material that contains 25% or more very coarse and coarse sand and <50% any other one grade of sand.
    • sandy loam – Soil material that contains 30% or more very coarse, coarse, and medium sand, but <25% very coarse and coarse sand, and <30% very fine or fine sand, or <15% very coarse, coarse, and medium sand and <30% either fine sand or very fine sand and 40% or less fine plus very fine sand.
    • fine sandy loam – Soil material that contains 30% or more fine sand and <30% very fine sand (or) between 15 and 30% very coarse, coarse, and medium sand, or >40% fine and very fine sand, at least half of which is fine sand, and <15% very coarse, coarse, and medium sand.
    • very fine sandy loam – Soil material that contains 30% or more very fine sand and <15% very coarse, coarse, and medium sand (or) >40% fine and very fine sand, more than half of which is very fine sand and <15% very coarse, coarse, and medium sand.
  • silt – Soil material that contains 80% or more silt and <12% clay.
  • silty clay – Soil material that contains 40% or more clay and 40% or more silt.
  • silty clay loam – Soil material that contains 27 to 40% clay and <20% sand.
  • silt loam – Soil material that contains 50% or more silt and 12 to 27% clay (or) 50 to 80% silt and <12% clay.

 

reference: Soil Science Society of America