The weather has left fields not only inaccessible but has also created problems for river and rail transportation, which are now facing increased pressure to deliver fertilizer products farmers will need once it finally dries out. These factors have culminated in increased risk for a compressed spring fertilizer season and should force many growers to think about contingency plans for their planned nitrogen fertilizer programs.
There are many options for successful nitrogen management, thanks in part to the availability of enhanced efficiency fertilizer (EEF) technologies. We know wet spring conditions can increase the risk for leaching, denitrification and volatilization losses of nitrogen, all of which can threaten a grower’s bottom line. Here’s how solutions from Koch Agronomic Services can help mitigate the risk of nitrogen loss this spring.
Scenario One: Spring Anhydrous Ammonia
If time and logistics allow, apply nitrogen originally planned as pre-plant anhydrous ammonia, stabilized with CENTURO® nitrogen stabilizer. CENTURO is designed to protect nitrogen from leaching and denitrification losses. A multi-state, multi-year study showed that spring applications of anhydrous with CENTURO yielded 6 bu/acre of corn more than untreated spring anhydrous.1 
Scenario Two: Spring Anhydrous Ammonia is Delayed or Unavailable
If there could be a potential delay in the delivery and application of ammonia, a grower should consider the following as pre-plant alternatives:
- All or a portion of the nitrogen can be applied as a weed and feed application with pre-plant, pre-emergence or burndown herbicide. Remember, broadcast UAN is subject to volatilization loss and should be treated with a urease inhibitor, such as ANVOL® nitrogen stabilizer.
- All or a portion of the total nitrogen can be applied as broadcast urea. Volatilization losses with urea can approach 40% of applied nitrogen and should be protected with ANVOL.
- All or a portion of the total nitrogen can be applied as broadcast SUPERU® fertilizer , which has the same nitrogen content as urea and features integrated dual inhibitors to minimize all three forms of nitrogen loss.
Across 8 site-years with locations in Virginia, Kentucky, Illinois, and Tennessee, urea treated with ANVOL resulted in a 31 bu/acre corn yield advantage over untreated urea.2
- Urea treated with ANVOL consistently resulted in higher yields starting at 60 lbs N/acre.
- Urea treated with ANVOL resulted in a 31 bu/acre average corn yield advantage over untreated urea.
- Based on sites responsive to nitrogen fertilizer and where losses to volatilization were a significant factor.
- Bars with the same letter are not significantly different (p<.10).
Scenario Three: Optimal planting date is near or passed
A 22-site year study on corn conducted by the University of Illinois showed corn yield was maximized when planted in mid-April to early May. Planting on May 10 reduced yield by 5% and yield decreased by almost 0.5% for every day planting was delayed beyond May 10 (through May 30)3. If soil conditions or delayed fertilizer availability pushes the planting window further out, growers should consider planting first and then applying nitrogen afterwards. Early post-planting nitrogen applications could be in the form of CENTURO treated anhydrous ammonia, broadcast SUPERU and urea or UAN treated with ANVOL. Early nitrogen applications are subject to loss prior to the rapid vegetative growth stage of corn.
Split nitrogen applications may help mitigate yield impacts of early season nitrogen loss and ensure that nitrogen is available during grain fill. Two-thirds of the nitrogen can be applied as either CENTURO-treated anhydrous ammonia, broadcast SUPERU or urea treated with ANVOL or injected UAN treated with CENTURO or ANVOL, either at planting or very early post-planting.
The remaining nitrogen can be applied as broadcast urea, dribbled UAN, injected UAN, or even injected anhydrous. Post-emergent surface applications of nitrogen as either urea or UAN are particularly vulnerable to volatilization loss and should be protected with a urease inhibitor, such as ANVOL.
Delaying nitrogen applications beyond early vegetative stages may reduce yield potential, especially in high yielding environments.
Research has shown that early season nitrogen is important to optimize yield potential for the primordial ear. Delayed applications may limit yield potential and can also carry the risk of nitrogen never getting into the plant due to the increased likelihood of dry surface conditions as we move later into the growing season.
Don’t leave one more thing to chance this season – protect your nitrogen and keep it where it belongs this spring. Contact your KAS representative or visit your local retailer to learn more and how we can help you make the spring season a successful one.
1The underlying data was provided by University of Nebraska, University of Missouri, and the Illinois Fertilizer and Chemical Association under Research Trial Financial Support Agreements with Koch Agronomic Services, LLC,. Neither the university nor the individual researchers referenced endorse or recommend any product or service. Improvements in yield may not be observed in all cases.
2The underlying data was provided by Virginia Tech, University of Kentucky, University of Tennessee, University of Illinois and Pike Ag, LLC under a Research Trial Financial Support Agreement with Koch Agronomic Services, LLC and neither these institutions, nor the individual researchers referenced, endorse or recommend any product or service.
3http://bulletin.ipm.illinois.edu/?p=3848, Planting date for corn and soybeans in Illinois, Emerson Nafziger, March 23, 2017.