soils physical properties. composition of average soil

Soils

Physical Properties

Composition of Average SoilOrganic5%

Water25%

Mineral45%

Air25%

Air Water Mineral Organic

Factors Affecting Soil Formation

Climate

Living Organisms (plants and animals)

Parent Soil Material

Topography

Time

How To Determine Soil Texture If soil crumbles

easily, feels markedly gritty with a lack of smoothness

The soil is coarse textured and may be

Sandy loam or loamy sand

which depends on the sand content.

How To Determine Soil Texture

If no ribbon forms, and the soil feels smooth with slight or no grittiness,

The soil is medium textured and may be

Loam, Silt Loam, or Silt.

How To Determine Soil Texture

If you can form a ribbon from a ball of moistened soil,

the soil is fine textured and may be

Clay, Silty Clay, or Sandy Clay.

Determining soil TexturePick up soil sampleRub between thumb

and fingers feel whether it is

Sandy coarse-gritty feel

Loamy medium-silty, floury

Clay fine-sticky when wet

The Relative Sizes of Sand, Silt, and Clay Particles

Sizes of Particles

Name Size,Diameter in Millimeters

Very coarse sand 2-1Coarse sand 1.00-0.50

Medium Sand 0.50-0.25Fine sand 0.25-0.10

Very Fine Sand 0.10-0.05Silt 0.05-0.002

Clay Less than 0.002