Thinking nitrogen for the spring
The snow is gone and summer is here? The change in weather this spring has allowed for earlier field work to begin. Questions that come to mind include what kind of tillage should I do and do these condition affect me nitrogen management program for corn.
Tillage for this spring.
Last fall tillage was difficult at best to do because of the dry conditions. Large, hard clods were created with the fall tillage. It looks like the moisture, we did get this winter did mellow the clods enough that a tillage operation will be able to create a good seedbed this spring. One thing to keep in mind, unless we get a large amount of rain this spring, do not over till your fields. Tillage will dry the soil out and cause a dry seedbed. This will cause problems with plant stands and thus effect grain yield even if we receive adequate amounts of moisture during the growing season.
With field conditions rapidly improving there likely will be nitrogen applicators getting into fields. What about the nitrogen management problem for corn production in 2012?
What should I expect if I put on my nitrogen last fall?
It's true that field conditions were less than optimum for N application last fall. The dry soil conditions made it difficult for fall anhydrous ammonia application and the incorporation of urea. There are many questions about the status of that nitrogen. Will you need to make a supplemental N application this spring? At this point there is no good way to assess the amount of N in the soil. Soil sampling for soil nitrate-N at this time is unreliable and will likely not give an accurate picture of what is still contained within the soil. The soils have started to warm. At this point in time (March 18), we would not expect a large amount of conversion of ammonium to nitrate within the soil if the fall applications were applied according to NBMPs, such as application when soil temperatures are less than 50 degrees and the anhydrous band was sealed and did not volatilize out of the soil after application. The best option at this point would be to wait and plan on a side-dress application. This side-dress application would be planned based on the supplemental N application decision tool developed by the University of Minnesota. Check www.extension.umn.edu/nutrient-management for more information.
I did not apply N last fall, should I be applying N this early?
Soil conditions do appear to be ideal for application but there still is some risk associated with application this early in the season. First, if you have sandy soils you should not consider early application. Nitrogen applied as part of the starter and a side-dress application is the best practice on sandy soils.