Crop Equivalent Ratings (CER)

Crop equivalent ratings computed by the University of Minnesota's Department of Soil, Water and Climate have been superseded by Crop Productivity Index ratings from the Natural Resources Conservation Service. Information about CERs is provided here for historical completeness.

Crop equivalent ratings measured relative agricultural profitability across different soils; they were useful in comparing land parcels for purchase, rent management or tax assessment. CER values were computed for over 50 Minnesota counties (see status map) by the University of Minnesota's Department of Soil, Water and Climate using data on soil properties, climate, prevalent crop combinations, market value of crops and costs of production. Ratings ranged from 0 (low) to 100 (high).

CERs were specific to Minnesota; many other states used their own versions of soil productivity ratings. For an overview, see Development and Use of Soil Productivity Ratings in the United States, J.H. Huddleston, Geoderma 32 (1984) 297-317.
 

Computing CERs

For details on how CERs were computed, see two publications from the University of Minnesota's Agricultural Extension Service:

• Soils Fact Sheet No. 34-1980 (PDF, 48K, 2 p.)
• Productivity Factors and Crop Equivalent Ratings for Soils of Minnesota (PDF, 911K, 20 p.). The link is to the first 16 pages of the manual.