Unit 647: Soil Science and Management

1. Soil Formation

1.1 Processes of Soil Formation

• Weathering of rocks: physical, chemical, and biological weathering
• Decomposition of organic matter
• Role of living organisms (plants, microbes, animals) in soil development

1.2 Soil Horizons and Profile Development

• Description of soil horizons (O, A, E, B, C, R)
• Factors influencing soil formation (parent material, climate, organisms, topography, time)

2. Soil Properties

2.1 Physical Properties

• Soil texture: sand, silt, clay proportions
• Soil structure: aggregates, porosity
• Soil color and its significance

2.2 Chemical Properties

• Soil pH and its impact on nutrient availability
• Nutrient content: macro- and micronutrients
• Cation exchange capacity (CEC)

2.3 Biological Properties

• Soil organic matter
• Microbial biomass and activity
• Soil fauna and their ecological roles

3. Soil Classification

3.1 Overview of Soil Classification Systems

• USDA Soil Taxonomy
• World Reference Base for Soil Resources (WRB)

3.2 Classification Criteria

• Soil texture and mineral composition
• Horizon arrangement and profile characteristics
• Diagnostic horizons and properties

4. Soil Water Relations

4.1 Water Movement in Soil

• Infiltration, percolation, and drainage
• Soil water retention and movement mechanisms

4.2 Soil Water Availability

• Field capacity
• Wilting point
• Available water content

5. Soil Fertility

5.1 Nutrient Cycling

• Mineralization and immobilization
• Role of organic matter

5.2 Factors Influencing Fertility

• Soil amendments
• Soil pH adjustments

5.3 Sustainable Agriculture Practices

• Crop rotation
• Organic amendments

6. Soil Erosion and Conservation

6.1 Causes and Impacts of Soil Erosion

• Water and wind erosion processes
• Consequences for soil structure and fertility

6.2 Soil Conservation Techniques

• Contour plowing
• Terracing
• Cover cropping
• No-till farming

7. Soil Microbiology

7.1 Microbial Communities in Soil

• Bacteria, fungi, archaea, and other microorganisms

7.2 Roles in Soil Processes

• Nutrient cycling
• Decomposition
• Soil health maintenance

8. Soil Testing and Analysis

8.1 Soil Sampling Techniques

• Sampling design and methods

8.2 Laboratory Analysis

• Measuring soil pH, nutrient levels, organic matter

8.3 Interpretation of Results

• Recommendations for soil management

9. Soil Amendments and Fertilizers

9.1 Types of Soil Amendments

• Compost, manure, lime, gypsum

9.2 Fertilizers

• Organic vs inorganic fertilizers
• Application methods and timing

9.3 Benefits and Environmental Considerations

• Improving fertility and productivity
• Minimizing negative environmental impacts