All About Soil

All About Soil

Soil can basically be separated into 5 main parts:

1.Humus2.Clay3.Silt4.Sand5.Gravel

Humus: A dark, moist soil composed of bits of dead, rotting insects, animals, leaves, roots, sticks, and food.  Humus adds nutrients to the soil which plants need to grow and live.

Clay: A soil that holds water.  When wet, clay feels slippery and slimy.  It is made of particles that are smaller than 0.004 millimeters.

Silt: Soil that looks like fine grains or tiny pieces of rock.  Particles classified as silt measure from 0.004 millimeters to 0.006 millimeters.

Sand: Soil that is coarse and drains quickly.  Sand particles measure from about 0.006 millimeters to 2.00 millimeters.

Gravel: Visible rock particles, sometimes referred to as pebbles.

What is a Soil Profile?• A soil profile is

a view

of a cross section of soil.

Characteristics of the Soil Horizons

• 0 Horizon-located on surface, mostly O.M.

• A Horizon-Called Topsoil, good amounts of O.M. and minerals.

• B Horizon- Known as Subsoil, Less O.M.

• C Horizon- Mostly parent material, does little for plant growth.

What is soil texture

• It is the relative sizes of the different soil

particles.

The major Soil Texture Classes

• Sand-largest particle

• Silt-medium size particle

• Clay-smallest particle

Characteristics of aSandy Soil

Characteristics of a Silty Soil

Characteristics of a Clay Soil

Using the Soil Texture Triangle

What is Soil Structure?

• Sand, silt and clay particles combine with one anther to form cluster called aggregates.

• The way in which aggregates or clusters are arranged is referred to as soil structure.

Soil Structure Categories