Soil Fertility - Nitrogen

I think nitrogen management may be the topic I have written about most. In our seminar on Friday, the most covered topic was nitrogen management. Everyone wants to manage nitrogen in such a way that they maximize corn yields.  With concerns about Chesapeake Bay, Lake Erie, and Gulf Hypoxia, good nitrogen management is also needed to be environmentally sound in our practices.  In addition, many people are concerned about the nitrous oxide released into the atmosphere.

Testing for nitrogen to determine rates can be done in a number of different ways.  Our Soil Health Test can help determine how much nitrogen release to expect from the soil.  The Presidedress Nitrate Test can help determine if additional nitrogen is needed at sidedress time, or at any time you can apply.  The stalk nitrate test, done after black layer, can help determine if the crop had too much, too little, or enough nitrogen available to take the crop to maturity.  Nitrogen sensors are available if you are comfortable with them to do rescue treatments on wet soils.

Setting a base rate is also a challenge.  Emerson Nafziger made a good case for using the Nrate calculator to initially determine how much to apply.  He did present some information to show that producers can come up just a bit short with the Nrate calculator.  One way to adjust for that issue would be to go with the maximum rate on the chart instead of the average rate. I was not overly impressed with the results of using the Adapt-N program.  The bottom line is, some producers should be looking to low nitrogen rates to be more environmentally sound.  If you are still looking for ways to cut back on inputs this year, the Nrate calculator might help you make sound decisions about the economics of your nitrogen rates.