Science Starter 4/10True or false

Ice wedging only occurs in winter. The layers of soil are called horizons. The darker the soil the less organic matter it in it. Humus is a man made, non-organic matter that

is in soil. Soil profiles all over the world are the same.

Answers FALSE TRUE FALSE FALSE FALSE

Foldable wordsPicture, Definition, and example

Chemical weathering Mechanical weathering Humus Soil Horizons Texture of soil Pore Space of soil

Stop Treating Soil Like Dirt!Let’s explore this very important part of

your life.

What is Soil?Soil is a mixture of four materials:• Weathered rock• Organic matter (remains of plants and animals)

• Water• Air

Water (~25%)

Air (~25%)Rocks

(Minerals)(~45%)

Organic Matter (leaves, plant roots, etc)

(~5%)

Soil Components

Q: What’s the difference between soil and dirt?

A: Location, location, location!

• Dirt is what you find on the floor.• Soil is what you find in the ground (the top layer of the Earth’s surface).

http://www.mii.org

Why the color?http://www.msstate.edu http://www.cs.cmu.edu

Hematite: red Goethite: yellowish brown

Ferrihydrite:reddish brown

http://www.beg.utexas.edu

Calcite: off white

http://www.pitt.edu

Quartz:white

Organic matter:black

http://www.organicgardeninfo.com

A horizon: organic coatings

B horizon: Iron coatings

C horizon: little coating

Soil Color by Horizon

http://nesoil.com

Soil Color Variation

Soil Color – Variation by GeographyRed soils: Southeast US

Soil Color – Variation by Geography

Brown/black soils: Midwest

http://www.scienceclarified.com

Soil Color – Variation by Geography

White (gypsum) sands: New Mexico

Soil Size

http://school.discoveryeducation.com

Fine Texture - Clay

https://www.soils.org/lessons

Course Texture - Sand

https://www.soils.org/lessons

Thien, 1979

Fun Fact: There are over 20,000 different soil types of soil recognized in the

US alone!!!!

The kind of soil that forms in an area depends on MANY factors, including: The kind of rock in the area The area’s climate The landforms in the area (mountains) Time The animals and other organisms in the area

The kind of soil determines what you can growin it, what you can build on it, and whathappens to therainwater that falls on it.

Property Sand Top-soil ClayWater holding Low Med-high HighNutrient supplying Poor Med-high High

Does the Type of Soil Matter?

Yes!! Some soils are stronger for buildings, some hold nutrients better.

Without soil, there would be no jeans. That's right! Jeans are made of cotton denim

stitched together with cotton thread. Their blue color comes from indigo dye. Cotton and indigo come

from plants that need soil to grow.