Wallaces Farmer

Unlocking higher corn yields

Nitrogen is one of the most critical inputs for a corn crop’s success and is also one of the more challenging inputs to manage.

June 1, 2024

5 Min Read
Mastering the Art of Sidedress Applications
Submitted by Beck's Hybrids

Effectively supplying nitrogen to a corn crop is vital to raising higher yields and profitability. Split-applying nitrogen is one approach to help mitigate weather risks and ensure the plant has adequate nitrogen throughout the growing season. Management decisions, including timing, rate, depth, and additives will impact the effectiveness of your sidedress application of UAN and must be considered when developing your nitrogen plans each season.


Beck’s Practical Farm Research (PFR)® data shows that the V3 growth stage is the ideal time to sidedress corn. An efficient starter program of 30 to 60 units of nitrogen applied 2x2x2 with the planter coupled with the remaining nitrogen sidedressed at V3 has consistently been the highest-yielding nitrogen program in several different PFR studies. Multi-location results from Beck’s nitrogen systems study show that delaying the second nitrogen application until V6 has resulted in a loss of 3.2 Bu./A.


The yield advantage observed when sidedressing at V3 may be surprising, considering corn plants take up large amounts of nitrogen between the V8 and VT growth stages. Beck’s PFR data suggests that delaying your nitrogen application until this rapid growth time frame is not beneficial, as nitrogen must be applied before this high uptake period to be fully utilized by the plant and positively impact yield. Additional studies testing applications of nitrogen later in the season indicate that waiting to apply a portion of your nitrogen until V7 or after can negatively impact yield.


It’s important to remember that nitrogen moves into the plant with water in the nitrate form, and dry soil conditions will limit uptake. When it comes to timing, PFR data indicates that you are better off hedging early than too late. Letting a corn crop go through an extended period without enough nitrogen is a yield penalty you cannot compensate for later.


In Beck’s PFR studies, the economic optimum nitrogen rate in a corn-after-soybean rotation has been 183 to 202 lb./A. of total nitrogen. When switching to a corn-after-corn rotation, that economic optimum rate range is slightly higher at 215 to 231 lb./A. units of total nitrogen. Variable weather, soils, nitrogen prices, and hybrids all have an impact and must be considered each year when determining how much total nitrogen to apply. New data indicates additional efficiency can be gained by utilizing 2x2x2 application systems, but additional years of research are needed.



Beck’s two-year data has consistently shown that sidedressing UAN deeper at a 5 to 6 in. depth vs. a 2 to 3 in. depth has increased yield. Sidedressing UAN deeper will place nitrogen closer to the root zone, and in hot and dry conditions, the deeper placement protects against volatilization loss.

Achieving a 5 to 6 in. sidedress depth with a UAN applicator in a no-till scenario or when field conditions turn dry and hard can be challenging. Slowing down will help, allowing the knife and coulter a better chance to maintain the desired depth.

If reaching the desired 5 to 6 in. depth is still a challenge, installing nitrogen sealers on the applicator is another option. Nitrogen sealers are coulters that run behind the knives to move dirt back over the slot to help prevent nitrogen volatilization. Four years of PFR data show an average yield gain of +4.7 Bu./A., with one year posting a 12.7 Bu./A. advantage.



Adding ammonium thiosulfate to your UAN sidedress application is a great option for delivering sulfur in season and providing some protection against nitrogen volatilization. A good starting point is to apply 1 lb. of sulfur for every 10 lb. of nitrogen. Similar to nitrogen, we have seen certain hybrids respond more to sulfur applications than others.

Nitrogen stabilizers are often added to UAN when sidedressing to help protect the crop from nitrogen loss. When selecting a nitrogen stabilizer, it’s important to match the product you’re using with the protection you need, whether volatilization, denitrification, or leaching. The success of these products is often determined by the subsequent weather.

Other products containing carbon sources are available and can be added to UAN to help stabilize nitrogen and increase yield. Two PFR Proven™* products to consider are Humika™ and Carbon Works Certain®. When applied with UAN at V3 sidedress, these products provided increased yield and a positive ROI when averaged over three years of data.


Nitrogen is an incredibly challenging molecule to study. Every year, every soil type and the logistics of every operation can impact results. In fact, the optimum NUE for any field can be dramatically different every year based on your soil type and the weather. For more insight into Beck’s best practices for nitrogen, CLICK HERE.

*For a product or practice to become PFR Proven, it needs to have been tested for a minimum of three years at multiple locations, it must provide a positive yield gain each year, and it must average a positive return on investment over the three-year period.

Humikais a trademark of Max Systems, LLC. Carbon Works Certain® is a registered trademark of Carbon Works, Inc. Practical Farm Research (PFR)® is a registered trademark and

PFR Proven™ is a trademark of Beck’s Superior Hybrids, Inc.

Beck's - Farmers At Heart® - revolutionized the customer seed buying experience by remaining true to a foundation built on faith, family, and farming. Founded in 1937, Beck's appreciates the farmers who have helped them become the largest family-owned retail seed company and the third-largest seed brand in the United States. The Beck family is now in its fifth generation of family members who work in the business to honor God and help farmers succeed. The Beck family and team of employees help farmers achieve success from generation to generation through authentic customer experiences, product diversity, seed quality, and performance. With a home office located in Atlanta, Ind., Beck's serves farmers throughout the Midwest and Mid-South. For more information about Beck's Superior Hybrids, Inc., visit www.beckshybrids.com.

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