Crop equivalent ratings computed by the University of Minnesota's Department of Soil, Water and Climate have been superseded by Crop Productivity Index ratings from the Natural Resources Conservation Service. The Department no longer computes or supports CERs, and is working with county assessors on the transition from CER to CPI ratings -- this transition will take several years. The information on this page is provided solely 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.
For details on how CERs were computed, see two publications from the University of Minnesota's Agricultural Extension Service (note that all of the contact info in these documents is out-of-date):