Published on Friday, February 03, 2017
I’ve received a few calls over the past few weeks from wheat farmers inquiring whether or not their wheat fields were starting to break dormancy. From what I’ve seen, the answer is yes. Many wheat fields have in fact “greened up” over the last couple of weeks. With temperatures reaching the mid-60s on January 21 and 22, and nighttime temperatures remaining above freezing until around January 26, a definite change has taken place across southern Illinois wheat fields. However, this is not a cause for alarm. It seems that we experience a warm spell in late winter that begins to green up the wheat almost every year. The return to more seasonal temperatures around January 25 will help the wheat crop regain some of its winter hardiness.
With February underway, many wheat farmers will now be looking to make a nitrogen (N) application. One thing to consider before making your application is the potential loss of N if your applications are made on frozen ground, and are followed by a heavy rain event. Especially on the rolling acres of southern Illinois, this could result in the loss of a large portion of your N, so be mindful of the weather forecast when these early applications are made.
Despite the cold temperatures in February, it’s still a good idea to scout your wheat fields ahead of these applications to determine how much N is needed. Counting tillers per square foot (tillers/sq. ft.) is a great way to determine N needs. The University of Kentucky recommends that the ideal count is 70 to 100 tillers/sq. ft. Beck’s Practical Farm Research (PFR)® has shown that a split application of N (UAN or urea) has shown a positive return on investment of $23 to $33/A., respectively. With the wet conditions we’ve experienced the last few spring seasons, split applications of N have been economically beneficial. Ideally the first application should be made around Feekes 3, when tillers are formed. Because of good fall growing conditions, there are some wheat fields that may be past this growth stage, but most fields throughout southern Illinois should be around this stage. The remainder of N should be applied at Feekes 5, just before jointing where the leaf sheaths are strongly erect.
Split-applications are important for two reasons. First, a split application protects the plant from N loss, allowing more N to be available to the plant. Second, an early N application promotes tillering. Ideally, I would like to see the main stem and two to three tillers per plant. When scouting, if your tiller counts are acceptable (70 to 100/sq. ft.), then 30 to 40 units/A. of N should suffice. If tiller counts are short (less than 70 tillers/sq. ft.), applying 60 units/A. of N at this stage will help promote more tillering. Applying the remainder of N at Feekes 5 is important because at that point, a rapid uptake of N begins. At Feekes 5, the plant’s yield potential has already been determined, so delaying the second application past this stage will likely not improve the crop yield. Beck’s PFR data tells us that around 120 units/A. of N is our economic optimum N rate (EONR) in southern Illinois. Therefore, applying 40 units at Feekes 3 and another 80 units at Feekes 5 will create a sound N management plan.
Take the time to scout your wheat and plan out your N applications ahead of time to ensure your wheat crop is off to a good start this spring. If you have any questions, please contact myself, your local see advisor or dealer.
Sean Nettleton | Field Agronomist
Author: Sean Nettleton
Categories: Agronomy, S Illinois
Tags: Practical Farm Research, Wheat, Illinois Agronomy, PFR, tiller counts, nitrogen management, Sean Nettleton, AgChat