How Much Nitrogen Do I Need?

Nitrogen availability near flowering time and during grain fill is one of the most important differences in final yields. Leaching and wash off of surface applied N, on wetter or compacted soils, has led to some later planted fields showing yellowing and stunting. This is more noticeable in continuous corn fields. These stunted plants will also have shallow roots which makes it impossible to explore the available N in the deeper root system. Side dressing of small amounts of N could lead to yield increases, but it can take a while to get the active roots to reach the nitrogen. Foliar feeding can be helpful to get the plants actively growing, so they can reach the available N. This is due partially to the fact that some surface nitrogen was lost and also that roots stayed shallow due to a lack of oxygen during the cold period. Now that temperatures are hot, plants may soon be suffering from lack of moisture in the surface root zone. Early planted corn has a deeper root system and can more completely access the N in the deeper soil profile. Since Nitrogen is so important to your corn crop, the use of the Corn Nitrogen Rate Calculator web tool will help guide you toward maximum profitability as the price of corn and the price of Nitrogen vary, but it only works if the nitrogen is not lost before the plant gets to it.

If you haven’t used it, check out the ISU extension Ag Decision Maker website: http://www.extension.iastate.edu/farmmanagement/.  This is a great tool to know your costs and to help you put together a marketing plan for the crops you manage, so that you remain profitable and sustainable.  There are many input costs which you can control and the use of these tools emphasizes the need for a good marketing plan that is proactive, rather than reactive.  If you followed a marketing plan and sold a portion of your corn or soybean prices in early January of 2020, you were well rewarded this year. Due to a lot of downside price risk, 2020 is a great year develop a marketing plan that covers your variable production costs and will automatically react to weather or demand driven pricing opportunities. This will allow you to run a more sustainable farming operation and make informed acreage adjustments by crop, for 2021.Next year you may also want to grow more new high yielding conventional corn from Miller Hybrids, to improve your ROI.

-Bob Miller

President & Owner