Oct 25, 2010  |  Today's News |  Conservation

Now more than ever, the practice of fall-applied Nitrogen is under the microscope in Illinois. Regardless of individual farmer opinions on the matter, the fact is that environmental interests have turned this particular farming practice into the “hot button” issue in Illinois right now. Best Management Practices for fall-applied N have been recommended by IL Corn and most farm groups, along with the IL Fertilizer and Chemical Association. See the map in this post for the latest soil temps in your area. Compromising the integrity of the industry at this point could very well compromise fall-applied N for everyone in Illinois.

Click 10am 4-Inch Bare Soil Temperature Map (° F) for the latest information on soil temps.

The future of fall-applied N in the state of Illinois depends on YOU. Do what’s right.

The IL Fertilizer and Chemical Association recommends using nitrogen stabilizers for ALL fall-applied N.

Wait until after October 15th before even considering N application.

Only apply N when the soil temps are in the low 50’s and the longterm forecast is for sustained cool weather.

If you choose NOT to use an N stabilizer, only apply N when soil temps are below 50 degrees and will stay that way.

The Illinois State Water Survey, through a grant from the Illinois Department of Agriculture Fertilizer Research and Education program, has initiated daily dissemination of maps showing 4-inch bare soil temperatures across the state based on observations taken at selected Illinois Climate Network sites. These data are intended to assist Illinois farmers with timing of post-harvest nitrogen (N) fertilizer application. The information displayed is specifically representative of the actual locations where soil temperature observations are made. Elsewhere, these data should be viewed as a guide to general soil temperatures within a given region, and as indicative of current temperature trends progressing across the state. Farmers and applicators should monitor the soil temperature of each field before fall application of N fertilizer.

Individual daily maps are analyses of the observed soil temperatures across Illinois on the previous day at a depth of 4 inches below a bare soil surface. Figures show:

soil temperature between 9:00 a.m. - 10:00 a.m. (Central Standard Time) on the previous day

daily (midnight to midnight) maximum soil temperature on the previous day

daily (midnight to midnight) minimum soil temperature on the previous day

Charts will be updated by 4 am each day.

Users should be aware that soil temperature fluctuations during the fall may result in periods with soil temperatures below the accepted threshold for N application followed by an extended period with soil temperatures above the accepted threshold. Therefore, users are advised to be aware of both the current soil temperature and short- to long-term weather forecasts.