SOIL TEXTURE

'Soil texture' is a soil property used to describe the relative proportion of different grain sizes of mineral particles in a soil. Particles are grouped according to their size into what are called 'soil separates' (clay, silt, and sand). The soil texture class (eg. sand, clay loam, etc) corresponds to a particular range of separate fractions, and is diagramatically represented by the soil texture triangle. ''Coarse'' textured soils contain a large proportion of sand, ''medium'' textures are dominated by silt, and ''fine'' textures by clay.

Contents

Soil separate

Major texture classes

References

Soil separate

A 'soil separate' is a specific range of particle sizes. The larger sizes are described as ''coarse'', intermediate as ''medium'', and the smaller as ''fine''. (Different methods of soil texture classification define the separates slightly differently.)

''Name of soil separate''	''Diameter limits (mm) (USDA classification)''
Clay	less than 0.002
Silt	0.002 - 0.05
Very fine sand	0.05 - 0.10
Fine sand	0.10 - 0.25
Medium sand	0.25 - 0.50
Coarse sand	0.50 - 1.00
Very coarse sand	1.00 - 2.00

Major texture classes

There are 12 major texture classes:

★ Sand

★ Silt

★ Clay

★ Loam

★ Loamy sand

★ Sandy loam

★ Sandy clay loam

★ Sandy clay

★ Silt loam

★ Clay loam

★ Silty clay loam

★ Silty clay

References

★ Soil Texture, by R. B. Brown, University of Florida, Institute of Food and Agricultural Sciences.