Nitrogen shortages may require sidedress or other option

Extreme winter conditions slowed river barge deliveries and rail shipments of nitrogen this spring. And, while most South Dakota producers will have their nitrogen needs met this spring, some may have to consider other application management options due to nitrogen shortages, said Anthony Bly, SDSU Extension soils field specialist. This is even with railroads recently promising faster fertilizer delivery.

Addressing the situation with South Dakota farmers, Bly said, "It is extremely hard to tell where shortages might occur until strong consumption applies stress on supply. If shortages occur in your area don't despair as there are other options."

He pointed out that corn and wheat don't require large amounts of nitrogen early in the growing season because uptake is related to plant dry matter accumulation and grain development.  

According to the Iowa State University Extension publication, "How a Corn Plant Develops," 50 percent of the required nitrogen has not yet been taken up by the plant at the R1 growth stage (silk).

"Getting a portion of the nitrogen applied at planting and using top dress or sidedress nitrogen applications for the balance of nitrogen needs, has been shown to be very effective and efficient management tools," Bly said.

Most nitrogen application timing experiments throughout the Great Plains have shown similar and even higher yields between comparisons with later applied nitrogen such as top dress and sidedress, Bly explained.

"A long-term corn nitrogen timing study in South Dakota has shown the sidedress application to result in similar or even higher grain yield compared to a North Dakota wheat N timing study," he said.


Getting nitrogen to the plant, in the form required, and when the plant needs it, is not only good for plant health, Bly said, it's also good for the environment by reducing the chances for entry into water systems.

He points to the 4R's for nutrient stewardship - Right source, Right Rate, Right Place and the Right Time, which were developed by the International Plant Nutrition Institute (IPNI) and several other organizations. "Understanding crop nitrogen use and uptake is a huge part of knowing how the 4R's for nutrient stewardship can be used for more efficient nutrient utilization," he said. "If you find yourself with short nitrogen supplies at planting time this spring, don't worry, later season nitrogen applications have been shown to be very effective, efficient and better for the environment."

To assist with timely application of nitrogen, Bly encourages growers to consult their private or ag retailer agronomist.

"Agronomists can also introduce you to other methods for nitrogen application and management that you may not have used before," he said.