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Key Point 1—Physical Properties of Soil and Soil Formation

National Science Standards Correlation

Learning Objectives:
1. Understand the importance of soils and appreciate the relatively small amount of usable soil that exists on Earth.
2. Know the five soil forming factors, and understand how they influence soil properties.
3. Understand the origin and types of soil parent materials.
4. Understand basic soil forming processes: additions, losses, translocations, and transformations.
5. Recognize and understand features of Soil Profiles, and be able to use this information to determine basic soil properties and limitations.
6. Identify and describe soil characteristics (texture, structure, and color- using Munsell color charts).

Suggested Activities:
1. Generate a list of reasons why soils and the study of soil science is important to sustaining life on Earth, and explore how much soil available on Earth is for human use.
2. Describe the five factors of soil formation and be able to explain how each factor affects the soil profile.
3. Conduct a field analysis by digging or using an auger to examine a soil pit. Determine soil characteristics and properties, by describing soil horizons and recording data.
4. Use soil profile information to compare soil samples from agriculture cropland, wetland, forest and an urban area, and explain why there are differences in water table, permeability, runoff, infiltration and water holding capacity.
5. Estimate percent sand, silt, and clay for soil samples collected and determine texture class using the texture triangle. Explain how texture is important in soil fertility and soil management.


1. Why Soil is Important
2. How Much Soil is there?
3. From the Surface Down
4. Soil Formation and Classification
5. Sustain our Soils and Society 
6. Guide to Texture by Feel
7. Soil Field Analysis
8. Description of Soils: Soil Surveys, Chapter 3
9. State Soils: NRCS
10. Soil Landscapes of Canada



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