You can now assess your corn’s nitrogen (N) needs every 24 hours. The Adapt-N online computer model, from Cornell University, simulates the complex processes in a corn field: local precipitation and temperatures, soil type, soil organic matter and slope, previous crops, inputs, tillage, planting date, population, hybrids, rotation, type and date of starter and yield potential. Using high-resolution weather information (3x3-mile grids), the web model tailors site-specific N recommendations to your farm in almost real time.

Adapt-N enables N to be sidedressed as weather events unfold, reducing the application of N early in the season.

“Adapt-N allows you to explore various what-if scenarios, in addition to providing real-time answers during the growing season,” says Jerry Hatfield, director, National Laboratory for Agriculture and the Environment, Ames, Iowa. “You can also replay the growing season and see whether you did the right thing.”

The most recent 2012 Adapt-N results from Iowa show 36-lbs./acre average N input reductions, with no significant yield reductions in 95% of the cases. These data come from 19 (drought year) 2012 Iowa trials. There was a profit advantage over conventional N rates in 74% of the trials (by $1.49-$81.20/acre).



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“Adapt-N could not predict the July Iowa droughts and associated yield losses by sidedress time, but it still recommended lower rates than normal by incorporating the dry early-season conditions.”

Over the 2012 growing season, 61 trials indicate that:

  • Grower profits increased on average by $17/acre in Iowa trials and by $32/acre in New York with the improved 2012 Adapt-N model version.
  • N application rates were significantly reduced in almost all cases, by 54 lbs. N/acre on average, substantially reducing post-growing season losses of excess N to the environment.
  • Any yield losses were generally negligible (minus 1 bu./acre average across all trials), despite the reduced N inputs
  • Higher N recommendations were justified by higher yields when drought was not the greater limiting factor.
  • 77% of Adapt-N recommendations provided increased grower profits over current rates in 2012, when including inadequate expected yield inputs; 87% when these are excluded.
  • Model inputs, especially yield expectation, must be carefully chosen to represent field-specific conditions.

In all, growers can realize large savings with the use of Adapt-N, which also provides strong incentives to shift the bulk of N applications to sidedress time, and will decrease long-term environmental losses.