Developing an Illustrated Guide to US Soil Taxonomy

Developing an Illustrated Guide to US Soil Taxonomy Janis Boettinger, Utah State University Craig Ditzler, NRCS-NSSC (retired) Kim Kerschen, KSU (MS student) Paul Mc. Daniel, University of Idaho Curtis Monger, New Mexico St. Univ. Phillip Owens, Purdue University Kenneth Scheffe, NRCS-NSSC Mark Stolt, University of Rhode Island Joe Chiaretti, NRCS-NSSC (retired) John Galbraith, Virginia Tech Cam Loerch, NRCS-NSSC (retired) Shawn Mc. Vey, NRCS-NSSC Toby O’Geen, Univ. California-Davis Mickey Ransom, KSU (Co-chair) Joey Shaw, Auburn University David Weindorf, Texas Tech University

Background p Soil Taxonomy (ST) conceived in 1950 s, with input from many systems, committees n n Seven drafts circulated through the 1960 s 1975: 1 st Ed. Soil Taxonomy published 1999: 2 nd Ed. Soil Taxonomy published (869 pp. ) Keys to Soil Taxonomy (a 372 pp. subset) n n n 12 updates since 1975 (latest is 2014) Spanish translation and e-book versions available Six level hierarchy, 5 in eliminatory key format n Order, suborder, great group, subgroup, family

Strengths 1. Every soil is allocated to a class through the family level. 2. Strongly enables soil survey production and interpretation. 3. Decisions can be made in the field, supported with surrogate information, and validated with lab data if needed. 4. The names of classes are descriptive, based on scientific terms, and include the top five levels. 5. Used in over 137 countries. 6. Great groups are basis for new Universal Soil Classification. 7. The system can be fixed if it is wrong, new soils can be added, and improvements suggested through a systematic process.

Weaknesses p Soil Taxonomy uses complex criteria n Based on quantitative limits n n n Complex wording – connectors n n n Chemical, physical variables Climate (moisture, temperature regimes) Depths, thickness Relative and absolute comparisons and or both of one of does not contain etc. Precise, but not simple to follow Many exceptions included for rare soils

Weaknesses Fine-loamy, mixed, superactive, thermic Aridic Paleustalf p An example of the first 5 levels, ranked lowest to highest! 5 4 3 2 1 p To an experienced American pedologist, this makes perfect sense – but college students, consultants, landowners, and the general public ….

Weaknesses q q *Many different authors, so the writing style is not consistent throughout, esp. between mineral and organic soils. *No key to epipedons or diagnostic horizons and characteristics, each must be checked. *Not enough pictures or simple descriptions of diagnostics in the Keys. Terms horizon and layer have multiple meanings but the terms are used interchangeably.

Solution – An Illustrated Guide p p NOT INTENDED TO REPLACED KEYS TO SOIL TAXONOMY! Target is 85% accuracy. Complimentary guide focused on concepts n Wider use of illustrations, horizon and profile photos, maps, and flow diagrams

Progress and Contents p p p Part 1: How to use this Version of the Keys n Introduction to the Illustrated Guide… n General Steps to Follow When Classifying a Soil n Soil Moisture and Temperature Regimes Part 2: Diagnostic Horizons and Features Part 3: Keys - Orders, Suborders, Great Groups

Example

Soil Temperature Regimes

General Layout - Epipedons

Example – Soil Order Keys

Example: Alfisols Soil Order

Illustrated Guide p Target Audiences: n n n n College students studying soils for the first time Consultants Natural resource managers Agronomists Foresters Engineers Rangeland specialists

Illustrated Guide p Different focus n n Keys to Soil Taxonomy: Quantitative limits on all categories through the great group (3 rd) level Illustrated Guide: Concept statements through the 4 th level Simpler terms, avoiding jargon More visual teaching style, not just technical guide

Illustrated Guide p Other differences n n n More illustrations Definitions of master horizons, subordinates, diagnostic subsurface horizons, and epipedons Extensive hyperlinks to definitions or additional data sources

Questions?