As you know, this is the time of year to start thinking about topdressing winter wheat with some nitrogen (N), but Mother Nature isn’t cooperating in some parts of the southern Plains.
Parts of Oklahoma, Kansas and Texas are dealing with a pretty unrelenting drought. While it appears northern Kansas got some relief from rain and snow this week, the situation is still serious in western Oklahoma, southern Kansas and the eastern half of the Texas Panhandle. An updated U.S. Drought Monitor Map is scheduled for release today.
The good news is that there’s still time to topdress wheat before the lack of N affects yield potential, says David Marburger, small grains specialist at Oklahoma State University Extension.
If conditions are dry — and dry deeper than the majority of the rooting zone — the best option is to wait to apply topdress N right in front of a real chance of rain, he says. Ideally, N needs to be down in the rooting zone just prior to jointing.
But what you can do, Marburger advises, is apply N-rich strips to take the guesswork out of knowing if N needs to be applied and how much should be applied.
Some growers may have too much ground and can’t cover all of it just prior to a rain, or may feel a need to apply now due to concerns about N being limited after it does start raining. For no-tillers in that situation, the two big concerns are ammonia (NH3) volatilization with dry urea and tie-up on the residue with liquid UAN, Marburger says.
If there is tall standing stubble with dry soil below the dry urea gets the edge. Why? If the stubble is not in a mat, Marburger says, the urea prill can work its way down towards the soil surface.
“If it can get it there it’s out of the high winds, and it will remain there until we get a rain, heavy dew, or increase in humidity,” he says. There is still a chance for N loss due to volatilization, but it goes back to whether there is any chance a grower can wait until applying N.
One other idea: Since it’s dry and there’s still time to apply N, it may be the perfect year to topdress urea with a grain drill, Marburger adds. For those interested, research results from last year as well as a calibration guide, can be found by clicking here. And more information about nitrogen applications that are “thinking outside the box” can be found by clicking here.
