1. Table of Contents Title: 7.3 Soil Texture, Fertility and Color
Page #: 62
Date: 1/29/2013

2. Objectives
Students will be able to differentiate among the factors of soil formation.

3. Words of the Day Hue: Color Value: Lightness or darkness
Chroma: Intensity

4. Soil Texture Particles of soil are classified by their size.
There are 3 classifications:
1) Clay (smallest particles)
2) Silt (medium particles)
3) Sand (largest particles)
Particle size effects soil’s capacity to retain moisture and to support plant growth.

5. USDA Soil
Classification

6. Soil Fertility
Fertility: A measure of how well a soil can support growth.
Factors of fertility:
Topography
Availability of minerals and nutrients
Microorganisms present
Amount and availability of precipitation
Commercial fertilizers put nitrates, potassium and phosphorous into soils.

8. Soil Color
Determined by the minerals, organic matter and moisture in each soil horizon.
O and A horizons are dark in color = Rich in Humus
Red and yellow soils = oxidation of iron minerals (rust)
Yellow soils = environmental problems, poor drainage
Gray / blue soils = poor drainage, little oxygen
Scientists describe soil color using the Munsell System of Color Notation.
3 Parts:
Hue (color)
Value (lightness, darkness)
Chroma (intensity)

9. The Munsell System of Color Notation

10. Using the Munsell System of Color Notation