Soil = The relatively thin surface layer of the Earth’s crust consisting of mineral and organic matter.

The Rock Cycle

Soil is formed from ______ (bedrock) that’s slowly broken down through ______.

The 5 Soil-Forming Factors: Describe Soil Soil Composition:

Mineral Matter

AirWater

Organic Matter

  • POROSITY =
  • Pore spaces occupy ~50% of a soil’s volume
  • Soil Air contains the same gases as atmospheric air, but in different proportions.
  • Leaching
  • Illuviation

Soil Horizon = Distinctive layer of soil

Soil Profile = Vertical section of soil from surface to parent material, showing the soil horizons present.

Soil Organisms (bacteria, fungi, algae, microscopic worms, protozoa, plant roots, insects, earthworms, moles, snakes, groundhogs, etc.)

-Provide ecosystem services

-Earthworms & Ants -Mycorrhizae

PHYSICAL SOIL PROPERTIES:

  • Texture

Property / Sand / Silt / Clay
Water holding
Aeration
Nutrient supplying
Pollutant Filtering
  • Porosity & Permeability
  • Ionic Charge

-Clay particles have a ______charge

What happens to…

-positively charged mineral ions?

-negatively charged mineral ions?

  • Why would 100% sand be undesirable for plants?
  • Why would 100% clay be undesirable for plants?
  • A soil with a lot of ______would have good drainage, but poor nutrient-holding characteristics.
  • A soil with a lot of ______would have poor drainage, but good nutrient-holding characteristics.
  • A soil with a lot of ______would have low porosity.
  • A soil with a lot of ______would have high permeability.

CHEMICAL SOIL PROPERTY: Acidity!

  • Most soil pH is ______. Plants are happiest at ______.
  • How are plants affected by soil pH?

Why is soil important?

SOIL POLLUTION (Ch.21 R&B)

Soil Pollution= any physical or chemical change in soil that adversely affects the health of plants and other organisms living in and on it.

Many Soil Pollutants…

What can help solve the problem of soil pollution? ______

Salinization of Irrigated Soil

Effects of Salinized Soil on Plants

Soil Remediation

-Until recently, the only way to remove soil contaminants was to…

-Why is this a BAD idea???

Soil Remediation Techniques

Technique / What is it? How does it work? / Advantages / Disadvantages
Dilution
Vapor Extraction
Bioremediation
Phytoremediation

Activities that threaten soilPreventing Soil Erosion