SOIL 205 Soil Science

Lecture Hours: 3
Lab Hours: 3
Credits: 4

Explores soil ecosystems as a medium for plant and crop growth, the cycling of nutrients, supply and purification of water, and a habitat for diverse population of soil organisms. Also studies the relationship of human activities to the sustainability of soil ecosystems.

Student Learning Outcomes:

Discuss the various functions of soils in natural and managed ecosystems.
Explain the five primary soil forming factors and the four basic processes of soil formation
Describe the major characteristics, the general degree of weathering and soil development, and the worldwide distribution and uses of the 12 soil orders.
Understand the morphological, physical, and biological properties and processes of the soil.
Apply soil science concepts to plant production and to everyday experiences.
Critically evaluate the impact of human activities on soil and environmental quality.

Content Outline

Importance of Soil
- Functions of soil
  - Nutrient cycling
    - Recycling system for nutrients and organic wastes
  - Water Relations
    - System for water supply and purification
  - Biodiversity and habitat
    - Soil food web
  - Filtering and buffering
    - Filters to protect the quality of water, air, and other resources
  - Physical stability and support
    - Medium for plant growth
    - Anchoring support for human structures
Soil Formation
- Five primary soil forming factors
  - Parent material
  - Climate
  - Biotic activities
  - Topography
  - Length of time
- Four soil forming processes
  - Additions
  - Losses
  - Transformations
  - Translocations
Soil Taxonomy
- Soil classification
- 12 soil orders
  - Major diagnostic features
Soil Properties
- Soil components
- Soil profiles
  - Parent material
  - Soil horizons
- Physical propertiesTexture
  - Textural classes
    - Influence on soil properties
  - Structure
    - Development of structure
    - Structural types
- Chemical properties
  - pH
  - Cation exchange capacity
  - Common clay minerals
  - Soil organic matter
- Biological properties
  - Soil organisms
    - Bacteria
    - Fungi
    - Protozoa
    - Nematodes
    - Arthropods
    - Earthworms
    - Mycorrhizae
  - Important activities of soil organisms
  - Soil organic matter
Understanding Regional Soils
- Soil surveys
- Important soils in the Willamette Valley
Soil and Water Relationships
- Movement
  - Capillary flow
  - Gravitational flow
- Storage
- Irrigation needs
Soil Conservation and Improvement
- Soil quality
- Organic matter
- Cultural practices
- Erosion control
- Cover crops