The USDA-funded Useful to Usable (U2U) project has released their split Nitrogen application decision tool for corn across the Corn Belt. The Corn Split N tool combines historical weather and fieldwork data with economic considerations to determine the feasibility and profitability of completing a second (split) N application within a user-specified time period. Check it out at www.agclimate4u.org under the “decision support tools”.
Screen shot with default values for Champaign County, Illinois
It is often repeated that the modern corn hybrids are less vulnerable to drought. Is it true? Well, yes and no. Emerson Nafziger, University of Illinois agronomist, has put together an analysis of corn yields between 1988 and 2012 in Illinois.
In his own words, here is what Emerson found:
“To look at how much yield was lost to drought in 1988 and 2012, I projected trend-line yields for each drought year based on yields over the 30 previous years. The expected (trend-line) yield for 1988 was 129 bushels per acre; the actual yield was 73, so the loss was 56 bushels per acre. In 2012, the expected yield was 173 bushels per acre and the estimated yield is 116, so the projected loss is 57 bushels per acre. Measured in terms of bushels per acre less than expected, the two years are almost identical.
The 1988 yield represents a loss of 44% of expected yield, while in 2012, with higher yield expected, the percentage loss was only 33%. So in relative terms, the 2012 crop lost less yield than the 1988 crop, but in absolute terms, losses were almost identical between the two years.
It’s not clear whether percentage loss or bushel loss is the better measure of drought effects, but what is clear is that serious drought continues to cause serious yield loss, even with today’s faster-growing, higher-yielding hybrids…”