Illinois Bulletin 811 is a supplement to Bulletin 810. It contains another set of crop yield estimates for all Illinois Soils under the Optimum level of Management. "These yields were a 10 year average of what was achieved by the top 16% of farmers in Illinois in the 1990's." (University of Illinois at Urbana-Champaign)
In the Surety Soils Maps, the Indexes are adjusted for slope and erosion according to Bulletin 811 Table S3.
When selecting to display the Optimum Crop Productivity Ratings for Illinois Soils, it will supersede the NRCS Crop Yield Information when selected in the
Soils Report Options.
 Illinois Bulletin 811 Soil Data Map |
Crop yields and productivity indices for optimum management (B811) are maintained at the following NRES web site:
https://www.ideals.illinois.edu/handle/2142/1027
The data was updated to reflect growing conditions from 2000 - 2009 on 1/2/2012.
Bulletin811
Sources:
University of Illinois at Urbana-Champaign, . "Optimum Crop Productivity for Illinois Soil." Bulletin 811. N.p., n.d. Web. 21 Nov 2014.
Bulletin811.pdf.
See Also: