- Know and understand the five soil-forming factors and how they influence the formation of local soils.
- In the field, determine the soil properties of texture, structure, color, pH, slope %, slope position, water runoff class, and water permeability.
- Learn the major properties of cambic, calcic, and argillic diagnostic horizons.
GOAL: To perform a soil morphological description in the field
- 9.5: Soil Classification
- Soils in the United States are classified according to the USDA Soil Taxonomy. Soil Taxonomy includes the system of soil classification published by the Soil Survey staff of the U.S. Department of Agriculture’s Natural Resource Conservation Service (NRCS), formerly the Soil Conservation Service (SCS). This system provides a comprehensive natural classification of soils based upon measurable and observable soil morphological properties.
- 9.7: Slope and Runoff
- The amount of soil erosion is directly related to the amount of surface water runoff, which depends on the water infiltration rate and the % slope. The steeper the slope and the less rapid the water infiltration rate, the more rapid the water runoff rate for a given soil. Soils having granular structure and high porosity have slower water runoff rates than do soils with massive structure and low porosity.
- 9.8: Soil Permeability
- Soil permeability is the quality of a soil enabling it to transmit air or water through the soil pores. Texture, structure, cracking, and the amount of organic matter influence the permeability.
- Field Book for Describing and Sampling soils (aka the RED BOOK) https://www.nrcs.usda.gov/Internet/F...2p2_052523.pdf
- Soil data explorer available from UC Davis https://casoilresource.lawr.ucdavis.edu/gmap/