Appendix B. - Guide for Placing Soils in Capability Subclasses in California - Guides A and B

(Only soils in capability classes 2 through 8 are assigned to a subclass.)

Soil Properties

Guide A - For placing soils in land capability subclasses where wind velocities are low and/or soils are irrigated.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Guide B - For placing soils in land capability subclasses where high wind velocities occur and the soil is not irrigated.

Subclass by Slopes 1/

Subclass by Slopes 1/

0-2%

2-9%

9-15%

15+%

      

0-2%

2-9%

9-15%

15+%

      
1. Moderately slowly, moderate, moderately rapidly, rapidly and very rapidly permeable; moderately well, well, somewhat excessively and excessively drained soils (over 20" deep) with the following surface textures:

a. Fine and very fine textured

s

e

e

e

    

s

e

e

e

      

b. Moderately fine textured

s 2/,3/

e

e

e

    

e

e

e

e

     

c. Medium textured

s 2/,3/

e

e

e

   

e

e

e

e

     

d. Moderately coarse textured, with or without textural B

s 2/,3/

e

e

e

    

e

e

e

e

     

e. Coarse and very coarse textured with textural B

s

e

e

e

    

e

e

e

e

     

f. Coarse and very coarse textured with little or no textural B

s

s

s

e

      

e

e

e

e

     

2. Slowly and very slowly permeable soils (over 20" deep): 4/

a. Well and moderately well drained

b. Somewhat poorly drained

s

e

e

e

     

s

e

e

e

     

w

e

e

e

     

w

e

e

e

     

3. Wet, poorly and very poorly drained soils:

a. Moderately coarse to fine texturedsurface soils includes claypans and fragipans

b. Coarse textured soils with little or no textural B 5/

c. Deep organic soils 5/

      

w

w

w

e

     

w

w

w

e

     

w

w

w

e

     

w

w

w

e

     

w

w

w

e

     

w

w

w

e

     

4. Excessively, somewhat excessively, well and moderately well drained, shallow and very shallow soils:

a. 10 to 20" to bedrock

b. 0 to 10" to bedrock

15-50%

50+%

15-50%

50+%

s

e

e

e

e

s

e

e

e

e

s

s

s

s

e

s

s

s

s

e

5. Somewhat excessively, excessively, well and moderately well drained saline and sodic soils (moderate to severe salinity and sodicity):

s

e

e

15+%
e

     

s

e

e

15+%
e

     

6. Very and extremely cobbly; very and extremely gravelly; and very and extremely stony surface layers:

 s

s

s

15-30%
s

30+%
e

s

s

s

15-30%
s

30+%
e

7. Soils subject to damaging overflow:

 w

w

w

e

     

w

w

w

e

     

   TOP

1/ For soils in capability classes 2 through 8. Class 1 land excluded.

2/ These soils over 40" deep are generally class 1.

3/ Use "C" only for dryland if soil is class 1 irrigated.

4/ Permeability of the B horizon or control section.

5/ Including somewhat poorly drained soils.