Citation

 

Originator: Dane County and Natural Resources Conservation Service (NRCS)

Publication Date: 2003

Title: Land Evaluation for Undrained and Drained Soils

Publication Information:

Publication Place: Madison, WI

Publisher: Dane County and Natural Resources Conservation Service (NRCS)

 

 

 

Layer Description

 

This layer was created by joining tables with Land Evaluation information by soil map unit with the soils polygon layer. Land Evaluation (LE) is a component of the Land Evaluation Site Assessment (LESA) system and rates the soil-based qualities of a site for agricultural use. The factors used to determine agricultural Land Evaluation were developed by the NRCS with cooperation from the Dane County Land Conservation Department. Ratings were based on information from Land Evaluation and Site Assessment: A Guidebook for Rating Agricultural Lands, Second Edition, published by the Soil and Water Conservation Society (1996).

 

Land Evaluation ratings for each soil map unit were created based on three factors:

1. prime farmland (10%)

2. soil productivity for corn and alfalfa (45%)

3. land capability class (45%)

 

For somewhat poorly drained, poorly drained, and very poorly drained soils the value for each factor depends on whether or not the soils are drained. Therefore two tables were created; one with undrained conditions and one with drained conditions. Ratings were separated into one of eight agricultural groups with arbitrary divisions. The soils in Group I are the best soils for agriculture. Note that these ratings are examples only.

 

 

Table Attributes

 

ITEM NAME WIDTH OUTPUT TYPE #DEC

SMU 9 9 C -

CAPUNIT 9 9 C -

CAPRATE 8 9 F -

PRIME 8 9 F -

CRNYIELD 8 9 F -

ALFYIELD 8 9 F 1

CCALC 8 9 F -

CACALC 8 9 F -

ACALC 8 9 F -

CGROUP 8 9 F -

CAGROUP 8 9 F -

AGROUP 8 9 F -

 

SMU Soil map unit. See Soil Survey for Dane County, Wisconsin published by the Natural Resources Conservation Service (NRCS).

 

CAPUNIT Capability Class from the USDA-NRCS-Wisconsin Technical Guide, Section 2, Dane County Soil Descriptions Non-Technical, pages 1-28, 1/19/96. It is described as the land capability subclass and may vary depending on whether or not the soil is protected from flooding and/or if it is drained. An asterisk denotes the class for a drained condition. Note that a different capability class (than the Technical Guide lists) was used for the Or, RaA, and VwA soil map units in their drained condition; the area NRCS Resource Soil Scientist assigned a capability class of 2W (instead of 1).

 

 

CAPRATE Numeric rating assigned to each land capability class (capunit above).

land capability class

factor scale (rating)

1

100

2S

97

2E

96

2W

92

3E

82

3W

78

3S

74

4E

68

4W

64

4S

60

5W

50

6E

30

6W

25

6S

15

7E

10

7W

10

7S

10

8W

0

8S

0

 

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


PRIME Prime Farmland from the USDA-NRCS-Wisconsin Technical Guide, Section 2, Dane County Soil Descriptions Non-Technical, pages 1-28, 1/19/96. The value was assigned either a 0 (not prime farmland) or a 1 (prime farmland). The value may vary depending on whether or not the soil is protected from flooding and/or if it is drained.

 

 

CRNYIELD Corn Yield (bushels of grain per acre) from the USDA-NRCS-Wisconsin Technical Guide, Section 2, Dane County Cropland Interpretations Yields per Acre, pages 1-15, 1/19/96. Corn yield equals zero for areas that are not drained and/or not protected from flooding. The maximum corn yield for soils in Dane County is 160 bushels per acre.

 

 

ALFYIELD Alfalfa Yield (bushels of grain per acre) from the USDA-NRCS-Wisconsin Technical Guide, Section 2, Dane County Cropland Interpretations Yields per Acre, pages 1-15, 1/19/96. Alfalfa yield equals zero for areas that are not drained and/or not protected from flooding. The maximum alfalfa yield for soils in Dane County is 5.8 tons per acre.

 

CCALC Final numeric LE rating using three factors: prime farmland (10%), soil productivity for corn (45%), and land capability class (45%). Note that formula uses productivity for only corn. Rating = (prime soil (0 or 1) x 10) + (corn yield / max. corn yield x 45) + (capability class scale factor x .45)

 

 

CACALC Final numeric LE rating using three factors: prime farmland (10%), soil productivity for corn (45%), and land capability class (45%). Note formula uses productivity for both corn and alfalfa. Rating = (prime soil (0 or 1) x 10) + [(corn yield / max. corn yield + alfalfa yield / max. alfalfa yield) / 2] x 45) + (capability class scale factor x .45)

 

 

ACALC Final numeric LE rating using three factors: prime farmland (10%), soil productivity for corn (45%), and land capability class (45%). Note formula uses productivity for only alfalfa. Rating = (prime soil (0 or 1) x 10) + (alfalfa yield / max. alfalfa yield x 45) + (capability class scale factor x .45)

 

CGROUP Final LE Group using CCALC ratings (see above). Ratings were separated into one of eight agricultural groups (with arbitrary divisions) with the soils in Group I as the best soils for agriculture.

group

final rating

I

93 100

II

85 92

III

74 84

IV

64 73

V

54 63

VI

40 53

VII

21 39

VIII

0 20

 

 
 

 

 

 

 

 

 

 

 

 


CAGROUP Final LE Group using CACALC ratings (see above). Ratings were separated into one of eight groups (see table above) with the soils in Group I as the best soils for agriculture. This group is used to display LE Groups in maps.

 

 

AGROUP Final LE Group using ACALC ratings (see above). Ratings were separated into one of eight agricultural groups (see table above) with the soils in Group I as the best soils for agriculture.