Land Judging in Oklahoma

James H. Stiegler, Extension Soils Specialist
Department of Plant and Soil Sciences

Table 2. Moderately Coarse, Medium, Moderately Fine, and Fine Textured Soils --- Deep and Moderately Deep

Slope Erosion Perm-
eability		 Surface
Runoff		 Capability
Class		 Factors
that keep
land out
of Class I		 Vege-
tative
Treatment		 Possible
Mechanical
Treatment
use one
or more
N.L. N V.S. S II 5 2,5,6 14,20
N.L. N V.S. V.S. III 5,6 3,5,6 14,18,20
G.S. N V.S. M III 3,5 3,5,6 14,15,16
 
G.S. M V.S. M IV 3,4,5 4,5,6 14,15,16
G.S. Sev. & V.S. M VI 3,4,5 7,8,9,10 14,19,20
- V. Sev. - - - - - -
M.S. N V.S. R IV 3,5,6 4,5,6 14,15,16
M.S. M V.S. R IV 3,4,5,6 4,5,6 14,15,16
M.S. Sev. & V.S. R VI 3,4,5,6 7,8,9,10 14,19,20
V. Sev.
Str. N V.S. R VI 3,5,6 7,8,9,10 14,20
Str. M, Sev. V.S. R VI 3,4,5,6 7,8,9,10 14,19,20
- & V. Sev. - - - - - -
Steep M, Sev.  V.S. R VII 3,4,5,6 7,8,9,10 14,19,20
- & V. Sev. - - - - - -
N.L. N S&M. S I 9 1,5,6 14,20
N.L. N S&M V.S. II 6 2,5,6 14,20
N.L. M S&M S II 4 2,5,6 14,20
G.S. N S&M M II 3 2,5,6 14,15,16
G.S. M S.&M. M III 3,4 3,5,6 14,15,16
G.S. Sev. & S.&M. M VI 3,4 7,8,9,10 14,19,20
- V. Sev. - - - - - -
M.S. N S.&M. R III 3,6 3,5,6 14,15,16
M.S. M S&M R III 3,4,6 3,5,6 14,15,16
M.S. Sev. &  S&M R VI 3,4,6 7.8.9.10 14,19,20
V. Sev.
Str. N S&M R IV 3,6 4,5,6 14,15.16
Str. M S&M R IV 3,4,6 4,5,6 14,15,16
Str. Sev &  S&M R VI 3,4,6 7,8,9,10 14,19,20
- V. Sev  - - - - - -
Steep N S&M R VI 3,6 7,8,9,10 14,20
V. Steep - - - - - - -
Steep M S&M R VI 3,4,6 7,8,9,10 14,19,20
V.Steep
Steep Sev &  S&M R. VI 3,4,6 7,8,9,10 14,19,20
V.Steep V.Sev.

Moderately Coarse, Medium, Moderately Fine, and Fine Textured Soils -- Shallow

1. Surface soil texture is not a major factor keeping the soil out of Class I.

2. The best land capability class for shallow soils is Class III.

3. Depth is a major factor and the best land class is Class III.

4. Slope of less than 1 percent is not a major factor.

5. Slope of 1 to 3 percent is a major factor, but will not lower the land capability class.

6. Slope over 3 percent is a major factor and will lower the land capability one unit.

Table 3. Coarse Textured Soils -- Deep and Moderately Deep

Slope Erosion Perm-
eability		 Surface
Runoff		 Capability
Class		 Factors
that keep
land out
of Class I		 Vege-
tative
Treatment		 Possible
Mechanical
Treatment
use one
or more
N.L. N S&M S III 2 3,5,6 14,20
N.L. N V.S. S III 2,5 3,5,6 14,20
N.L. M S IV 2,4 4,5,6 14,20
G.S. N - M III 2,3 3,5,6 14,15,16
G.S. M - M IV 2,3,4 4,5,6 14,15,16
M.S. N - R IV 2,3,6 4,5,6 14,15,16
M.S. M R IV 2,3,4,6 4,5,6 14,15,16
Str., Steep& N,M, &  R VI 2,3,6, 7,8,9,10 14,19,20
V.Steep Sev  also 4 if eroded
Str.Steep  V.Sev R VII 2,3,4,6 7,8,9,10 14,19,20
&V.Steep

Table 4. Moderately Coarse, Medium, Moderately Fine, and Fine Textured Soils--Very Shallow.
 
Slope Erosion Perme-
ability		 Surface
Runoff		 Cap-
ability
Class		 Factors
that keep
land
out of
Class I		 Vege-
tative
Treatment		 Possible
Mechanical
Treatment
use one
or more

All All All All VII 5 if V.S 7,8,9,10 14,19,20
2 in all cases
3 if sloping
4 if eroded
6 if rapid
runoff

Table 5. Special Factors (conditions) Deep Soils.
 
Slope
Erosion
Permeability
Surface Runoff
Capability Class
Factors that keep land out of Class I
Vegetative Treatment
Possible Mechanical Treatment use one or more
All All All Mod. Wet II 7 2,5,6 14,18
All All All Wet V 7 7,8,9,10 14,20
All All All Flooding V 8 7,8,9,10 14,20

7. Moderate erosion is a major factor that will lower the land capability class on 0 to 1 and 1 to 3 percent slope.

8. Moderate and severe erosion will be checked as a major factor on 3 to 5 percent slope, but it will not lower the land capability class.

9. Very severe erosion is a major factor that will lower the capability class by one unit.

10. Very slow permeability is a major factor but it will not lower the land capability class.

11. Very slow or rapid runoff will be checked as major factors, but they will not lower the land capability class.

12. Mechanical practices 15 (terrace) and 16 (terrace maintenance) are not used on slopes of less than 1 percent, even though the land capability class is Class III.

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