texture, soil

The relative proportions of the various soil separates in a soil as described by the classes of soil texture shown in Figure1. The names of textural soil classes may be modified by adding suitable adjectives when coarse fragments are present in substantial amounts; for example, "Gibraltar stony sandy loam," or "Saint-Jovite silt loam, stony phase." For other modifications see coarse 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:

sand (sable)

Soil material that contains 85% or more sand; the percentage of silt plus 1.5 times the percentage of clay does not exceed 15. coarse sand (sable grossier) 25% or more very coarse and coarse sand, and less than 50% any other one grade of sand.

sand (sable)

25% or more very coarse, coarse, and medium sand, and less than 50% fine or very fine sand.

fine sand (sable fin)

50% or more fine sand or less than 25% very coarse, coarse, and medium sand and less than 50% very fine sand.

very fine sand (sable très fin)

50% or more very fine sand.

loamy sand (sable loameux)

Soil material that contains at the upper limit 85 to 90% sand, and the percentage of silt plus 1.5 times the percentage of clay is not less than 15, at the lower limit it contains not less than 70 to 85% sand, and the percentage of silt plus twice the percentage of clay does not exceed 30.

loamy coarse sand (sable grossier loameux)

25% or more very coarse and coarse sand and less than 50% any other one grade of sand.

loamy sand (sable loameux)

25% or more very coarse, coarse, and medium sand and less than 50% fine or very fine sand.

loamy fine sand (sable fin loameux)

50% or more fine sand or less than 25% very coarse, coarse, and medium sand and less than 50% very fine sand.

loamy very fine sand (sable très fin loameux)

0% or more very fine sand.

sandy loam (loam sableux)

Soil material that contains either 20% or less clay, with a percentage of silt plus twice the percentage of clay that exceeds 30, and 52% or more sand; or less than 7% clay, less than 50% silt, and between 43% and 52% sand.

coarse sandy loam (loam sableux grossier)

25% or more very coarse and coarse sand and less than 50% any other one grade of sand.

sandy loam (loam sableux)

30% or more very coarse, coarse, and medium sand, but less than 25% very coarse sand, and less than 30% very fine or fine sand.

fine sandy loam (loam sableux fin)

30% or more fine sand and less than 30% very fine sand or between 15 and 30% very coarse, coarse, and medium sand.

very fine sandy loam (loam sableux très fin)

30% or more very fine sand or more than 40% fine and very fine sand, at least half of which is very fine sand, and less than 15% very coarse, coarse, and medium sand.

loam (loam)

Soil material that contains 7 to 27% clay, 28 to 50% silt, and less than 52% sand.

silt loam (loam limoneux)

Soil material that contains 50% or more silt and 12 to 27% clay, or 50 to 80% silt and less than 12% clay.

silt (limon)

Soil material that contains 80% or more silt and less than 12% clay.

sandy clay loam (loam sablo-argileux)

Soil material that contains 20 to 35% clay, less than 28% silt, and 45% or more sand.

clay loam (loam argileux)

Soil material that contains 27 to 40% clay and 20 to 45% sand.

silty clay loam (loam limono-argileux)

Soil material that contains 27 to 40% clay and less than 20%sand.

sandy clay (argile sableuse)

Soil material that contains 35% or more clay and 45% or more sand.

silty clay (argile limoneuse)

Soil material that contains 40% or more clay and 40% or more silt.

clay (argile)

Soil material that contains 40% or more clay, less than 45% sand, and less than 40% silt.

heavy clay (argile lourde)

Soil material that contains more than 60% clay.

texture du sol

Figure 1

Soil textural classes. Percentages of clay and sand in the main textural classes of soils; the remainder of each class is silt. Source: Research Branch, 1976
Contact: Peter Schut