Soils

The corn crop in Illinois is off to a good start in many fields, and in most areas is in the V5 to V8 growth stages, just starting its rapid growth phase. On average, the crop under good conditions will add some 200 lb of dry matter per acre per day over the next 80 days or so. It will take up 3-4 lb per day of nitrogen before pollination, after which the N uptake rate will slow.…

While dry weather is allowing N application to start in some places in Illinois, the ongoing cool temperatures continue to raise questions about N management this spring.
With help from the Council on Best Management Practices (C-BMP), we are organizing a webinar for Thursday, March 27 at 8:00 AM to address some of these issues, including fate of fall-applied N, use of inhibitors this spring, and how cool soils might affect soil N supply and plant uptake.…

We hope that we’ve seen the last of the snow by now, but both air and soil temperatures remain below average in Illinois heading into the second half of March. According to the Illinois State Water Survey (http://www.isws.illinois.edu/warm/soiltemp.asp) minimum temperatures 4 inches deep under bare soil ranged from the low 30s in northern Illinois to the mid-30s in southern Illinois the morning of March 17, and with some sunshine on that day, reached the upper 40s to low 50w in southern Illinois but did not get above the low 30s in the northern part of the state.…

With 85 percent of soybean and 74 percent of corn acres harvested by October 27, the annual process of deciding when and how to supply nitrogen fertilizer for the 2014 corn crop is underway.
Lessons from this past year
Following the very dry first half of 2012 and low corn yields, soil sampling last fall revealed an average of about 80 lb N present as nitrate in the top foot of soil in Illinois. With a lot of rain in late winter and early spring,…