UsingUsing SoilSoil TaxonomyTaxonomy toto IdentifyIdentify PotentialPotential HydricHydric SoilsSoils Soil Taxonomy

A basic system of soil classification for making and interpreting soil surveys Objective: To develop a hierarchical classification that reflects the relationships between different soils, and between soils and the factors responsible for their character. Soil Taxonomy

Soils are classified on the basis of: • Soil properties observed in the field (e.g., soil horizons, texture, color, pH) and • Soil properties inferred from the combined data of soil science and other disciplines (e.g., soil temperature and moisture regimes inferred from soil science and meteorology). Soil Taxonomy

Order Entisol 12 Orders

Sub Order Fluvent First sign of wetness

Great Group Ustic

Sub Group Mollic

Family Fine-loamy, mixed, frigid

Series Korchea Fine-loamy, mixed (calcareous), frigid, Mollic Ustifluvent (Korchea series, western ND) Soil Taxonomy

Nature of Number Differentiating Category of Taxa Characteristics

Order 12 Soil-forming processes as indicated by presence or absence of major diagnostic horizons Soil Orders

• Alfisols • Inceptisols • Andisols • Mollisols •Aridisols •Oxisols • Entisols • Spodosols •Gelisols • Ultisols • Histosols • Vertisols Dominant Soil Orders

Alfisols Andisols Aridisols Entisols Gelisols Gel/Inc (AK) Histosols Inceptisols Mollisols Oxisols Spodosols Ultisols Vertisols Taxonomic Names Soil Order Name Ends in: Alfisol -alf Andisol -and Aridisol -id Entisol -ent Gelisol -el Histosol -ist Inceptisol -ept Mollisol -oll Oxisol -ox Spodosol -od Ultisol -ult Vertisol -ert Entisol Suborders

• Aquents • Orthents (L. Aqua, Water) (Gr. Orthos, True) Wet Entisols The Typical Ones

•Fluvents • Psamments (L. Fluvius, River) (Gr. Psammos, Sand) Floodplain Soils Sandy Soils Examples of Entisol Great Groups

• Suborder • Great Groups Aquents Cryaquents - cold (Wet Entisols) Fluvaquents - floodplain Hydraquents - water Psammaquents - sand Epiaquents - perched Examples of Entisol Great Groups

• Suborder • Great Groups Fluvents Torrifluvents - torrid (Floodplain (hot and dry) soils) Tropofluvents - tropical (warm and humid) Udifluvents - humid (not dry in most years) Ustifluvents - semi-arid (between Udic-Aridic) Xerofluvents - semi-arid (Mediterranean climate) Examples of Entisol Great Groups

• Suborder • Great Groups Psamments Cryopsamments (Sandy Soils) Quartzipsamments - Quartz Torripsamments Udipsamments Ustipsamments Xeropsamments Interpreting Taxonomic Names

Subgroup - Great Group, Suborder, Order 4 3 2 1

Vertic Udifluvent • 4 - Vertic subgroup - invert, shrink-swell, high clay • 3 - Udi(c) great group - humid climate • 2 - Fluv(ic) suborder - floodplain • 1 - Ent(isol) order - little soil development Aquic Soil Moisture Regimes

• Typic subgroup of an aquic suborder: • Typic ____aqu____ –wettest • Aeric subgroup of an aquic suborder: • Aeric ____aqu____ – better aerated • Aquic subgroup: • Aquic ______–driest From Mausbach 1992 Examples of Subgroups

4 3 2 1 Typic Fluvaquents 4 1 2 Typical Entisols with aquic moisture regimes 3 that occur on floodplains.

1. Order 3. Great Group 2. Suborder 4. Subgroup Examples of Subgroups

4 3 2 1 Mollic Fluvaquents 1 2 Entisols with aquic moisture regimes that 3 occur on floodplains and have thick, 4 dark surface layers.

1. Order 3. Great Group 2. Suborder 4. Subgroup Examples of Subgroups 4 3 2 1 Aeric Fluvaquents 1 3 2 Entisols on floodplains with aquic moisture regimes that are not so wet. They are better 4 aerated in the “upper” part of the soil profile.

1. Order 3. Great Group 2. Suborder 4. Subgroup Soil Taxonomy

Nature of Number Differentiating Category of Taxa Characteristics

Series 15,000+ May have virtually the full range of properties that is permitted in a family, but in one or more properties the range is restricted, such as: - Kind and arrangement of horizons - Color -Texture - Structure Typic Medisaprists Typic Medisaprists Terric Haplosaprists Terric Haplosaprists Lithic Cryofolists Lithic Cryofolists Aquic Paleudalfs Aquic Paleudalfs Aquic Glossudalfs Aquic Glossudalfs Typic Aquisalids Typic Aquisalids Aquic Quartzipsamments Aquic Quartzipsamments Typic Humaquepts Typic Humaquepts Typic Argiaquolls Typic Argiaquolls Argiaquic Argialbolls Argiaquic Argialbolls Aeric Calciaquolls Aeric Calciaquolls Aeric Alaquods Aeric Alaquods Typic Umbraqults Typic Umbraqults Chromic Epiaquerts Chromic Epiaquerts