Identifying Horizons of Soil Profiles

Test your ability to identify horizons and soil types from Washington State.

Below are several soil profiles from different locations in Washington State. All colors given are for moist soil. Using the pictures and characteristics, identify the horizons in each profile. Can you identify the soil order?

Don't understand a term?  Use the glossary to obtain a definition. For help classifying the soil, see the Keys to Soil Taxonomy or Soil Basics for a simplified key.

Select a box below if you wish to try a soil profile different from Soil Profile No. 1

Profile 2

Profile 3

Profile 4

Profile 5
 

Soil Profile No. 1. Found in low elevation areas of southwestern Washington; deep, poorly drained soils formed in herbaceous and woody deposits in valley bottoms or glacial till plains. Slopes are 0 to 1 percent. Average annual precipitation is 100 cm and mean annual temperature is 10 degrees centigrade.

 

 Profile Description

  1. 0-28 cm; black (5YR2/1); sapric material, about 10% fibers, less than 1% rubbed fibers; granular structure; friable, nonsticky, nonplastic, many roots; pH=5.4; clear smooth boundary

  2. 28-43 cm; dark reddish brown (5YR2/2); hemic material, about 60% fibers, 25% rubbed fibers; platey structure; very hard, very friable, nonsticky and nonplastic; common roots; pH=5.1; clear smooth boundary

  3. 43-53 cm; black (5YR2/1); sapric material, about 5% fibers, less than 1% rubbed; massive; very friable, slightly sticky and slightly plastic; few roots; pH=4.8; clear wavy boundary

  4. 53-90 cm; very dark brown (7.5YR2/2); sapric material, about 45% fibers, 15% rubbed; massive; very friable, nonsticky, nonplastic; few roots; pH=6.0

  5. 90-150+ cm; dark brown (7.5YR3/4); hemic material, about 70% fibers, 35% rubbed; massive; very friable, nonsticky, nonplastic; few roots; pH=5.8

Choose the correct master and subordinate horizon designations for each horizon from the options below, then click on 'answer' to check your determination.

Horizon No. 1: A O Oa Oi
Horizon No. 2: Oa2 Oe Oa Ob
Horizon No. 3: Oab Oa2 Oe Oi
Horizon No. 4: Oe2 Oa3 Oe 2Oa
Horizon No. 5: Oe2 Oa3 Oe Oa3

Can you determine the Order, Suborder or Great Group of this soil?

Order:

Order and Suborder:

Order, Suborder and Great Group:

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Profile 2

Profile 3

Profile 4

Profile 5