Surety's Soils Map utilizes the latest soils data from the USDA NRCS Soil Survey Geographic SSURGO database for
the Continental US and displays it in an easily understood format for Ag related uses.
The Iowa Corn Suitability Rating (CSR) originally developed in 1971
is an index procedure to rate each different kind of soil for its potential row-crop productivity. The CSR Rating is
intended to measure one soil’s yield potential against another over time.
All soils start at 100 and points are deducted for land conditions such as slope, water and climate.
In the summer of 2012 USDA NRCS began replacing the CSR values with CSR2 values developed at Iowa State University. CSR2 is
an effort to make ratings more consistent, easier to calculate and the values more transparent to the public. For more information
refer to the following:
Explanation of the original CSR:
An Iowa State University presentation discussing CSR2:
In order to assist in the transition from CSR to CSR2 Surety Soils Maps will continue to provide CSR values
for the foreseeable future.
Illinois Bulletin 811
The Bulletin 811 was developed by the University of Illinois to provide crop yields and productivity indices under an optimum
level of management. The optimum productivity index (PI) can be used
to determine the prime agricultural class of any soil type in the state.
More information on the Bulletin 811
Productivity Index (PI)
The PI is available in North Dakota, South Dakota and Minnesota. The productivity index (PI) model is a
derived measure of soil productivity. The basic assumption of the PI model is
that crop yield is a function of root development, which in turn is controlled by the soil environment.
Nebraska Soil Rating for Plant Growth (SRPG)
Soils maps in Nebraska provide the SRPG Rating which was developed by USDA-NRCS staff members to rate
soils suitability for plant growth at the county level. SRPG is based on twenty-five soil properties and landscape features.
The system rates the major soil characteristics (physical, chemical, and biological) that are important for crop growth.
Irrigated and Non-Irrigated Class Soils
Land capability classification is a system of grouping soils
primarily on the basis of their capability to produce common cultivated
crops and pasture plants without deteriorating over a long period of time. Surety's Soils
Maps provide these classifications for all states in the Continental U.S.
Crop Yield Ratings
Crop yield ratings from the Natural Resources Conservation Service (NRCS) provide a relative
ranking of soils based on their potential for intensive crop production.
An index can be used to rate the potential yield of one soil against that of another over a period of time.
Surety's Soils Map allows you the option to customize which crops you want to include in your reports.