Updates for Universal Soil Classification and Proposal Process for Soil Taxonomy.

Updates for Universal Soil Classification and Proposal Process for Soil Taxonomy

Jonathan Hempel, USDA-NRCS, Lincoln, NE, Erika Micheli,  Szent Istvan University, Godollo, Hungary, Phillip Owens, 915 W. State St., Purdue University, West Lafayette, IN Craig Ditzler, USDA-NRCS, retired, Lincoln, NE, Ken Scheffe, USDA-NRCS, Lincoln, NE

 

The International Union of Soil Science Universal Soil Classification Working Group began engagement in early 2011 and built a core team that held their first workshop in May of 2011.  From the discussion at this meeting the core team has put together a framework of task groups, and priorities for moving forward with the effort to provide harmonized criteria for describing, sampling, analyzing and classifying soil, along with the work needed to understand gaps in existing soil classification systems. The framework is built into three distinct categories:

• Soil classification issues.
• Diagnostic and soil profile information harmonization.
• Important information relating to soil classification.

Each of these categories has specific task groups that have a designated chair, team members and a goal for what the group is to achieve.

As the Working Group has deliberated options for the future of a universal soil classification system, a centroid-based approach is being considered. This would involve analyzing databases to make allocations of soil properties into logical clouds designed to recognize “Great Soil Groups.” The Great Soil Groups will be equivalent to the great group level from U.S. Soil Taxonomy, along with similar levels in the World Reference Base, Australian Soil Classification, and other defined soil classification systems. The Great Soil Groups will have taxa developed that will document more and less detail. Lower taxa in the system will potentially recognize anthropogenic features, family criteria, climate and other important use and management characteristics. Higher taxa in the system will be developed for meso- and macroscale applications. As more data are added to the system, taxonomic distance calculations can be used to determine if new categories are needed based on tolerances that are set. This system can then be more scalable based on the objective analyses of the data that are collected and entered into the system.

While the USCS is being envisioned and developed, existing soil classification systems used internationally will continue to advance and be supported.  Toward this end, the Universal Soil Classification Working Group has proposed that Soil Taxonomy be recognized by the International Union of Soil Sciences as an approved system of soil classification.  To cultivate Soil Taxonomy as a system of international soil classification, changes are being instituted to the process for how proposals and updates are made to the system.  Two new committees are being formed to facilitate this.  The International Committee on Taxonomy (ICOMTAX) will consist of key international partners that will provide guidance on how recommendations for proposals from the international community would best be incorporated into Soil Taxonomy.  For proposals and changes that affect the national (US) soil classification issues, a committee will be established and a new process developed that will provide transparency and documentation for all proposals with recommendations made by consensus for approval by leadership.