The Open Window of Fall Abruptly Shut

The weather this fall was among the best many of us can remember. A long spell of dry weather and warm temperatures led to lower drying costs and great conditions for alleviating soil compaction with tillage. However, in early November this open window closed quickly and left many of us with acres not covered with fall fertilizer.

This year marked the first year in some time that I didn’t use anhydrous ammonia as part of my corn nitrogen program. My move to strip till with dry fertilizer meant I started before the soil temperatures were cool enough for ammonia. But for many farmers, harvest and tillage wrapped up by late October, and they looked at the ‘to-do’ list and geared up for fall ammonia. While air and soil temperatures were quite warm when the first tanks rolled, still most were able to seal adequately.

Missed Fall NH3 Application: Now What?
But, for many, the dry conditions turned very wet, and as a result, many weren’t able to finish their fall anhydrous. So, what does this mean for your fields next spring? Here are a few considerations as you adapt your plans:

  • Don’t Rush It Next Spring: Sometimes not being the first in the field with spring anhydrous can be good. You need to wait until the soil profile is dry enough all the way to the knife point. Otherwise, you can smear the knife track, trapping the nitrogen in narrow bands for much of the season. This is why you see streaking in many spring applied fields that might have been a little damp.
  • Be Patient with the Planter: I have witnessed several times when farmers planted within 5-7 days of N application with bad outcomes. The ammonia gas can burn seedling roots if pockets exist beneath the surface. Waiting at least a week or until a soaking rain is the best way to avoid setting back your crop from the beginning.
  • Consider Alternative Forms of N: If being patient is as hard for you as it is for me, switching to another form of N for spring applications might be the answer. Raw cost of materials is only one of the costs that need to be considered when choosing a nitrogen source. You are probably applying a pre-emergent herbicide, so using more N solution as the carrier is always an option and can save a pass across the field.
  • Don’t Skimp on Stabilizers: When you make the call to apply N next spring, avoid cutting out the stabilizers. If you apply N in the early part of April, or even late March, there is still a lot of time for the ammonia to convert rapidly to nitrate and be subject to loss from May rains. Corn doesn’t require much N until early June, so laying it all on the line betting against Mother Nature can be a risky move.

Advantages for Spring N
While you may feel like you’ve missed an opportunity, remember that with every challenge comes potential gain. As the markets continue to grind this winter, fertilizer prices have edged lower, and going into 2016 with lower input costs is a good thing.

Additionally, the mild winter so far is making farmers who applied N this fall nervous about what’s happening in the field. Soil temperatures have been in the high 30’s and low 40’s since the application window closed. At these temperatures, conversion to nitrate is slow but still occurring. Any acres applied last fall need to be monitored going into the summer to make sure we don’t short ourselves the N needed for maximum yield. This can be done quickly with 360 SOILSCAN or by sending samples to your soil-testing lab.

So whether you were able to get in in the fall or if you need to wait until spring, be informed about effects of N application timing in your field, and be ready to adapt based on what this El Nino year will bring.