Nitrogen (N) fertilizer remains one of the biggest expenses for Nebraska farmers, especially for growing corn. In 2025, the situation has become more complex as some growers face a tightening supply of urea ammonium nitrate (UAN) due to delayed imports, increased exports and disruptions at production facilities. As a result, UAN availability is constrained for some farmers during the key side-dress window. In this challenging environment, it is more important than ever for farmers to use nitrogen wisely and make every pound count. Here are some strategies to help you stretch your nitrogen dollars and protect yield.

1. Stick to the 4Rs of Nutrient Stewardship

A cornerstone of effective nitrogen management is the 4Rs framework: applying fertilizer at the Right Rate, at the Right Time, using the Right Source, and in the Right Place. Each element plays a critical role in maximizing nitrogen use efficiency (NUE) and minimizing environmental losses — especially under supply and cost pressures.

• Right Rate: To determine an accurate N rate for your field, the University of Nebraska–Lincoln (UNL) provides a digital Nitrogen Calculator. This tool allows growers to reassess and adjust N needs in real time based on current conditions, optimizing both yield potential and cost savings.
• Right Time: Nitrogen should be applied when the crop can use it most efficiently. A common strategy is to apply about 30% of the N at or before planting, then split the remainder into one to three applications between V6 and tasseling. This coincides with rapid corn growth and peak N uptake, particularly between the V6 and V12 stages.
• Right Source: With UAN in short supply, farmers may consider alternatives such as urea or anhydrous ammonia. Urea is readily available but must be incorporated into the soil shortly after application — ideally with 0.5-inch of rainfall or irrigation — to prevent volatilization losses. Anhydrous ammonia is effective and economical but requires specific equipment and adherence to safety protocols.
• Right Place: Regardless of the N source, applying nitrogen where roots can access it — via injection or incorporation — reduces the risk of loss and improves plant uptake. Aligning application with soil test data also prevents over-application and maximizes return on investment.

2. Use Precision Agriculture Tools

Precision agriculture offers powerful ways to use less N more efficiently. Soil and yield mapping help identify variability across fields, while crop canopy sensors can assess nitrogen demand in real-time. Variable rate technology (VRT), informed by imagery or sensor data, enables zone-specific application. These tools are especially valuable when N supply is limited, as they help prioritize nitrogen where it's needed most. 

3. Split Nitrogen Applications Strategically

Split nitrogen applications remain one of the most effective strategies to reduce risk during times of supply uncertainty. Farmers can start with a modest base rate at pre-plant or early vegetative stages using available nitrogen sources such as anhydrous ammonia, urea or manure. The remaining nitrogen can then be applied in-season, ideally timed to match peak crop demand — typically between the V6 and V12 growth stages, when corn takes up the most nitrogen. If UAN is not available for side-dress, consider using ammonia or surface-applied urea with a stabilizer, based on your equipment setup and timing constraints.

4. Consider Cover Crops for N Availability

Cover crops planted during the previous winter, such as cereal rye or clover, can provide valuable benefits by reducing off-season nitrogen losses. These crops scavenge residual soil nitrogen, lowering the risk of nitrate leaching and improving soil health. As they decompose, they gradually release nitrogen back into the system, enhancing nutrient availability for the following crop. In years when synthetic nitrogen supplies are limited or costly, cover crops can help reduce reliance on in-season fertilizer by contributing organic nitrogen to support early crop growth.

5. Adopt Enhanced Efficiency Fertilizers (EEFs)

Enhanced efficiency fertilizers (EEFs) such as urease inhibitors, nitrification inhibitors and polymer-coated urea can help retain applied nitrogen in the soil and reduce losses to the atmosphere or groundwater. This can be particularly useful when switching from UAN to urea in surface applications. Although these products have a higher upfront cost, they can reduce the need for additional applications and improve NUE, especially during weather or supply uncertainties. Applying suboptimal N rates — 10 to 20% below UNL recommendations — along with EEFs provides a practical approach to maintain yields while improving efficiency and profitability.

6. Utilize Manure and Organic Amendments

Manure and organic amendments are valuable nitrogen sources, especially during synthetic fertilizer shortages. Manure can supply a portion — or even all — of the season’s nitrogen requirement when applied based on crop needs and tested for nutrient content. Coordinating manure applications with crop demand and soil nutrient levels can reduce reliance on synthetic fertilizers while improving soil health. Find more in NebGuide G1335, “Determining Crop Available Nutrients from Manure”.

7. Test Your Soil, Crops and Irrigation Water

Soil and crop evaluation can help you know exactly how much nitrogen — among other nutrients — is available and, if needed, critical for making informed mid-season decisions. The pre-side-dress nitrate test (PSNT) can help determine whether additional nitrogen is needed. Remote sensing of crop canopy reflectance helps to quantify the need for in-season N. These diagnostic tools are especially important when fertilizer must be conserved or rationed due to supply issues. Testing N input from irrigation water can help save N fertilizer and other nutrients, such as sulfur. Combining the irrigation water test with the amount of irrigation will deliver the amount of N credit from irrigation.

8. Account for Residual Nitrogen and Soil Mineralization

Farmers should also consider the contributions of residual nitrogen and mineralization when calculating in-season needs. Residual nitrate from the previous crop or fall fertilizer applications can significantly reduce the need for additional N. Similarly, organic matter in the soil continues to mineralize nitrogen throughout the season, providing a background supply that should be accounted for before applying fertilizer.

9. Minimize Nitrogen Losses

Minimizing nitrogen loss is essential under any condition, especially when fertilizer is expensive or scarce. Incorporating fertilizers into the soil can reduce volatilization or runoff. Avoiding applications ahead of heavy rainfall reduces leaching. The use of nitrification inhibitors with ammonia or urea can slow the conversion of ammonium to nitrate, reducing the risk of N leaching.

10. Work with UNL Extension and Decision Tools

Finally, UNL offers a wide range of tools and expertise to support producers. Based on field-specific data, the UNL Nitrogen Calculator can help determine the economically optimal nitrogen rate (EONR). Local extension personnel for your county can assist with nitrogen planning, rate adjustments and source substitutions based on current conditions and product availability.

Takeaway for 2025

The current UAN shortage is tough, but it is also an opportunity to fine-tune your nitrogen management by using science-based nitrogen strategies. Producers can protect yields and reduce costs by using precision applications, soil testing, cover crops, EEFs and manure, even under supply pressure. A proactive, adaptive approach to nitrogen management will help Nebraska growers maintain profitability and sustainability during this challenging season. For more help, reach out to your local Nebraska Extension office or use the many decision tools available from UNL.