1. Soil Taxonomy- Properties of Soil
Plant & Soil Science

2. Property #1: Soil has Horizons (layers)

3. Property #2: Soil has Color…

4. Property #3: pH Levels

5. Soil Property #4 - Organic Content
Desert soils have low organic content.
Grasslands have high organic content.
The exact type of vegetation is also important because it also affects pH.
Pine needles add acid to the soil.
Grasses conserve calcium and magnesium (bases).
Most crops like a neutral pH.

10. Order

11. Soil Taxonomy- 12 Soil Orders
Soils are classified into into six categories based on diagnostic characteristics
The last (largest) category will place the soils into one of the 12 Soil Orders.

12. Soil Taxonomy Fine-loamy mixed, superactive, mesic Aquic Argiudolls
(This is the name of a specific soil in Soil Taxonomy)
Orders (12)
Suborders (54)
Great Groups (211)
Subgroups (1,100+)
Family (7,000+)
Series (a lot!)
This is the name of one
Of the 12 large categories
Mollisol - oll
Oder root of order

13. Orders
Fine-loamy mixed, superactive, mesic Aquic Argiudolls
Highest and most general of the soil classification system (similar to the phylum in plant taxonomy)
Based on conditions under which the soil developed
Order
oll = Mollisols

14. Suborders
Fine-loamy mixed, superactive, mesic Aquic Argiudolls
Sub
Order
Grouped by similarities in soil formation such as wetter/dryer soil, colder/warmer soil, etc.
Ud = Udic Moisture

15. Great Groups (not required to know)
Fine-loamy mixed, superactive, mesic Aquic Argiudolls
Sub
Order
Order
Great
Group
Based on differences between soil horizons
Argi = Clay
accumulation

16. Sub Groups (not required to know)
Fine-loamy mixed, superactive, mesic Aquic Argiudolls
Sub
Order
Sub
Group
Describes a profile characteristic, wetness, sand, etc.
Order
Great
Group
Aquic = wet soil

17. Family (not required to know)
Fine-loamy, mixed, superactive, mesic Aquic Argiudolls
Sub
Order
Sub
Group
Family
Texture, clay minerals, CEC, temp,
Order
Great
Group
Based on soil properties that affect management and root penetration, such as texture, temperature, and depth

18. Series (not required to know)
Fine-loamy mixed, superactive, mesic Aquic Argiudolls
Sub
Order
Sub
Group
Family
Order
Great
Group
Named from the town or landscape feature near where the soil was first recognized (Eleva= Eleva, WI or Gale for Galesville, WI .)

19. Soil Orders – Upper Midwest

20. 12 Soil Orders - Each Order has a diagnostic epipedon and subsurface horizons – which could be “none”. WEB SITE for soil orders =
Entisol
Inceptisol
Andisols
Spodosols
Mollisols
Alfisols
Ultisols
Oxisols
Aridisols
Vertisols
Histosols
Gelisols

21. The 12 Soil Orders

22. Orders with unique parent materials:

23. Andisols (and)
Volcanic ash soils.

24. Histosols (ist)
Organic soils.

25. Vertisols (ert)
High shrink/swell clay soils.

26. Orders formed in unique
environments.

27. Aridisols (id)
Arid climates.
CaCO3 accumulation in subsoil.

28. Gelisols (el)
Colder climates.
Permafrost layer within 2 m of surface.

29. Oxisols (ox)
Tropics and subtropics.
Intensely weathered.

30. Orders by age.

31. Entisols (ent)
‘Baby’ soil.
Little to no morphological development.

32. Inceptisols (ept) ‘Toddler’ soils.
Weakly developed sub-surface horizons.

33. Ultisols (ult) Older soils. “Ultimately weathered”. Strongly leached.
Sub-surface clay accumulation.
< 35% base sat. in sub-soil.

34. Orders developed under unique
vegetative ecosystems.

35. Alfisols (alf) Forest soils.
Usually an A-E-B type horizon development.
The A horizon is usually less than 25 cm.

36. Mollisols (oll) Grasslands soil. Thick, dark A horizon.
High % base saturation.

37. Spodosols (od) Acid forest soils. Usually sandy.
Thick, bright white E horizon.
Sub-surface layer of accumulated metal-humus complex (Bhs and Bs horizons).

38. Summary:
3 orders with unique parent materials (Andisols, Histisols, Vertisols).
3 orders with unique environments (Aridisols, Gelisols, Oxisols).
3 orders by age of development (Entisols, Inceptisols, Ultisols).
3 orders by unique vegetative influence (Alfisols, Mollisols, Spodosols).

39. Resources http://soils.usda.gov/technical/soil_orders/