CAN YOU AFFORD TO TAKE RISKS WITH YOUR NITROGEN?
There has been a lot of discussion on nitrogen timing and the best methods to apply nitrogen. The University of Missouri states it well, “The BMP for timing of nitrogen (N) fertilizer applications is to apply fertilizer as close as possible to the period of rapid crop uptake (Figure 1). Managing N in this way will minimize losses of N from the field and will ensure adequate N availability to the crop during critical growth periods.”
In addition, the University of Purdue states that ear size is first determined at V5-V6; “Kernel row number determination of the uppermost ear begins shortly after the ear shoot is initiated (V5 to V6) and is thought to be complete as early as V8.”
Therefore, we know that the primary goals of applying nitrogen is to apply it as close to when your crops need it as possible and also to apply it in a way that will minimize your risk of nitrogen loss to ensure nitrogen is in the soil, available for your crops when they need it.
First let’s take a look at nitrogen timing
- If you apply all your nitrogen in the Fall you will have around 7 months from when you applied nitrogen to when your crops need it. This seems to be a big gamble and puts you at the mercy of weather to ensure that your nitrogen is still there and available in the Spring. If you get heavy rains in the Fall or Spring, you could lose a very significant portion of your nitrogen through leaching, which is also not as environmentally friendly since this nitrogen has nowhere to escape but deeper into the soil.
- If you apply all of your nitrogen pre-plant you have cut down on some of your risk of nitrogen loss but you are still applying 1-2 months before your crops need it so there is still some unnecessary risk of nitrogen loss through leaching.
- If you wait to apply a significant portion of your nitrogen until mid-summer right before the reproductive stage, you may not have all of you nitrogen needs met at V5-V6 when ear size is determined and you may have starved your crops during the early critical growth stages that give a baseline for future yield. In addition, what individuals pushing late-season side dress do not mention is that the microbes and organic matter in your soil contain a significant amount of nitrogen that is naturally released as the soil warms up through the summer.
Therefore, early sidedress strikes the perfect balance between applying your nitrogen just before it is needed by your crops and also ensuring that all of your crops nitrogen needs are met during the critical growth stages.
Next, let’s take a look at nitrogen application methods, Dribble vs. Injection
The University of Purdue states that as much as 15-20% of surface applied urea-based nitrogen may volatilize (lost) within a week after application. They also stated that this risk is essentially zero if the product is injected into the soil.
If your nitrogen is applied on top of the soil you are relying on rain to take the nitrogen down to the roots where it is need for uptake. If we have a dry period in the summer, you are subjecting your nitrogen to significant risk of volatilization as it will convert into ammonia gas and escape into the atmosphere, never to be utilized in boosting the yield of your crops.
Injecting your nitrogen in the soil helps reduce this risk of volatilization and helps ensure that the nitrogen that you apply will still be there when your crops need it most.
Our crops are dependent enough upon timely rain, why would we also build this into our Nitrogen Program? Inject your N with a FAST Applicator and minimize this risk!
The University of Purdue sums it up best by stating “One of the keys to managing costs of nitrogen fertilizer or maximizing nitrogen use efficiency is to manage N sources wisely to minimize the risk of nitrogen loss due to leaching, denitrification, or volatilization. The use of a sidedress application strategy remains one of the easiest and least expensive ways to maximize nitrogen use efficiency.”
Invest in your operations with a FAST Applicator to maximize your nitrogen investment and yield by providing a boost of N just before ear size is determined and also minimizing your risk of N Loss by injecting your Nitrogen IN THE GROUND rather than taking an unnecessary risk and dribbling it on top.
References
University of Purdue – https://www.agry.purdue.edu/ext/corn/news/timeless/CornRespLateSeasonN.html
University of Missouri – http://plantsci.missouri.edu/nutrientmanagement/nitrogen/practices.htm
University of Purdue – https://www.agry.purdue.edu/ext/corn/news/timeless/earsize.html
Montana State University – http://store.msuextension.org/publications/AgandNaturalResources/EB0209.pdf
University of Purdue – https://www.agry.purdue.edu/ext/pubs/2006NLossMechanisms.pdf