1. Soil Survey: Backing Up to Look Forward and Revise the Map Ron Taskey Professor Emeritus California Polytechnic State University and Natural Resources Conservation Service

2. THE MAPPER’S JOB: Recognize, record, interpret, and convey meaningful soil geographic patterns. CONCEPTUAL METHOD taxonomic units Create taxonomic units: Locate, describe, and classify a range of soils (point data). map units Create map units: Infer and delineate patterns of taxonomic units as revealed by spatial changes in one or more of the soil-forming factors.

3. Develop soil-landscape models that correlate point data (taxonomic units) with landscape features to create spatial patterns (map units).

4. Sounds good, but As much art as science. Relies on tacit knowledge. Learn and proceed by trial and error. Little written guidance. GAP Concept––––––GAP–––––––Practice

5. Map units: created from vague, unwritten criteria based on inferences from soil forming factors and anticipated land uses. Taxonomic units: based on elaborate, exacting, uniform criteria arranged in a strict written hierarchy (Soil Taxonomy).

6. Assigning priorities to soil forming factors. Maintaining consistent priorities among mappers. Maintaining consistency year to year. Maintaining consistency across landscapes. Dealing with problems of scale. Adapting future survey updates. Anticipating land uses and judging their longevity. Challenges in Creating Map Units

7. Problems Different pedologists–different approaches–different priorities–different decisions. Models rarely written. Few mappers record hypotheses, or explain rationale for map unit designs. Taxonomic unitsTaxonomic units: exacting, written criteria. Map units Map units: uncertain, unwritten criteria. Taxononomic units and map units are different concepts, but are named similarly. Unclear, uncertain, or misleading connections between soil taxonomic units and map units. Different scales require different approaches. Confusion and misconception among clients, trainees, and other professionals.

8. What’s the root of the problem? What can we do about it? Back up and reconsider map unit concept.

9. To create taxonomic units: Select sites Describe soils Classify soils-Soil Taxonomy Rational-deductive-analytical –certain outcome

10. To create map units: Infer taxonomic patterns revealed by spatial changes in one or more soil forming factors. Empirical-inductive-synthetic –uncertain outcome

11. New Principle, Definition, or Guidance Established Principle, Definition, or Guidance DeductionInduction Certain outcomeUncertain outcome

12. System for classifying soil-landscapes that is rational-deductive-analytical and structured as a natural hierarchy. i.e., a soil-landscape taxonomy to accompany soil taxonomy What’s Needed?

13. Soil-Landscape Taxonomy Land Type ComponentSubcomponentElementModifier Soil Taxonomy OrderSuborder Great Group SubgroupFamily Series “Soil-Landscape Series”

14. Map units and taxonomic units can be developed concurrently, nonetheless they are separate and distinct products. Soil-Landscape Taxonomy (natural landscape hierarchy) Soil Taxonomy (Keys to Taxonomy) Interpretations (empirical-inductive-predictive)

15. Easy to teach, easy to learn. Not only what was done, but also how it was done.