Warm-up for Today Put your Erosion article summary in the Turn-In Bin. Clear your desk. All you need is your agenda and a pen/cil.

Soil Formation and Composition Section 7-2

Dirt Excrement Filthy or soiling substance Something worthless Synonyms: filth, dust, grime, muck

Soil The loose upper layer of the Earth’s crust in which plants can grow

We do NOT say “Dirt”, We say “SOIL” !!!

Where does soil come from? Weathered Rock + other stuff Soil

Bedrock The solid rock in Earth’s crust When exposed at the surface, it weathers into smaller and smaller pieces to become soil

Bedrock weathers to Rock Particles

What is the “other stuff?” Humus Air Water

Humus The organic part of soil Formed from decomposed organisms dark-colored Rich in nutrients

Loam Loam is the BEST kind of soil. Loam has a good balance of air and water, and holds LOTS of nutrients. Loam contains equal parts of Sand (drainage) Silt Clay (holds water)

O = litter A = topsoil B = subsoil C = parent material bedrock Soil Horizons O = litter A = topsoil B = subsoil C = parent material bedrock

Life Science RE:visited The Weatherers The Defecators The Decomposed The Decomposers The Aerators

What is the relationship between weathering and soil? Let’s Review! What is the relationship between weathering and soil?

What different materials make up soil? Let’s Review! What different materials make up soil?

What is the best kind of soil? Let’s Review! What is the best kind of soil?

How do plants and animals affect soil? Let’s Review! How do plants and animals affect soil?

Bedrock weathers to Rock Particles

` DEPOSITION

Material added to land Sediment stops moving (erosion) depostion Material added to land Sediment stops moving (erosion) Organic stuff deposited

Loess